In this section I am talking about marijuana and also cannabis, which are both the same thing.

Also known as

weed, skunk, sinsemilla, sensi, resin, Puff, Pot, Marijuana, herb, hashish, hash, grass, ganja, draw, Dope, Bud, bhang, blunt, green, joint, Mary Jane, reefer, smoke, trees, boom, gangster, hemp, black, blast, blow, Bob Hope, bush, ganga, Northern Lights, sensemilla, spliff, wacky backy, zero shit, gold seal, rocky, Indica, sens, haze, zero zero, red seal, temple balls, or by country of origin, e.g. Thai sticks, Lebanese, Leb, Morrocan, Nepalese, Paki black, afghani, Turkish,etc.




Cannabis is a natural drug (compared to a man-made synthetic one) that comes from varieties of Cannabis Sativa, which is the same plant that hemp comes from. This plant grows in various parts of the world (including the UK) and can reach up to 15 feet in height. Cannabis is slightly different from other drugs, in that it doesn't clearly fall into the simple drug categories such as: stimulant (speeds up body's reactions), depressant (slows own body's reactions) or hallucinogen (distorts senses). However, it probably falls more into the hallucinogen category rather than the others but, depending on the type, it can have effects that fall into the other categories [1].

It also comes in a more concentrated, resinous form, called hashish, and as a sticky black liquid called hash oil. The name 'hemp' usually refers to low-THC varieties of cannabis that are grown for industrial uses (i.e., rope, clothing). According to the 2000 National Household Survey on Drug Abuse, an estimated 34% of Americans over the age of 12 have used marijuana in their lifetime [2]. The average potency of the drug has increased substantially in the last twenty years, although it can vary significantly, depending on the type of plant and its origin. The main psychoactive chemical in the plant is THC (delta-9-tetrahydrocannabinol), although marijuana contains some 400 other chemicals as well [3].

What does it look like?

Marijuana is a dry, shredded green/brown mix of flowers, stems, seeds, and leaves from the Cannabis sativa plant. The mixture typically is green, brown, or gray in colour and may resemble tobacco [2].

  • hash - dark brown, black, tar-like substance (resin),
  • herbal - a mixture of leaf, seed and buds from the female cannabis plant. High quality contains just the buds (often grown indoors, known in the UK as 'skunk'),
  • oil - light brown, viscous (sticky) oil-like substance, similar to honey [1].


Marijuana comes from the Indian hemp plant, and the part that contains the 'drug' is found primarily in the flowers (commonly called the 'buds') and much less in the seeds, leaves, and stems of the plant.

Marijuana, when sold, is a mixture of dried out leaves, stems, flowers and seeds of the hemp plant. It is usually green, brown or gray in colour.

Hashish is tan, brown or black resin that is dried and pressed into bars, sticks or balls. When smoked, both marijuana and hashish give off a distinctive, sweet odour.

There are over 400 chemicals in marijuana and hashish [4]. The chemical that causes intoxication or the 'high' in users is called THC (short for tetrahydrocannabinol). THC creates the mind-altering effects that classifies marijuana as a 'drug'.

Plants, like animals, have traits that protect them in the wild. Plants can have colours or patterns that camouflage them from predators, or they can contain poisons or toxins that, when eaten, make animals sick or alter their mental capacity, putting them at risk in the wild. THC is the protective mechanism of the marijuana plant.

Intoxication literally means 'to poison by taking a toxic substance into your body'. Any substance that intoxicates causes changes in the body and the mind. It can create addiction or dependence, causing a person to want to take that drug even if it harms him or her.

You may have heard someone say that because marijuana is a plant, it's 'natural' and so it's harmless. But it's not. Hemlock, a poisonous plant, is also 'natural', but it can kill.

The other thing to know is that burning dried leaves and buds and inhaling the smoke into your lungs is definitely not 'natural' and like smoking cigarettes, can be harmful to your body.

As for the medical uses of marijuana, it contains another chemical called CBD (short for cannibidiol). This is the substance most often associated with creating medical benefits. Unlike THC, CBD does not cause a high [5]. Its medical benefits are still being studied, as are methods to breed marijuana plants with high CBD and low THC for medical use.

Marijuana is a drug like alcohol, cocaine, or ecstasy. And like these other drugs, it has side-effects that can be harmful [6].

Cannabis grows in many parts of the world. The main centres of commercial production include north and west Africa, south America, middle and far East. Increasingly being grown indoors in Europe [7].


It is estimated that cannabis has been used at least once (lifetime prevalence) by about 77 million Europeans, that is almost one in four of all 15- to 64-year-olds. Considerable differences exist between countries, with national prevalence figures varying from 1.6% to 32.5%.

Among young adults (15- to 34-year-olds), lifetime prevalence of cannabis use varies considerably between countries, from 1.0% to 45.1%, with a weighted European average of 32.2%. Last year use of cannabis in this age group ranges from 0.4% to 17.5%. It is estimated that about 15.4 million (11.7%) young Europeans have used cannabis during the last year and 6.5% during the last month.

Cannabis is the illicit drug most likely to be tried by European school students. In the 24 EU Member States and Norway with ESPAD surveys in 2011, lifetime cannabis use among 15- to 16-year-olds ranged from 5% in Norway to 42% in the Czech Republic. Gender ratios also varied from unity to about 2.5 boys to each girl.

A significant minority of cannabis users consume cannabis intensively. Daily or almost daily cannabis use is defined as use on 20 or more days in the month preceding survey. Data from 22 countries, suggest that around 1% of adults (15- to 64-year-olds), at least three million, report using the drug in this way. Over two-thirds of these are aged between 15 and 34 years, and in this age group, over three-quarters are male [8].

According to Home Office statistics on drug use in from 2016 cannabis continues to be our most commonly used illegal drug, with 6.5% of adults aged 16 to 59 having used it in the last year (around 2.1 million people).

Among younger adults aged 16 to 24, cannabis was also the most commonly used drug, with 15.8 per cent having used it in the last year (around 975,000 young adults) [9].

Street price

In 2011, the mean retail price of cannabis resin in the EU was reported as varying from EUR 3 (Portugal) to EUR 18 (Malta) per gram, while the price of herbal cannabis ranged from EUR 5 (Spain) to EUR 24 (Bulgaria) per gram. Both the mean retail prices of cannabis resin and herbal cannabis rose slightly over the period 2006 - 11 (9% and 12% respectively) in EU countries reporting sufficient data for trend analysis [8].

According to Druglink's Street Drug Trends 2012 Survey, average prices per quarter ounce of standard quality herbal resin were £37. For good quality herbal cannabis the price rose to £55, while for resin cannabis the average price was £27 [9].

Cannabis pricing has been relatively stable for a long time, though does experience wild fluctuations at times of shortage ('droughts'). Cannabis pricing is usually by weight, though small amounts may be sold in £5 or £10 deals. Often sold by imperial measures, weights are based on ounces, and divisions of an ounce. Typically, an ounce of resin sells for between £80 and £120, often dependent on quality. After this, prices become relatively higher; half-ounces are usually around £50, quarters are around £30, eighths are around £20, and the smallest amount sold are £12 - £15. Herbal cannabis, and, from time-to-time, resin, are sold by the gramme. Prices are broadly equivalent, at a rate of roughly 28 grammes to the ounce. Good quality strains are more expensive [10].

Why take it?

Sought after effects

  • mellow, calm feeling,
  • sense of well-being,
  • changes in senses, especially eating hash cakes,
  • often thought of as an aphrodisiac,
  • stimulates appetite,
  • pain killer (analgesic) [1],
  • relaxation,
  • euphoria,
  • hilarity [7].

Undesired effects

  • increase in pulse rate,
  • drop in blood pressure,
  • sense of lethargy,
  • concerns about the effect on the mental health of the young,
  • can affect short term memory,
  • can affect coordination [1],
  • anxiety,
  • paranoia,
  • confusion,
  • low blood pressure,
  • short term memory loss,
  • increased appetite [7].



Children raised with parents or older siblings who frequently use marijuana openly grow up thinking this is a normal behaviour and have no reason to believe there is any stigma attached to it. Since a large number of adolescents and college-age students smoke the substance it is further normalised. Thus, the genetic predisposition to use the substance, modeling from family members and viewing it as a normalised behaviour based on coming into contact with a number of peers who also use the substance, combine to lead to an increased risk of the individual developing an addiction [11].

Brain Chemistry

Research has shown THC binds to specific receptor sites in the brain called cannabinoid receptors (CBRS). These receptors recognize the THC as a similar chemical compound which naturally occurs in the brain which influence memory, pleasure, sensory perception, concentration, coordination, thinking, and time perception. Sometimes individuals have difficulties with certain of these areas and when they come into contact with marijuana learning it helps to correct the problem. This hooks them and they continue to use it, not wanting to return to their previous state [11].


The more individuals smoke marijuana, the higher the likelihood they will need more of the drug to induce the desired effects. Studies suggest as the strength of THC and CBD in marijuana rises - increasing the amount in the person's system - so does the risk for addiction. Individuals who begin using marijuana in their teen years are more likely to develop a problem with marijuana addiction later in life due to the length of time they have been using it. Unfortunately, once an addiction to marijuana has developed, it can be extremely challenging to overcome without effective professional help [11].


Marijuana causes intense paranoia and delusions while the user is stoned which can exacerbate psychotic behaviours. Since they don't know their beliefs are delusional, they continue smoking the substance so as not to alter their experiences in order to be certain they can predict their actions and know how to handle the situations they believe are occurring [11].

