What is cannabis?
Cannabis is a drug produced from the Cannabis sativa (commonly known as hemp) or Cannabis indica plant, which is related to nettles and hops. It’s believed to have originated in the mountainous regions of India, and grows wild in many parts of the world.
The plant contains more than 400 chemicals, including cannabidiolic acid, an antibiotic with similar properties to penicillin. The different chemical derivatives of the plant can be used for medicinal or recreational purposes.
The recreational drug cannabis comes in many forms – herbal (dried plant material), resin, powder and oil – and is known by many slang terms, including weed, pot, grass and hash. In the UK, cannabis is a Class B illegal drug.
Effects and uses of cannabis
Cannabis is most widely used as a illegal street drug for its relaxing properties. It is usually rolled into a cigarette known as a joint, but can also be smoked in a pipe, brewed as a tea or mixed with food.
The main active ingredient in cannabis is tetrahydrocannabino (THC). One type, skunk, can be particularly potent as it contains two to three time as much THC as other types.
Cannabis acts as a mild sedative, leaving most people feeling relaxed, chilled out or just sleepy. It also:
- Has mild hallucinogenic effects, causing a distortion of reality
- Makes some people become more animated
- Releases inhibitions, making people talkative or giggly
- Can cause nausea in some people (despite the fact that cannabis can have an anti-nausea effect), while it quite often makes others feel hungry
Medical uses of cannabis
Cannabis or its derivatives may also be used as a medical treatment. There is some scientific evidence to suggest it may be useful in a wide range of conditions. But the complex nature of the substances contained within the plant makes it difficult for medical research to establish the safety or efficacy in its natural form, so its effects are far from proven or well-understood. As scientists are interested in the possible therapeutic properties of cannabis, they are working to gradually identify the active chemicals within (these chemicals are known collectively as cannabinoids). Cannabinoids activate a number of receptors throughout the body but especially in the central nervous system and the immune system, and so may have several effects.
Wide-scale trials testing the safety and efficacy of these cannabis extracts (or synthetic forms of them) are currently underway in the UK and elsewhere. So far there has been interest in the use of cannabinoids in nausea and vomiting, appetite, control of cancer symptoms, pain, anxiety and muscle spasticity.
For instance, cannabis appears to be able to help reduce the side effects of chemotherapy treatment, although not more so than other already established medications. The drugs used to treat cancer are among the most powerful, and most toxic, used in medicine. They produce unpleasant side effects, such as days or weeks of vomiting and nausea after each treatment. Some cannabinoids relieve nausea and allow patients to eat and live normally.
Cannabis extracts also seem to benefit people suffering from multiple sclerosis (MS), by reducing muscle spasticity and so increasing their ability to stay independent. The first cannabinoid medicine derived from whole plant extracts (from the cannabis sativa plant) came into use in the UK in 2010 for people with moderate to severe spasticity in MS who haven’t responded to other treatments. Unlike recreational cannabis, this treatment doesn’t cause euphoria – less than 3% of those in trials for the drug said it changed their mood.
Claims have also been made for its use in treating:
- Parkinson’s disease
- Alzheimer’s disease
Risks of cannabis
There’s increasing evidence that cannabis use is linked to a number of health risks. It damages the ability to concentrate, decreases motivation and more than occasional use in teenagers can affect psychological development. Users can become anxious, suspicious and even paranoid. Heavy use increases the risk of serious psychiatric illness.
Users of skunk, a stronger and increasingly more available form of cannabis, are seven times more likely to develop a psychotic illness, such as schizophrenia, than people not using cannabis or using the more traditional forms. Cannabis also interferes with coordination, causing problems with balance, walking and driving.
There are other side effects of the drug, but they vary considerably and are less predictable, partly because cannabis has more than 400 active ingredients. They may include effects on the heart, such as increased heart rate and blood pressure, and damage to fertility. People who smoke cannabis are also exposed to the toxic chemicals in tobacco smoke.
People may become dependent on cannabis and find it difficult to stop using it, experiencing unpleasant withdrawal symptoms if they do stop such as cravings, agitation, mood changes, sleep problems, appetite disturbance and other symptoms.
The debate over the use of cannabis in medicine is highly controversial and emotive. Supporters of the drug claim it has wide-ranging benefits, but opponents say it is a potentially dangerous substance that can actually damage health.
Cannabis and the law
The use of cannabis remains illegal (except for prescribed cannabinoids as described above). It is a Class B drug. As a result, the penalties for getting caught with cannabis, especially on repeated occasions, can be severe. The maximum penalty for possession is 5 years in prison and for supplying the drug, 14 years, although an initial reprimand or penalty fine may be given for first-time offenders.
A report by the House of Lords Science and Technology Committee in 1997 recommended the use of cannabis for medicinal purposes. However, the British Medical Association (BMA) did not give the report tis full support and believes only cannabinoids – carefully identified chemical derivatives of the cannabis plant – should be used in medicine.
Advice and support
Occasional users of cannabis may be able to give it up, although they may find it harder to give up the general smoking habit. However, heavier users may need expert help to stop. Talk to your GP or local community drug agency or clinic.
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