|
Cannabis Campaigners' Guide News Database result:
|
|
UK: Q and A: Cannabis and mental health
BBC Online
Thursday 05 Jan 2006 Home Secretary Charles Clarke has said the government decision to downgrade cannabis has confused the public about the impact of the drug. The drug was downgraded from class B to class C two years ago. However, Mr Clarke is due to review that decision in light of fresh medical evidence. What is cannabis? A plant cultivated by humans for thousands of years. It contains chemicals called cannabinoids which are unique to the plant. These include a substance called delta-9-tetrahydrocannabinol (THC) which is believed to be largely responsible for the effects that the drug has on the brain. How is the drug used? It is usually smoked, but can also be eaten. When smoked THC is absorbed into the bloodstream and accumulates in the brain and other major organs. It can produce an effect on the brain within minutes. A proportion of the chemical will also linger in the body, and can produce subtle mental and physical effects over a long period. If the drug is eaten, less THC reaches the brain, and it takes longer to get there. What effect does the drug have? Cannabis produces a feeling of euphoria commonly known as a high. It may also trigger changes in perception. For instance, colours may seem brighter and more intense, and emotions may be heightened. However, there is strong evidence linking cannabis use to feelings of anxiety and panic. It is also associated with lethargy, loss of communication skills and a general lack of ambition. However, cannabis is not thought to affect memories which are already in place - only the ability to store new ones. Is there a link to mental illness? Research suggests that cannabis use can trigger symptoms of psychosis in some people. These can include hallucinations, fantasies, a feeling of loss of control, and a sense of feeling out of touch with your surroundings. What is not clear is whether psychotic symptoms are usually short-lived, or whether they are more long-term, and persist even when use of the drug is stopped. What about more serious problems? Many experts now believe that use of the drug can worsen symptoms in someone who already has schizophrenia, or manic depression associated with psychotic symptoms. It is thought that cannabis may act to switch on key genes related to such conditions in vulnerable people. However, evidence is beginning to emerge that long-term use of cannabis, particularly when use begins in early teenage years, can trigger schizophrenia in people who should be at no or low risk of the illness. A British Medical Journal study published last year concluded that cannabis use moderately increases the risk of psychotic symptoms in young people - but has a much stronger effect on those who have already demonstrated a predisposition to symptoms. What has the research found? A study by New Zealand researchers published last year concluded that smoking cannabis virtually doubles the risk of developing mental illnesses such as schizophrenia. Another, by Swedish researchers, suggested cannabis use increases the risk of schizophrenia by 30%. Separate research highlighted evidence that smoking cannabis as a teenager increases the odds of developing schizophrenia as an adult. A Danish study, published last month, found almost half of patients treated for a cannabis-related mental disorder go on to develop a schizophrenic illness. The mental health charity Mind reported that psychiatrists had seen an increase in numbers of people being hospitalised with psychotic episodes linked to cannabis use since the drug was downgraded in the UK in 2003. Is the drug getting stronger? Yes. In the 1960s the average cannabis 'joint' contained about 10mg of THC. Now a joint made of one of the most potent types may contain 150mg, or even more. Researchers are therefore concerned that much of the research into the effect of the drug may be out of date.
After you have finished reading this article you can click here to go back.
|
This page was created by the Cannabis Campaigners' Guide.
Feel free to link to this page!