What are the different forms?

Although it's all from the same plant, cannabis comes in many different forms [12].

Hash or cannabis resin

  • Hash is a black or brown soft lump made from the resin of the cannabis plant. It's much less common in the UK than it used to be [12].
  • A black or brown lump. Not seen in the UK very much anymore [9].
  • Cannabis resin used to dominate the UK market until around 10 years ago, before being supplanted by skunk. As with herbal cannabis there are many different types. Pharmacologically the main difference between resin and herbal cannabis is that resin typically contains higher levels of CBD. Resin is prepared either by sieving the herbal material through progressively finer meshes and compressing the resulting material, or by hand-rubbing and scraping the resin from the flowers of plants and pressing the resulting material into blocks or fashioning into 'fingers' or 'medallions' or 'Temple Balls'. The first method is characteristic of resin from the Arabic-speaking areas, the second method of resin from the Indian sub-continent.
    • Soap-Bar resin remains the most common variety available in the UK, this is generally considered to be of low to medium quality, and is imported from North Africa in the form of 9oz or quarter-kilo pillow-shaped blocks known as 9-bars. It is hard in texture with a shiny, usually curved outer surface and an inner surface ranging from yellowish-green to a dark reddish-brown. Potency typically between 3% and 7% THC. Much soap-bar resin is heavily adulterated, a research study by Edinburgh University found instances of adulteration with substances including - beeswax, turpentine, milk powder, ketamine, boot polish, henna, pine resin, aspirin, animal faeces, ground coffee, barbiturates, glues and dyes plus carcinogenic solvents such as Toluene & Benzene.
    • Higher quality forms of Moroccan resin have become increasingly available over the past decade, the most common being flat-press. This is found in flat slabs of 100 or 200g in weight typically 10 - 15mm thick, mid-brown in colour. Typical THC content 5% - 12%. Lebanese resin, common in the 1960's - 1980's has effectively disappeared from the UK market.
    • Resin from Asia (Pakistan, Afghanistan, India) is normally dark-brown to black in colour (known as black hash), and is soft and malleable in texture. This used to be common in the UK but is now rarely found. Typical THC contents 3% - 10%, occasionally higher for premium varieties.
    • Growers of cannabis are increasingly producing home-made resin using shakers or other forms of extraction, this material, known as skuff or bubble hash can be extremely potent (have encountered up to 59% THC), but is rarely sold [13].


  • Grass, also known as weed, is made from the dried leaves and flowering parts of the female cannabis plant and looks like tightly packed dried herbs. This traditional grass was normally imported and much weaker than the 'skunk' types of cannabis usually sold now [12].
  • This is the most common way to find cannabis. It is composed of the dried leaves and flowering parts of the female cannabis plant and resembles compressed dried herbs [9].
  • Herbal cannabis can appear in two other forms,
    • the first is bush, which is grown outdoors in the tropics (Caribbean, Africa, SE Asia) and compressed into blocks before being imported into the UK. This is readily distinguished from skunk cannabis via the presence of seeds which can comprise up to 30% of the total weight. Bush typically contains 2% - 10% THC. It is usually referred to via country of origin if known, or otherwise as 'bush' or 'weed'.
    • The final type of herbal cannabis is 'homegrown' this can either represent material grown outdoors or the remains left over when skunk has been harvested from plants, typically a mix of leaf material and small or immature flowering tops. Most leaf material is simply thrown away by growers. Potency can vary from under 1% for poor quality leaf (or hemp) to around 10% for the smaller leaves surrounding the buds or smaller flower buds [13].


  • Skunk is a group of different types of strong herbal cannabis. Sinsemilla, homegrown cannabis, netherweed are all different types of cannabis that are part of this 'skunk' group. Cannabis can seriously affect your mind and body and this group could pose even more risks because of their strength [12].
  • a strong form of herbal cannabis that consists just of the buds and is often grown indoors in the UK. Much of the cannabis in use in the UK is homegrown either under grow lights or in greenhouse conditions using 'hydroponic' techniques (i.e. growing plants in nutrient-rich liquids rather than in soil). This produces a stronger more potent form of the drug which is sometimes referred to as Skunk. In fact skunk is only one of 100 or so varieties of cannabis plant which have high levels of tetrahydrocannabinol (THC) [9].
  • Cannabis now most commonly appears in herbal form commonly known as skunk. The majority of this is grown in the UK or imported from Western Europe, grown indoors under lights. Although skunk started life as a trade name for a specific pedigree variety of cannabis, the term has come to be used to refer to any type of cannabis in the form of unfertilised female flowering tops with little or no leaf present. Skunk typically contains between 8% and 20% THC, occasionally higher. There are many 'brands' of skunk-type cannabis which vary in parentage, potency, appearance and flavour. Two of the more common would be -
    • Cheese - a highly pungent variety with high THC levels (typically over 15%)
    • Purple Haze which has purple-coloured flowers (virtually black when dried) but only mid-level THC content (typically 6% - 13%) [13].

Cannabis oil

  • Cannabis oil is a sticky, dark honey-coloured substance and is much less common. [7].
  • Rarely seen, cannabis oil is a sticky, thick yellowy/brown liquid [9].

Hash oil

  • The final type of cannabis, also rare, is hash oil which is an extract of plant material using organic solvents to dissolve the THC, the solvent is then evaporated off to leave a greenish-brown sticky viscous oil. Potencies can again be extremely high [13].

How long do its effects last?

Onset of effects

  • smoked - 1 - 10 minutes [14], 0 - 10 minutes [15], 2 - 10 minutes [16].
  • oral - 30 - 120 [14], [15], 20 - 120 minutes [16].


  • smoked - 15 - 30 minutes [15].
  • oral - 2 - 5 hours [15].

Duration of effects


  • smoked - 2 - 24 hours [14], 45 - 180 minutes [15].
  • oral - 6 - 24 hours [14], 6 - 12 hours [15].


The pharmacology of cannabis is complicated by the presence of a wide range of cannabinoids. At small doses, cannabis produces euphoria, relief of anxiety, sedation and drowsiness. In some respects, the effects are similar to those caused by alcohol. Anandamide has been identified as the endogenous ligand for the cannabinoid receptor and has pharmacological properties similar to those of THC. When cannabis is smoked, THC can be detected in plasma within seconds of inhalation; it has a half-life of 2 hours. Following smoking of the equivalent of 10 - 15 mg over a period of 5 - 7 minutes, peak plasma levels of Δ9-THC are around 100 μg/L. It is highly lipophilic and widely distributed in the body. Two active metabolites are formed: 11-hydroxy-Δ9-THC and 8β-hydroxy-Δ9-THC. The first is further metabolised to Δ9-THC-11-oic acid. Two inactive substances are also formed - 8α-hydroxy-Δ9-THC and 8α,11-dihydroxy-Δ9-THC - and many other minor metabolites, most of which appear in the urine and faeces as glucuronide conjugates. Some metabolites can be detected in the urine for up to 2 weeks following smoking or ingestion. There is little evidence for damage to organ systems among moderate users, but consumption with tobacco carries all of the risks of that substance. Most interest in the adverse properties of cannabis has centred on its association with schizophrenia, although it is still unclear if there is a causative relation between mental health and cannabis. Fatalities directly attributable to cannabis are rare [8].

The most psychoactive cannabinoid found in the cannabis plant is tetrahydrocannabinol (or delta-9-tetrahydrocannabinol), commonly known as THC [15]. Other cannabinoids include delta-8-tetrahydrocannabinol, cannabidiol (CBD), cannabinol (CBN), cannabicyclol (CBL), cannabichromene (CBC) and cannabigerol (CBG); they have less psychotropic effects than THC, but may play a role in the overall effect of cannabis [17]. The most studied are THC, CBD and CBN [18].

THC appears to alter mood and cognition through its agonist actions on the CB1 receptors, which inhibit a secondary messenger system (adenylate cyclase) in a dose dependent manner. Via CB1 activation, THC indirectly increases dopamine release and produces psychotropic effects. Cannabidiol acts as an allosteric modulator of the mu and delta opioid receptors [19]. THC also potentiates the effects of the glycine receptors [20]. However, the role of these interactions and how they result in the cannabinoid high continues to remain elusive [15].

Our understanding of how cannabis works on the brain is still less than complete. The strength or purity of the drug is measured as a percentage according to the amount of THC it contains, calculated against weight.

Cannabis contains over 400 chemicals; some 60 plus of these are chemically unique and are known as cannabinoids. Delta-9 tetrahydrocannabinol THC is generally regarded as the alkaloid primarily responsible for the plant's psychoactive effects, though there is on-going research into the pharmacological action of the spread of cannabinoids. Medical users are particularly attracted to Cannabidiol CBD for its sedative/anxiolytic properties. and research has been carried out on these effects. CBD is also believed by some users and researchers to modify the effect of THC.

Cannabis works by binding to specific cannabinoid receptors (CB1 and CB2) within the cerebral cortex, hippocampus, hypothalamus, cerebellum, basal ganglia, brain stem, spinal cord and amygdala, a very diverse set of locations associated with diverse functions, providing the neurological substrate of the great variety of experiential effects associated with cannabis ingestion. As in the case of opium, the discovery of cannabinoid receptors in the human brain and nervous system for chemicals derived from plants led to a search for the endogenous alkaloid to which these receptors would naturally bind; an endogenous cannabinoid was duly discovered in 1988 and named anandamine, after ananda, the Sanskrit word for bliss [1].

The main active ingredients of the plant marijuana is derived from are -


THC (tetrahydrocannabinol, or delta-9-tetrahydrocannabinol) which offer mild to moderate analgesic effects. [[THC}]]is sometimes used to treat pain; though it's not the first substance of choice for analgesia. This chemical compound increases hunger and produces a sense of relaxation, fatigue and in some cases can result in a decrease of aggression. Limited research also shows some support for the efficacy of THC in treating nausea and vomiting [13].


Some studies show this compound to lead to alertness while others have demonstrated it causes a sedating effect. There has been some support indicating that CBD can relieve the symptoms of inflammation, nervousness, seizures and nausea. Some oncologists express the belief CBD may impede the advancement of cancer cells. More recent studies have also shown CBD may be helpful in treating atypical psychosis and schizophrenia along with dystonia, or involuntary muscle movements or contractions, sometimes exhibited by individuals with these disorders [13].


Lethal dosage

At present, it is estimated that the LD50 of cannabis is around 1:20,000 or 1:40,000. This means that, in order to induce death, a cannabis smoker would have to consume 20,000 to 40,000 times as much cannabis as is contained in one cannabis cigarette. A smoker would theoretically have to consume nearly 1,500 pounds of cannabis within about 15 minutes to induce a lethal response [15].


  • full tolerance is reached/develops with prolonged and repeated use,
  • decreases to half after 1 - 2 weeks,
  • returns to baseline after 2 - 3 weeks [15].

Tolerance to many of the effects of cannabis develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 1 - 2 weeks for the tolerance to be reduced to half and 2 - 3 weeks to be back at baseline (in the absence of further consumption). Cannabis presents cross-tolerance with all cannabinoids, meaning that after the consumption of cannabis all cannabinoids will have a reduced effect. The mechanisms that create this tolerance to THC are thought to involve changes in cannabinoid receptor function [15].

Mode of use

Cannabis is consumed in many different ways -

  • Smoking typically involves inhaling vaporised cannabinoids ('smoke') from small pipes, bongs (portable versions of hookahs with water chamber), paper-wrapped joints, tobacco-leaf-wrapped blunts, and other items [21]. Rolled in 'joints', with or without tobacco (marijuana) [1].
  • Vaporisers heat herbal cannabis to 165 - 190°C (329 - 374°F), causing the active ingredients to evaporate into a vapour without burning the plant material (the boiling point of THC is 157°C (315°F) at 760 mmHg pressure) [22].
  • Cannabis tea contains relatively small concentrations of THC because THC is an oil (lipophilic) and is only slightly water-soluble (with a solubility of 2.8 mg per litre) [23]. Cannabis tea is made by first adding a saturated fat to hot water (e.g., cream or any milk except skim) with a small amount of cannabis [24].
  • Edibles are cannabis added as an ingredient to one of a variety of foods.
  • Sublingual/buccal consumption typically involves the absorption of cannabinoids through the membranes inside the mouth (usually through a candy or tincture).
  • Tincture.
  • Topical consumption typically involves the use of either a cream or lip balm containing cannabinoids absorbed through the skin [15].
  • Inhaled - in 'pipes' or 'bongs'/'buckets', inhaled off hot knives or through a vaporiser [1].
  • Swallowed - eaten (hashish); prepared as a 'butter', baked in foods such as cakes and mixed with drinks such as tea ('cannabis tea') or spirits ('Green Dragon') and drunk [1].

Cannabis is usually smoked, often mixed with tobacco or in a smoking device (bong). Because THC has a low water solubility, ingestion of cannabis leads to poor absorption. The average 'reefer' cigarette contains around 200 mg of herbal cannabis or cannabis resin [8].

Various methods of smoking marijuana include rolling it into joints or blunts. Smoking through a pipe or bowl, through a waterpipe (or bong or a vaporiser are also common methods. While marijuana is most often smoked, it can also be ingested. The drug can be ingested alone or cooked into food, most notoriously in 'hash brownies'. In addition, it can be used to brew tea or 'bhang', a highly potent beverage originating from India [25]. The effects of smoking are typically felt within a few minutes and can peak in 10 to 30 minutes. Short-term effects from smoking generally wear off within 2 to 3 hours. And when eaten, the effects do not appear for 30 to 60 minutes, but can last up to 6 hours [26]. It is important to note, however, that the effects of the drug can be very different than expected if the marijuana has been laced with other drugs [3].

Usually smoked in a hand-made cigarette called a Joint, j, Reefer or Spliff. It is often mixed with tobacco, or in a pipe or water pipe (Bong). Other, home-made, devices may also be used for smoking, such as hot knives. It can also be baked in cakes or other foods and eaten [7].

Signs of usage

  • The smell - skunk cannabis has a distinctive and penetrating odour which persists on clothing and furnishings.
  • Paraphernalia - items associated with cannabis smoking would include cigarette papers (particularly if packets are partially torn up), broken cigarettes, torn card, empty/used small resealable plastic bags, grinders, 'roach ends', as well as pipes, bongs, digital scales etc.
  • Appearance - contrary to the opinion of some, cannabis has no effect on pupil size, however reddened conjunctivae is consistent with 'stoned' intoxication (among other possibilities).
  • Clothing - pinhole burns from resin [13].


Cannabis has a number of different effects. It is classed as a sedating and hallucinogenic drug. Its effects can turn out to be pleasant or unpleasant -

  • Taking cannabis can make people feel chilled out, relaxed and happy, and they may get the giggles or become very talkative.
  • It can make you more aware of your senses, and the hallucinogenic effects can even give you a feeling of time slowing down.
  • It can make you feel very hungry - this is sometimes called 'getting the munchies'.
  • Some people have one or two drags on a joint and feel light-headed, faint and sick. This is sometimes called a 'whitey'.
  • Cannabis may cause feelings of anxiety, suspicion, panic and paranoia [12].

Immediate effects

  • increased heart rate,
  • lessened coordination and balance,
  • a 'dreamy', unreal state of mind,
  • depression,
  • sleepiness [27].

Short-term effects

  • short-term memory problems,
  • severe anxiety, including fear that one is being watched or followed (paranoia),
  • very strange behaviour, seeing, hearing or smelling things that aren't there, not being able to tell imagination from reality (psychosis),
  • panic,
  • hallucinations,
  • loss of sense of personal identity,
  • lowered reaction time,
  • increased heart rate (risk of heart attack),
  • increased risk of stroke,
  • problems with coordination (impairing safe driving or playing sports),
  • sexual problems (for males),
  • up to seven times more likely to contract sexually transmitted infections than non-users (for females) [28], [29], [30].
  • dry mouth,
  • feeling relaxed and sleepy,
  • increased appetite,
  • quiet and reflective mood,
  • spontaneous laughter and excitement [31], [32].
  • munchies - they are hungry and will eat anything and everything [32].

If a large amount or a strong batch is taken, the following may also be experienced -

  • bloodshot eyes,
  • blurred vision,
  • clumsiness,
  • increased heart rate,
  • low blood pressure,
  • mild anxiety and paranoia,
  • seeing and hearing things that aren't there,
  • slower reflexes,
  • trouble concentrating [31], [32].

Long-term effects

Regular use of cannabis may eventually cause -

  • decline in IQ - up to 8 points if prolonged use started in adolescent age,
  • poor school performance and higher chance of dropping out,
  • impaired thinking and ability to learn and perform complex tasks,
  • lower life satisfaction,
  • addiction - about 9% of adults and 17% of people who started smoking as teens,
  • potential development of opiate abuse,
  • relationship problems, intimate partner violence,
  • antisocial behavior including stealing money or lying,
  • financial difficulties,
  • increased welfare dependence,
  • greater chances of being unemployed or not getting good jobs [33].
  • dependence on cannabis,
  • financial, work and social problems,
  • flu,
  • learning difficulties,
  • low fertility in males and females,
  • memory loss,
  • mood swings,
  • needing to use more to get the same effect,
  • reduced sex drive,
  • regular colds [31], [34], [32].

Physical effects

  • appetite enhancement,
  • appetite suppression,
  • changes in gravity,
  • dehydration,
  • increased heart rate,
  • motor control loss,
  • muscle relaxation,
  • muscle spasms,
  • nausea,
  • nausea suppression,
  • pain relief,
  • perception of increased weight,
  • physical euphoria,
  • sedation,
  • seizure suppression,
  • spontaneous tactile sensations,
  • tactile enhancement,
  • vasodilation [15].

Visual effects

  • acuity suppression,
  • brightness alteration,
  • colour enhancement [15].

Cognitive effects

  • analysis enhancement,
  • anxiety,
  • anxiety suppression,
  • conceptual thinking,
  • creativity enhancement,
  • depersonalisation,
  • derealisation,
  • dream suppression,
  • emotion enhancement,
  • feelings of impending doom,
  • focus enhancement,
  • focus suppression,
  • immersion enhancement,
  • increased music appreciation,
  • information processing suppression,
  • laughter,
  • memory suppression,
  • mindfulness,
  • novelty enhancement,
  • paranoia,
  • personal meaning enhancement,
  • sleepiness,
  • suggestibility enhancement,
  • time distortion,
  • thought connectivity,
  • thought deceleration [15].

Auditory effects

  • auditory distortion,
  • auditory enhancement [15].



  • relaxation,
  • analgesic (painkiller) [14].


  • giggling,
  • loss of inhibition [14].


  • low carcinogenic risk when smoked (due to combustion of other materials) [14].


Tolerance builds up rapidly after a few doses and disappears rapidly after a couple of days of abstinence. Heavy users need as much as eight times higher doses to achieve the same psychoactive effects as regular users using smaller amounts. They still get stoned but not as powerfully.

Over time and with a high level of use, a pot smoker's brain becomes desensitised to THC (tetrahydrocannabinol), which is the active ingredient in marijuana. Tolerance also develops because THC is stored in the fat cells of the body. It can take up to several weeks for a regular weed smoker's body to be completely free of the presence of the drug.

One effect of cannabis you can't develop tolerance to is 'the stimulatory effect on the appetite' or munchies [35].


No fatal overdoses associated with cannabis use have been reported as of 2010 [36]. A review published in the British Journal of Psychiatry in February 2001 said that "no deaths directly due to acute cannabis use have ever been reported" [37].


Cannabis can mess with your mind

Cannabis can mess with your mind and with your mood. It can disturb your sleep and can make you depressed. Some people will become anxious, panicky, and even aggressive. You might see or hear things which are not there (known as hallucinations) which may be frightening. For some people, cannabis causes hours or even days of anxiety, paranoia, delusions and hallucinations that usually only settles down after the cannabis is stopped.

  • Cannabis can freak you out - it can cause feelings of anxiety, suspicion, panic and paranoia.
  • For people with illnesses such as schizophrenia, cannabis can cause a serious relapse.
  • Regular cannabis use is known to be associated with an increase in the risk of later developing psychotic illnesses including schizophrenia; and if you have a family background of mental illness, you may also have an increased risk.
  • Cannabis can affect the way the brain works. Regular, heavy use makes it difficult to learn and concentrate and research has linked cannabis use to poor exam results. This is a potentially serious risk if you're young, when the brain is still developing. People who take a lot of cannabis can also find they lack motivation.
  • A recent review of cannabis research published in the British Medical Journal found those driving under the influence of cannabis had nearly double the risk of a crash [12].

How does marijuana affect the brain?

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Short-term effects

When a person smokes marijuana, THC quickly passes from the lungs into the bloodstream. The blood carries the chemical to the brain and other organs throughout the body. The body absorbs THC more slowly when the person eats or drinks it. In that case, the user generally feels the effects after 30 minutes to 1 hour.

THC acts on specific brain cell receptors that ordinarily react to natural THC-like chemicals in the brain. These natural chemicals play a role in normal brain development and function.

Marijuana overactivates parts of the brain that contain the highest number of these receptors. This causes the 'high' that users feel [38]. Other effects include -

  • altered senses (for example, seeing brighter colours),
  • altered sense of time,
  • changes in mood,
  • impaired body movement,
  • difficulty with thinking and problem-solving,
  • impaired memory [38],
  • confusion,
  • memory loss,
  • paranoia,
  • laziness [7].

Long-term effects

Marijuana also affects brain development. When marijuana users begin using as teenagers, the drug may reduce thinking, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions.

Marijuana's effects on these abilities may last a long time or even be permanent.

For example, a study showed that people who started smoking marijuana heavily in their teens and had an ongoing cannabis use disorder lost an average of eight IQ points between ages 13 and 38. The lost mental abilities did not fully return in those who quit marijuana as adults. Those who started smoking marijuana as adults did not show notable IQ declines [39], [38].

  • habituation,
  • paranoia,
  • damage to lung tissue,
  • risk of developing mental health problems [7].

Other health effects

Physical effects

Breathing problems

Marijuana smoke irritates the lungs, and frequent marijuana smokers can have the same breathing problems that tobacco smokers have. These problems include daily cough and phlegm, more frequent lung illness, and a higher risk of lung infections. Researchers still do not know whether marijuana smokers have a higher risk for lung cancer [38].

A pot smoker also has other lung issues they need to worry about when they inhale this substance. The person will have similar health problems to someone who uses tobacco exclusively, such as chronic coughing and an increased level of phlegm production. Regular marijuana use also increases the risk of chest illnesses and lung infections. These respiratory issues may mean that a pot smoker is more likely than someone who smokes tobacco to take time off from work [35].

Increased heart rate

Marijuana raises heart rate for up to 3 hours after smoking. This effect may increase the chance of heart attack. Older people and those with heart problems may be at higher risk [38].

Lighting up a joint of marijuana and taking a toke has an immediate effect on the user's heart. Using the drug causes the individual's heart rate to increase between 20% and 100%. The elevated heart rate may last for as long as three hours.

The higher heart rate creates a strain on the weed smoker's heart. As the heart beats more rapidly, the individual may experience cardiac arrhythmia. The risk of heart attack increases in the first hour after using marijuana. People who are older or who have a heart condition are especially at risk for a myocardial infarction.

It may be tempting to think of the risk of heart attack as something that only applies to middle-aged people who are overweight or who otherwise don't take good care of themselves, but this is not necessarily the case. A heart attack can happen to people who don't have a known history of cardiac issues, and the fact that using cannabis can increase the risk of this outcome is nothing to discount [35].

Problems with child development during and after pregnancy

Marijuana use during pregnancy is linked to increased risk of both brain and behavioural problems in babies. If a pregnant woman uses marijuana, the drug may affect certain developing parts of the fetus's brain. Resulting challenges for the child may include problems with attention, memory, and problem-solving. Additionally, some research suggests that moderate amounts of THC are excreted into the breast milk of nursing mothers. The effects on a baby's developing brain are still unknown [38].


Smoking any drug is unhealthy, and cannabis is no exception. Cannabis smoke actually contains higher concentrations of carcinogenic polycyclic aromatic hydrocarbons (PAHs) than tobacco smoke. Cannabis smokers generally inhale more smoke for longer, depositing more than 4 times as much tar in their lungs as those who smoke cigarettes. To balance this, they smoke fewer joints and smoke less often.

Combining cannabis and tobacco is even worse. If you are a heavy smoker of cannabis and tobacco joints (more than 10 a day), you are significantly increasing your risk of developing lung disease. Recent studies show that the greatest pre-cancerous abnormalities appear in those who smoke the two drugs together.

Another important factor is that most cannabis smokers stop when they reach their 30s. Long term surveys of cigarette smokers showed that those who stop before the age of 35 had only a very slightly increased risk of lung cancer. The same may apply to cannabis [35].

Mental effects

Long-term marijuana use has been linked to mental illness in some users, such as -

  • temporary hallucinations - sensations and images that seem real though they are not,
  • temporary paranoia - extreme and unreasonable distrust of others,
  • worsening symptoms in patients with schizophrenia [38].


A common side-effect, usually for first time or early users, is anxiety, panic, paranoia and feelings of impending doom. However, these effects disappear within hours. Reassurance and a supportive environment also help.

There are also anecdotal reports of long-term users 'turning a corner' in their cannabis use, where they can no longer enjoy the experience as cannabis triggers paranoia and anxiety attacks.

In a recent study, between 10% - 15% of people who smoked cannabis reported 'paranoid' or 'confused' feelings as a disadvantage of smoking cannabis. And over 27% reported 'anxiety' as a regular or occasional effect. Around 30% gave 'negative experiences' as their reason for permanently quitting cannabis [35].


There is general agreement that heavy cannabis use can precipitate schizophrenic episodes in those with the disorder, but there is no evidence that it can cause the underlying psychotic disorder. Heavy cannabis users can exhibit long-lasting toxic psychosis involving delusions and hallucinations that can be incorrectly - and dangerously - diagnosed as a schizophrenic illness.

In some cases, a person with mental health issues will turn to marijuana as a way to self-medicate. Rather than providing effective treatment for the underlying issue, the marijuana use only serves to mask the symptoms. Even if the individual consulted with a healthcare professional to get treatment, the drug use makes it more challenging to do so effectively [35].

Cannabis can mess with your body

  • Tobacco and cannabis share some of the same chemical 'nasties', so, like smoking tobacco, smoking cannabis can make asthma worse, can cause wheezing in people without asthma and can even lead to lung cancer.
  • When people mix cannabis with tobacco they're also taking on all the risks associated with smoking tobacco, which can range from coughs and chest infections to cancer or heart disease.
  • It can increase the heart rate and affect blood pressure, which can be especially harmful for those with heart disease.
  • It is reported that frequent use of cannabis may affect fertility. It can cut a man's sperm count and can suppress ovulation in women.
  • If you're pregnant, smoking cannabis may increase the risk of your baby being born smaller than expected [12].


Cannabis may be 'cut' with other substances to increase the weight and the dealer's profits.

  • Impurities in cannabis may include a variety of substances, with laboratory-confirmed reports of glass and pesticides being found in herbal forms of cannabis; and with hash/resin frequently being mixed with a range of substances to increase weight and the dealer's profits. In April 2010, a study, looking into contaminants in drugs reported that there were cases of cannabis being adulterated with henna, lead and aluminium.
  • Any impurities you smoke could be inhaled in to the lungs alongside the wide range of chemicals naturally found in cannabis.
  • Tobacco and cannabis share some of the same chemical 'nasties', so, like smoking tobacco, smoking cannabis can make asthma worse and can cause wheezing in people without asthma. Smoking it may damage your lungs and if you use it regularly for a long time it may lead to lung cancer.
  • When people mix cannabis with tobacco they're also taking on all the risks associated with smoking tobacco, which can range from coughs and chest infections to cancer or heart disease [12].

In 2011, cannabis resin at retail level in Europe was reported to have an average THC content that varied from 4% (Hungary) to 16% (the Netherlands), while herbal cannabis potency ranged from 1% (Hungary) to 16% (the Netherlands), 'An overview of cannabis potency in Europe' and 'Cannabis production and markets in Europe'). Herbal cannabis produced by intensive indoor methods may have an average potency two or three times greater than that of imported herbal cannabis, although the two overlap. In some EU countries there is licensed cultivation of cannabis for fibre production (hemp), but the THC content of these plants is less than 0.3%. Small amounts of cannabis resin are illicitly produced in the EU (e.g. nederhasj). Like cannabis oil, this product may have THC content in excess of 30% [8].

Resin, like other drugs, can be cut with other substances to bulk it out. The effects and health risks associated with this are difficult to determine depending what goes in to the resin mix. Substances like boot polish, animal dung and other drugs have been known to be added to cannabis resin [7].

The major concerns are products that have been cut, and contain little or no cannabis at all. Dried leaves, mixed herbs or any other leafy produce may be passed off as herbal cannabis. Mixtures of wax, henna, plastic or liquorice have been passed off as cannabis resin. However, most people buy off people they know rather than dealers on the street, so these risks are reduced.

The low grade 'soap-bar' resin sold in the UK is almost invariably low quality and contains potentially dangerous additived, including plastic and paraffin wax.

Herbal cannabis buds have also been contaminated, increasingly with small glass beads that have been sprayed on to the buds. There has been concern that inhalation of these beads can cause respiratory problems [10].


Cannabis is nowhere near as addictive as nicotine or alcohol but it is wrong to say it is not habit-forming. This 'soft' drug is one of the most widely used illegal substances in the United States. Some people report that they can use marijuana occasionally, or even regularly, without becoming addicted.

Many users compare their daily cannabis habit with dependency on caffeine (which is also an addictive substance). The UK Department of Health summed it up neatly: Cannabis is a weakly addictive drug but does induce dependence in a significant minority of regular users. Around 9% of users become addicted, although some studies estimate that over 50% of users have 'impaired control' over their use of cannabis. Of the 70 million Americans estimated to have tried the drug, around two million use it daily [35].

How do you know that your pot use has crossed the line into an addiction? The way you can tell whether you are in control over your pot smoking habit or if the drug is controlling you is to consider how much time and effort you are devoting to marijuana during the course of your day. When a good deal (or the majority) of your thoughts revolve around the last time you used marijuana, when you will be able to light up a joint again or where you will be able to buy some more weed, those are red flags that you have developed an addiction.

If you find yourself thinking about the quality of the last bag of grass you bought (whether you were happy with it or not) and wondering how the next one will stack up, you may be a marijuana addict. Spending a lot of time thinking about whether you have enough money to buy your dope and if you find you are short of cash, wondering how you are going to get the money is another sign of addiction to pot.

People who develop marijuana addictions tell themselves the same kinds of excuses that people who are addicted to nicotine, alcohol or other drugs do. If you have ever said (even to yourself) that you can quit any time you want to, but you can't seem to stay off the stuff, you are an addict. Making up excuses about why now isn't a good time to quit smoking dope, telling yourself, or telling those close to you that you will quit once some set of circumstances in your life have changed are also not good signs if you are trying to convince yourself that you are not addicted.

When your marijuana use gets to the point where you put it ahead of your work or educational pursuits, you are no longer just a recreational user. If you avoid spending time with your friends or family members so that you can get high, you are exhibiting another sign of addiction to pot [35].

Can you get addicted

The simple answer is 'yes, people do become dependent on cannabis'. This means you can get 'cravings' for cannabis, and may have difficulty staying off it even if you recognise using it has started to cause you problems.

And regular users can also get some unpleasant withdrawal symptoms on stopping, including irritability, mood changes, feeling sick, loss of appetite, difficulty sleeping; and even sweating, shaking and diarrhoea in some people.

You're also at real risk of getting addicted to nicotine, or staying addicted to it, if you roll your spliffs with tobacco.

If you feel that you have a problem with your cannabis use and want to stop or cut down, there are treatment services that can help you [12].

Dangerous interactions


  • Mushrooms - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • LSD - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • DMT - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • Mescaline - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • DOx - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • NBOMes - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • 2C-x - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • 2C-T-x - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • αMT - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics. Small amounts can reduce nausea with aMT but take care.
  • 5-MeO-xxT - Cannabis has an unexpectedly strong and somewhat unpredictable synergy with psychedelics.
  • Amphetamines - Stimulants increase anxiety levels and the risk of thought loops which can lead to negative experiences.
  • Cocaine - Stimulants increase anxiety levels and the risk of thought loops which can lead to negative experiences [14].


If you are a regular cannabis smoker (every day) and you stop smoking, you will experience some of the following withdrawal symptoms -

  • insomnia,
  • intense dreams,
  • irritability,
  • mild agitation,
  • nausea,
  • restlessness,
  • sleep disturbance,
  • sweats [35].

These symptoms, however, are usually mild and short-lived, lasting 2 to 4 days [35].

Giving up cannabis after using it for a long time is challenging, because the body has to get used to functioning without it. Withdrawal symptoms may last for only a week, but sleep may be affected for longer. Symptoms include -

  • aggressive behaviour,
  • angry behaviour,
  • anxiety,
  • chills,
  • cravings for cannabis,
  • irritability,
  • loss of appetite,
  • nightmares,
  • restless sleep,
  • sweating,
  • tremors,
  • upset stomach [32],
  • tension,
  • decreased appetite,
  • stomach pain,
  • restlessness,
  • anorexia,
  • insomnia,
  • strange dreams [40].

Drug testing

Cannabis and its active ingredient THC is tested for in most drug tests. After one-off or occasional use its break-down products or metabolites can be detected between 3 - 5 days after use. However, THC can be detected in a chronic user up to 12 weeks after use although the average is 25 - 27 days.

Cannabis is highly detectable a long time after use because THC lingers in the fatty tissues of the body and leaks steadily into the blood and then the urine over weeks. It is difficult to determine exactly how long it will take the THC to leave your body. It depends on your metabolism, how much you ingested and how often you used weed or hash [35].

Testing for marijuana and hashish use

Testing for the presence of THC is probably the most common drug test ordered. In most cases, a urine test is used for this purpose.

If the employer, court or other entity requesting the test has hired an agency to conduct the procedure, the first step in the process is to have the individual being tested go to a testing facility. He or she will be asked to remove their street clothing and put on a hospital gown. The idea behind this procedure is to minimise the chances of tampering with the sample.

The individual being tested may be asked to provide the sample in a dry room, which doesn't include any taps or sources of water. If a restroom is used for the sample collection, the water to the taps may be shut off at the main valve to prevent the subject attempting to dilute the sample with water. As an added precaution, coloured water may be added to the toilet.

Once the sample has been obtained, it is sent to a laboratory for analysis. In the U.S., federal guidelines are used to determine whether this initial screening is positive or negative. A negative test result doesn't necessarily mean that no trace of the substance was found in the subject's sample. It only means the level detected was below the cutoff as set by the government as being high enough to be considered positive [35].

Positive marijuana screening by usage frequency
Usage frequency Estimated detection length
Usage at 1 time only 5 - 8 days
Usage at 2 - 4 times per month 11 - 18 days
Usage at 2 - 4 times per week 23 - 35 days
Usage at 5 - 6 times per week 33 - 48 days
Daily usage 49 - 63 days [35].

Pot Testing Cutoff Levels

When drug tests are conducted, the unit of measurement is in nanograms per milliliter. When a urine sample is analysed, a positive test is one where the subject had a level of 50 ng/ml of urine. If a person has a positive test reading, a follow-up test will be conducted to confirm the finding. For the follow-up test, a positive result is one where the level of THC in the subject's sample is 15 ng/ml. These are very small amounts, and it is possible for a person who uses marijuana on an occasional basis to test positive for drugs.

False positives have been known to be triggered by consuming hemp-seed bars and other products, although the more detailed, more expensive gas chromatography-mass spectrometer (GCMS) test can tell the difference [35].

Second Hand Marijuana Smoke Positive Tests

In rare circumstances, passive smoking can cause false positives in urine tests, up to 4 days after exposure, although those who passively smoke have noticeably less concentrations in their urine.

There is some controversy over whether the cut-off levels used to detect cannabis in blood and urine tests is too low, leading to a high degree of false positives, especially from second-hand smoke. If you feel your drug test is false due to passive smoking, then you may be able to demand that the threshold of your test be increased 65 ng/ml, not the 15 ng/ml of many laboratories. The higher level is thought to distinguish between active and passive smoking [35].

Single use

  • blood - 1 - 3 days,
  • saliva - 12 - 24 hours,
  • urine - 1 - 3 days,
  • hair - 0 - 90 days [14].

Regular use

  • blood - 1 - 2 weeks,
  • saliva - 15 - 50 days,
  • urine - 15 - 50 days,
  • hair - 0 - 90 days [14].

Oral single use


Cannabis is illegal to possess and cultivate in most countries. However, recent research into its medical benefits have revealed it is a relatively benign and mostly harmless substance. Many countries, including the UK, Portugal and Canada, are re-evaluating the plant's legal status [35].

Legal status of marijuana in the United States

Cannabis remains a Schedule I drug in the United States, along with LSD and heroin, carrying the severest federal penalties for possession and supply [35]. A person who is found guilty of possessing more than 1,000 kilograms or more of marijuana or over 1,000 pot plants is subject to the following penalties -

  • Imprisonment for a period of 10 years to life; if a death or serious injury results, the sentence increases to 20 years to life.
  • A fine of up to $4 million for an individual; up to $10 million if the defendant is someone other than an individual [35].

If the defendant had been previously convicted of a felony, the penalty for this offense is 20 years to life. If death or a serious injury resulted from the distribution of the drug, the defendant may be sentenced to life in prison. The fines that may be imposed double to $8 million for an individual and $20 million where the defendant is not an individual [35].

When a defendant is convicted of possession of 100 kg of marijuana or 100 pot plants, he or she may be sentenced to the following punishment -

  • Imprisonment for between 5--40 years; life in prison if the drugs were responsible for death or a serious injury.
  • Fine of up to $2 million for an individual; up to $5 million where the defendant is a non-individual.
  • Fines double to $4 million and $10 million, respectively, in a case where a death or serious bodily injury occurs [35].

A person who is convicted of this type of offense cannot be granted probation or have his or her sentence suspended. Parole is not an option for these offenders, as well. However, people's opinions are changing, and many states have decriminalised pot or have allowed medical marijuana usage [35].

Legal status of marijuana in the UK

On January 29, 2004, cannabis was reclassified from a class B to a Class C drug. Class C is reserved for substances with an accepted medical use, such as steroids, anti-depressants, and some tranquillizers.

Five years later, cannabis was reclassified as a Class B substance on January 26, 2009.

Note: it's illegal to possess or cultivate the plants. However, if you're caught with cannabis, police can give you an official warning, rather than cautioning or charging you with an offense [35].

You can be arrested if -

  • You are publicly smoking.
  • You've previously offended or been given a warning.
  • You are aged 17 or under.
  • You are close to schools or other 'youth premises' [35].

The maximum penalty for possession is five years, while those convicted of supplying cannabis can face up to 14 years in prison [35].

  • Cannabis is a Class B drug - it's illegal to have for yourself, give away or sell.
  • Possession is illegal whatever you're using it for, including pain relief. The penalty is up to five years in jail.
  • Supplying someone else can get you fourteen years and an unlimited fine.
  • Supplying your mates, even if you give it away, is also considered 'supplying' under the law [12].

What if you're caught with cannabis?

If the Police catch you with cannabis, they'll always take some action. This could be a warning, a reprimand, a formal caution, a fixed penalty or an arrest and possible conviction.

A conviction for a drug-related offence could have a pretty serious impact. It can stop you visiting certain countries - for example the United States - and limit the types of jobs you can apply for [12].

Did you know?

  • Like drinking and driving, driving when high is illegal - and you can still be unfit to drive the day after smoking cannabis. You can get a heavy fine, be disqualified from driving or even go to prison.
  • Allowing other people to supply drugs in your house or any other premises is illegal. If the police catch people supplying illegal drugs in a club they can potentially prosecute the landlord, club owner or any person concerned in the management of the premises [12].

Legal status of marijuana in Canada

In Canada, marijuana possession and distribution falls under the provisions of the Controlled Drugs and Substances Act [35]. Possession of a small amount of marijuana (up to 30 grams) or hashish (1 gram or less) means the accused is subject to the following penalties -

  • Six months in jail, or
  • $1,000 fine [35].

For possession of a larger amount of weed, the penalties for a first offense are the same as listed above for a first offense [35]. For a second or subsequent offense, the penalties increase to the following levels -

  • One year in jail, or
  • $2,000 fine [35].

The judge hearing the case also has the option of imposing a sentence of a fine and imprisonment if he or she deems that it is appropriate [35].

Mixing with other drugs

Users contend that cannabis mixes well with other drugs. But while there are arguments that little or no major health risks are associated with using it, we recommend that you do not use cannabis and visit our cannabis effects section to learn why. If you are in the company of individuals using cannabis or plan to use yourself, be aware of how cannabis combines with other substances so that your risk of becoming a statistic is lessened. Again, the best choice is not using and avoidance of those who do.

Please note that there have been very few scientific studies into the effects of combining psychoactive drugs. The information presented here is anecdotal. It is based on the subjective reports of experienced users. Different people will respond differently to different drugs and drug combination. The effects may be different or dangerous for you. Know your body [35].

  • alcohol combined with marijuana - makes both drugs stronger; manageable at low doses, but can cause vomiting, dizziness, and increased paranoia with large amounts of both,
  • amphetamines combined with marijuana - can take the edge off the harsh speed buzz,
  • cocaine combined with marijuana - (uppers and downers) but can help modulate the grinding intensity of coke,
  • ecstasy combined with marijuana - extends and expands the experience of ecstasy; used to help bring on the high, it mellows the intense rushes and helps with the come-down; makes the ecstasy more psychedelic,
  • heroin combined with marijuana - users report complimentary effects,
  • ketamine combined with marijuana - no reported problems; Ketamine, however, amplifies certain cannabis effects (especially closed eye visuals and mind tunnels),
  • LSD combined with marijuana - dulls the experience in the come-up; heightens the peak; brings back the effect during comedown,
  • mushrooms combined with marijuana - same effects as a marijuana-LSD combination; can increase weirdness of the experience,
  • tobacco combined with marijuana - is a nasty drug [35].
  • marijuana + alcohol - nausea, vomiting, panic, anxiety and paranoia [9].
  • mixing cannabis with alcohol can have particularly serious consequences - the accident rate is 16 times higher than for cannabis or alcohol alone [12].

Sometimes people use cannabis (and other drugs) in the belief that it will help them cope better with their problems and feelings. Using cannabis in this way, however, can cause those problems to become more severe and difficult to manage in the long-term [41].

The effects of cannabis on mental health

Cannabis has a range of mental health effects on people. Some people experience very unpleasant psychological effects when they use cannabis, such as severe anxiety or panic reactions. At high doses users may hear voices or see/taste/smell things that are not really there (hallucinations), or have beliefs that are not true (delusions). These symptoms are more likely to be felt by people who are not used to the effects of cannabis or who have smoked more than they usually do. These experiences do not usually last after the effects of the cannabis wear off, but can be very frightening, and may be enough to put some people off using the drug again.

Some people appear to be more vulnerable to the mental health effects of cannabis than others, particularly younger people and those with a family history of mental health problems. Doctors prescribe medication for depression, psychosis, bipolar affective disorder or schizophrenia to bring relief from the unpleasant symptoms that a patient may be experiencing. If that person continues to use cannabis while taking prescribed medications, unknown reactions can occur, which may make their condition worse. It also makes it very difficult for their doctor to prescribe the correct drug at the appropriate dose to improve their symptoms, as well as increasing the risk of non-compliance with medication regimes. Furthermore, cannabis use can make symptoms of mental health conditions such as schizophrenia worse, if people diagnosed with this condition use the drug [41].

Mixing cannabis with antidepressant medication

People who have been diagnosed with depression can be prescribed antidepressants [41]. There are four main groups of antidepressants and the commonly used medications are listed with brand examples -

  • Tricyclics - nortriptyline (Allegron), clomipramine (Anafranil), amitriptyline (Tryptanol), imipramine (Tofranil), dosulepin (Prothiaden)
  • Selective Serotonin Reuptake Inhibitors (SSRIs) - sertraline (Zoloft), paroxetine (Aropax), citalopram (Cipramil), fluoxetine (Prozac), fluvoxamine (Luvox)
  • Monoamine Oxidase Inhibitors (MAOIs) - moclobemide (Aurorix) phenelzine (Nardil), tranylcypromine (Parnate)
  • Newer antidepressants - mirtazapine (Avanza), venlafaxine (Efexor) and reboxetine (Edronax) [41].

Very little research has been conducted on the effects of using cannabis while taking prescribed antidepressant medication [41]. The side-effects of antidepressants can be similar to those produced by cannabis use, and these include the following -

  • tachycardia,
  • dizziness,
  • anxiety,
  • panic,
  • drowsiness,
  • nausea,
  • confusion [41].

Using cannabis while taking prescribed antidepressants can intensify any or all of these side-effects and make a person feel worse [41].

Mixing cannabis with antipsychotic medication

Antipsychotic medication is prescribed for people who have had psychotic episodes and have been diagnosed with schizophrenia [41]. Common antipsychotic medications with examples of brand names used in Australia are -

  • Antipsychotic Medications (older medications) - chlorpromazine HCl (Largactil), haloperidol (Serenance, Haldol), trifluoperazine (Stelazine), flupenthixol (Fluanxol), zuclopenthixol (Clopixol)
  • Atypical Antipsychotic Medications (newer medications) - olanzapine (Zyprexa), risperidone (Risperdal), clozapine (Clozaril, Clopine), quetiapine (Seroquel), ziprasidone (Geodon, Zeldox), amisulpride (Solian), aripiprazole (Abilify), paliperidone (Invega) [41].

Antipsychotic medications are most effective in treating the hallucinations and delusions associated with schizophrenia and other psychotic disorders, however they may not help with other symptoms such as motivation and emotional responsiveness. Because of this, people with schizophrenia can experience depression, which may also need to be treated. All these symptoms are made worse if cannabis is being used.

Research suggests that counselling can greatly improve the chances of a person giving up or cutting down their cannabis use while taking medication.

While there is very little research on the effects of the combination of cannabis and antipsychotic medications, there is evidence that suggests that those people prescribed clozapine experience less craving for cannabis than those who are prescribed risperidone or quetiapine. Further research into this area is being conducted [41].

Quick tips

The medications prescribed by a doctor are to improve the health and wellbeing of the patient. Using cannabis at the same time, will make the symptoms worse and the medications less effective [41]. If you use cannabis regularly and take prescribed medications, or know someone who does, the following things may help -

  • make sure the prescribing doctor is aware of the cannabis use and how much is being used,
  • see a specialised counsellor - it greatly improves the chances of decreasing or stopping cannabis use while taking medication,
  • give the medication a chance - it can take up to six weeks for antidepressant and anti-psychotic medications to take effect,
  • be aware that if cannabis is taken with antidepressants, it can produce similar side-effects and intensify reactions, such as rapid heartbeat, dizziness, anxiety, nausea and sweating,
  • do not take cannabis with tricyclic antidepressants because this increases the risk of rapid heartbeat and other side-effects such as confusion, restlessness, mood swings and hallucinations,
  • do not take cannabis with MAOI antidepressants as it is thought to affect the way the medicine works,
  • do not use cannabis with newer antidepressants as there is very little published research about possible reactions,
  • there has been limited research on taking cannabis with SSRI antidepressants. However, the limited information available suggests that SSRIs may be a safer choice of antidepressant if you use cannabis. Make sure you speak to your doctor for further information,
  • avoid using cannabis if you are prescribed antipsychotic medications,
  • if there are any problems experienced while being on medication and using cannabis see a doctor or other healthcare professional [41].

What about mixing cannabis and alcohol?

Not counting tobacco, the most common form of polydrug use is alcohol and cannabis. When people mix cannabis and alcohol together at one time, the results can be unpredictable. The effects of either drug may be more powerful, or the combination may produce different and unpredictable reactions [41].

Harm reduction

Here are some harm reduction tips for cannabis -

  • reduce or cut out tobacco as a mixing agent,
  • avoid holding smoke in your lungs. It increases intake of tar without getting you any more stoned,
  • don't inhale too deeply - it will not get you more stoned it just increases the deposition of waste in your lungs. The stuff that gets you stoned gets absorbed in the upper airways,
  • smoking bongs or water pipes filters out more THC than tar and you lose lots in side stream smoke,
  • remove stems, seeds and leaf (unless you are using leaf instead of tobacco),
  • don't use a cigarette filter as it will filter out THC (reducing the effect) as well as tar and may lead you to smoking more or more deeply,
  • use a plain cardboard roach and avoid printed/plastic covered materials,
  • treat your paraphernalia with pride. Keep your pipes and bongs clean and avoid plastic bottles, pipes, etc as can increase toxic fumes,
  • if you have to smoke and are worried about cancer or lung disease try a vaporiser which avoids combustion and reduces the release and deposition of tar and carcinogens,
  • wait till you've seen to all life's daily necessities (fed kids, cleaned up, done any important tasks and don't need to drive) before you start smoking or at least until your brain has stopped developing (about 20 years old) [8].
  • the responsible cannabis user does not operate a motor vehicle or other dangerous machinery impaired by cannabis. Although cannabis is said by most experts to be safer than alcohol and many prescription drugs with motorists, public safety demands that impaired drivers be taken off the road and that objective measures of impairment be developed and used, rather than chemical testing.
  • cannabis consumption is for adults only. Many things and activities are suitable for young people, but others absolutely are not. Children do not drive cars, enter into contracts or marry, and they must not use drugs.
  • the responsible cannabis user will carefully consider his/her setting and regulate use accordingly. The responsible cannabis consumer will be vigilant as to conditions - time, place, mood, etc. - and does not hesitate to say 'no' when those conditions are not conducive to a safe, pleasant and/or productive experience.
  • the responsible cannabis user does not violate the rights of others, observes accepted standards of courtesy and public propriety, and respects the preferences of those who wish to avoid cannabis entirely. Regardless of the legal status of cannabis, responsible users will adhere to emerging tobacco smoking protocols in public and private places.
  • recommended time (pauses) between using the substance.
  • use of cannabis, to the extent that it impairs health, personal development or achievement, is abuse and should be resisted by responsible cannabis users. Abuse means harm. Some cannabis use is harmful; most is not. That which is harmful should be discouraged; that which is not need not be [14].
  • avoid using printed card for roaches if smoking. Inhaling ink could cause damage to your lungs,
  • use short puffs when inhaling. The active ingredients THC and CBD enter the blood stream in a few seconds so holding in smoke doesn't increase the effects but it can do more damage to your lungs,
  • use low strength tobacco if smoking,
  • using a vaporiser, although costly, allows you to 'smoke' cannabis without the dangers of smoke. Flavours will be more intense too,
  • know your source! Avoid cheap resins which can contain henna, plastic and other fillers,
  • if eating, dose carefully as effects can take a while to come on. Wait at least 1 hour before re-dosing to ensure there are no bad effects,
  • avoid mixing with other drugs, medicines and alcohol [42].

Cannabis as a medicine

There is a considerable amount of research being done in the UK at the moment, looking at the possible benefits of cannabis for the treatment of muscular and somatic pain, and the symptoms of multiple sclerosis (MS) and wasting diseases, amongst others. In June 2010, GW pharmaceuticals announced that clinical trials have shown that 'Sativex' (which is sprayed under the tongue), reduces spasticity in multiple sclerosis patients who do not respond adequately to existing therapies. A licence to prescribe this drug is available via the UK Regular. Sativex uses a ratio of 1:1 THC/CBD. It was granted a UK licence in 2011, but it is extremely difficult to access the medicine from practitioners, in part due to the cost.

There is a strong research base to support the use of cannabis to control nausea. More recent research supports the beneficial effects of cannabis and THC-based medications in the treatment of symptoms arising from conditions such as MS and AIDS; for example, as an appetite stimulant to combat physical wasting. A recent study showed that ∆9 THC and other cannabinoids exert antidepressant-like actions, and thus may contribute to the overall mood-elevating properties of cannabis.

Smoking is by far the most common method of taking cannabis. Like tobacco, cannabis smoke contains toxins that are known to be hazardous to the respiratory system. These toxins are essentially a by-product of combustion, separate from the THC and other pharmaceutically active components of cannabis. Although there is no proof that smoking cannabis (without tobacco) causes cancer, heavy users have been shown to be more at risk of bronchitis and respiratory infections [8].

Mental Health

There have been a number of concerns raised in the press recently regarding cannabis smoking and its impact on health and increases in treatment-seeking for cannabis-related problems linked to purported increases in cannabis potency.

Most people who use cannabis will never experience mental health problems as a result. However, it appears indisputable that cannabis does have a detrimental effect on the mental health of a minority of individuals. It is likely that cannabis exposure is a component cause that interacts with other factors to cause schizophrenia or a psychotic disorder, but is neither necessary nor sufficient to do so alone.

The risks seem to be highest for young people, those who use cannabis heavily and those who suffer from, or have a vulnerability to, mental illness (e.g. family history of psychotic disorders).

There is often a time lapse between cannabis use and the onset of psychiatric disorders. Furthermore, other factors such as general health, family and social relations, education and employment are difficult to exclude. Genetic predisposition is another complicating factor. It is also difficult to isolate the effects of cannabis in circumstances where it is often used in conjunction with other substances [8].



In recent years, the potency of cannabis in the UK has been increasing, i.e. the concentration of the major psychoactive cannabinoid in cannabis, THC, has increased. Within the same time-frame, the number of young people seeking treatment for cannabis dependence has also increased [43], [44]. This upsurge is thought to be due to the rising THC levels.

At the same time as THC levels have risen, there has been a corresponding decrease in the amount of the primary non-psychoactive, and possibly protective, cannabinoid called CBD [45].

Cannabis users are advised to smoke varieties of cannabis that are high in CBD e.g. resin/hash and to avoid 'skunk'. If you don't have much experience with cannabis, you are more likely to get paranoia if the strain is low in CBD and high in THC [16].


It's very uncommon, but you might feel unwell after consuming cannabis. It can happen to anyone, although it is more common in first-time users. Surprisingly, it can occur with low or high doses and with a strain you have tried before. When this happens, people generally feel nausea, paranoia and look pale (hence, 'whitey') [16].

To help yourself or a friend consider doing the following -

  • Drink some water and consume sugar. Be careful with overeating or drinking too much: take water in short sips and eat small bites, take your time to chew and swallow.
  • Lie down and take deep breathes. Slow down your breath rate.
  • To help someone who is whiteying: talk slowly and calmly to the person. Find out if he/she needs conversation and attention or prefers silence and some time on their own. Provide them with water and something to eat. Help them breathe deeply and at a constant pace.
  • Take it easy for the rest of the day and rest. You should not consume more drugs even if you feel full of energy again, as your body will be less well-equipped to process them [16].



Some people observe feeling 'hungover' after consuming marijuana, others don't.

You may experience some of the following -

  • congestion,
  • dehydration,
  • dry itchy eyes,
  • feeling of being in slow motion,
  • grogginess or spaciness,
  • headache,
  • lethargy,
  • mild nausea [16].

The best advice we can give to reduce hangovers is to drink plenty of water and get enough sleep! [16].

Health implications

Smoking cannabis, especially with tobacco, carries health risks. These relate to lung damage, especially bronchial problems, and an increased risk of lung and throat cancers. These problems are not removed by smoking without tobacco, and some studies indicated that cannabis smoke is more carcinogenic than tobacco. Certainly, people smoking cannabis tend to hold the smoke in their lungs longer, and this means more damage can occur.

Using cannabis regularly can cause short-term memory loss, and apathy or listlessness. While it is not physically addictive, people can and do become psychologically dependent, and find stopping smoking difficult.

Many sources argue that cannabis is linked to the development of mental health problems, most notably cannabis psychosis. It is also claimed that cannabis can trigger underlying mental health problems. These various arguments are hotly disputed by pro and anti cannabis lobbyists. However, there is increasing evidence that the heavy use of strong cannabis amongst young people increases the risk of serious mental illness [10].


There are many different methods through which users smoke. Marijuana that has been rolled into cigarette paper is referred to as a 'joint', and can be rolled by hand or by a rolling machine. A 'blunt' simply refers to a common cigar that is split open, emptied of tobacco, and refilled and rolled with marijuana. This term comes from Phillies Blunts, but other, similar, types of cigars are also commonly used, including White Owls, El-Productos, Backwoods, Garcia-Vegas, and Dutchmasters. Users also commonly smoke marijuana through hand-pipes made of glass or wood, and through waterpipes (bongs) made of glass or plastic. Water pipes allow the smoke to be filtered and cooled prior to inhalation, providing the user with larger, cleaner hits. Also, vaporisers supply another way of smoking marijuana, in which the drug is heated enough to vaporise the plant and release the THC, without the user having to inhale large amounts of smoke [3].

Tobacco, cigarette papers (rizlas or skins), cardboard (used for the tip, known as a roach), pipes or bongs [7].


Marijuana first became popular in the United States with Mexican immigrants in the 1920's and was quickly adopted by those in the jazz community. Later, the Great Depression of the 1930's led to a growing hostility toward the increase in marijuana use that was linked to immigration. The Marihuana Tax Act of 1937 placed control of the Cannabis plant into the hands of the federal government, which released very exaggerated portrayals of marijuana's effects (i.e. 'Reefer Madness') and made the drug illegal. These stories, paired with the ban on private use, kept marijuana use fairly uncommon until the 1960's. After the 'hippie' counterculture rediscovered marijuana in the 1960's, demand for, and use of, the substance grew until about 1978, when the favourable attitude toward the substance reached a peak. Since then, public attitudes have varied greatly from complete intolerance to ideas of legalisation. In 1970, marijuana was listed as a Schedule I drug where it still remains today; however, the medical use of marijuana has been a hot topic for the last decade, along with the advent of synthetic forms of THC (i.e., Marinol) [3].

Its use not unlike today can be divided into recreational, ritual and medicinal.

Evidence of the inhalation of cannabis smoke can be found in the 3rd millennium BC, as indicated by charred cannabis seeds found in a central European burial site.

It is well documented that cannabis leaf fragments and seeds were found next to a 2,500 year old preserved body of a shaman in China.

Cannabis is also known to have been used by the ancient Hindus of India and Nepal thousands of years ago.

The most likely etymological root of 'Cannabis' was also known to the ancient Assyrians who discovered its psychoactive properties, probably from their border contact with the Indians, using it in some religious ceremonies. They called it qunubu (meaning 'way to produce smoke'). Herodotus notes that the Scythians, a feared tribal group of horse archers, used to carry and burn the leaves and seeds which they burnt in fires and funeral pyres.

Cannabis was used medicinally across the Arabic world in pre-Roman and Roman times.

In the 11th century, it is reported, probably without a shred of truth (at least judging from the effects mentioned in the tale), that the word assassin comes from the Arabic word haschishin for hashish user.

The story is that al-Hassan ibn-al-Sabbah used hashish to enlist the aid of young men into his private army known as assassins (aschishin - or follower of Hassan). One of the primary sources for this information comes from the writings of Marco Polo who visited the area 150 years after the reign of Al-Hassan. The story is repeated widely in the 20th century work of William Burroughs, but probably because of its potency as a homo-erotic fantasy and the theme of control is a constant in Burroughs' own work.

'The Old Man kept at his court such boys of twelve years old as seemed to him destined to become courageous men. When the Old Man sent them into the garden in groups of four, ten or twenty, he gave them hashish to drink. They slept for three days, then they were carried sleeping into the garden where he had them awakened. When these young men woke, and found themselves in the garden with all these marvellous things, they truly believed themselves to be in paradise. And these damsels were always with them in songs and great entertainments; they received everything they asked for, so that they would never have left that garden of their own will.

When the Old Man wished to kill someone, he would take a young man and tell him they could return to Paradise if they entered his service and followed his instructions or died in his service'.

The website Erowid sums up; 'Hassan, in fact, was a hashish prohibitionist. He argued that the Koran's ban on alcohol was a ban on all intoxicants, so his assassins were drug free terrorists'.

You can draw your own conclusions.

The story of Shakespeare's (alleged) pipes containing traces of cannabis is well known and some scholars have sought to find a direct reference to cannabis in the sonnets, particularly number 17. It does however imply that in certain artistic circles, cannabis was not unknown, another nice commonality with our own age.

Cannabis appears in a number of major European works of art in the 17 - 18th century, for example in the sailor's section of 'The Count of Monte Christo' (although the section was heavily abridged in many versions). Napoleon banned the use of hashish among soldiers, with whom it was becoming popular during his ill-fated Egyptian campaign. In fact, the pharmacy records from Balmoral under the reign of Victoria, a hundred years later, were twice prevented from public disclosure due to the significant quantities of drugs, including tincture of cannabis that the Queen used, ostensibly for cramps, but also possibly for solace after the death of her husband. Traditionally, British drug laws have been among the most liberal in terms of the state not interfering with the adults decision to use drugs, but the Amendment to Dangerous Drugs Act 1920 made possession of cannabis an offence, albeit one that was not too enthusiastically applied, particularly among the upper classes.

Cannabis was criminalised in various countries beginning in the early 20th century. In the United States, the first restrictions for sale of cannabis came in 1906 and in the United Kingdom in the 1920's although the drug was available on prescription here. In 1925 a compromise was made at an international conference in The Hague about the International Opium Convention that banned exportation of 'Indian hemp' to countries that had prohibited its use, and requiring importing countries to issue certificates approving the importation and stating that the shipment was required 'exclusively for medical or scientific purposes'. It also required parties to 'exercise an effective control of such a nature as to prevent the illicit international traffic in Indian hemp and especially in the resin'.

In the United States in 1937, the Marihuana Tax Act was passed, and prohibited the production of hemp in addition to cannabis. The reasons that hemp was also included in this law are complicated. Racism played a part, as the drug was seen as a non-White Anglo Saxon vice. The alcohol lobby recovering from their own prohibition had an influence, as did significant vested interests in timber that saw hemp as a threat to paper in the news industry and William. R. Hearst ('Citizen Kane') consequently believed that his extensive timber holdings were under threat. A new synthetic fibre, nylon, was being heavily promoted and it is believed that the replacement of hemp, was integral to the new product's success.

After the repeal of alcohol prohibition in 1933, Harry Anslinger, of the federal Bureau of Narcotics, turned his attention to pot. He told of sensational crimes reportedly committed by marijuana addicts. No one knows, when he places a marijuana cigarette to his lips, whether he will become a philosopher, a joyous reveller in a musical heaven, a mad insensate, a calm philosopher, or a murderer, he wrote in a 1937 magazine article called 'Marijuana: Assassin of Youth'. Note the return of 'Assassin'.

This hysteria was captured in the propaganda films of the time - most famously, 'Reefer Madness', which depicted young adults descending into violence and insanity after smoking marijuana. The movie found little audience upon its release in 1936 but has since become a cult classic.

As the conformity of the post-war era took hold, getting high on 'tea' (hip-speak for marijuana) and other drugs emerged as a symbol of the counter-culture revolution, with Jazz musicians and the 'beatniks' as the cool face of stoned.

The Vietnam war polarised America beyond the pro or anti war debate. The widespread, open use of marijuana by hippies and war protesters from San Francisco to Woodstock exposed the exaggerated claims so many had made about marijuana's relation to violence. Around this time, cannabis becomes widely used, (if it had ever ceased?) by many people in the creative industries, art and music scene and at colleges, art-schools and universities across the UK. The popularity of Reggae music (and later on Hip-Hop) further enshrined the idea that cannabis is a harmless recreational drug which continued through the late 1970's and early 80's and the drug, was enthusiastically embraced, along with ecstasy by the 'rave generation'.

Across this period, cannabis use becomes part of the not paticularly hidden mainstream of recreational substance use. Drug testing companies have also noted the ubiquity of cannabis postives in patients treated for other drugs, such as heroin.

'Cesamet' (THC in a capsule) was also trialled as an appetite stimulant among HIV positive patients in London and the therapeutic use of cannabis in the UK begins to be taken seriously by medical researchers. A trial for MS patients was piloted at St Thomas' Hospital, using the THC only variant of 'Sativex' in the late 1990's.'The Brixton experiment' (an area of South London which has a high percentage of 2nd/3rd generation British people of Afro-Caribbean descent) permitted the use of cannabis (unless 'blatant' or under-age) which translated the existing de facto ubiquitous local use of the drug to a temporary de jure. There was a widespread media backlash, but as young people don't read the Daily Mail or Express, they were not greatly bothered, although the experiment was phased out in 2002. While the debate about potential developmental/psychological problems associated with cannabis endures, the medical benefits, particularly in analgesia have become established. Users had been extolling the potential benefits for what did we say earlier? About 3000 years [1]!

The medicinal properties of cannabis were first recorded in 2737 BC in Shen Nung dynasty China, and it was widely used in Victorian Britain as a patent medicine and tonic. Its psychoactive properties were known to the Scythians in Ancient Greece, but were first reported in Europe following Napoleon's invasion of Egypt, but use was confined to bohemian groups such as writers and Jazz musician until the social revolution of the 1960's [13].

See also bongs


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