Cannabis: Damages The Brain Or Relieves Pain?

Its effects are disputed, with some linking the drug to schizophrenia, while others say it is safer than alcohol.

Cannabis is the most widely-used illegal drug in Britain. Two million people smoke it, although the number of users is falling.

The main active chemical is tetrahydrocannabinol, or THC, which makes users more relaxed and can trigger hallucinations.

Skunk, now widely available, contains two or even three times more THC than street cannabis did 30 years ago.

And that has heightened the debate over the harms of the drug.

According to Professor David Nutt, the former chair of the Government's Advisory Council on the Misuse of Drugs, cannabis - even in its stronger form - is safer than

He opposed the upgrading of the drug from Class C to B, putting it on a par with amphetamines, arguing that the mental health risks were small.

He said the move was politically, rather than scientifically, motivated.

But according to the Royal College of Psychiatrists, children who start smoking cannabis before they turn 15 are four times more likely to develop a psychotic disorder by the age of 26.

It says three major studies have linked early use of the drug with schizophrenia.

People with a genetic susceptibility to psychotic illness - and those who use the drug more often - are more likely to suffer mental health effects.

According to the college, it believes teenagers are particularly vulnerable to cannabis because it affects the developing brain.

Cannabis also reduces motivation and can cause insomnia and nausea.

Some research has shown that skunk affects concentration and short-term memory.

There is also accumulating evidence that cannabis can have positive effects on some medical conditions.

Some patients use it to relieve pain, muscle contortions and chemotherapy-induced nausea.

However, the law in England and Wales does not recognise any therapeutic value and patients can be charged for possession.

In 2010, the UK medicines regulator approved a cannabis-based product called Sativex for spasticity caused by multiple sclerosis.

The oral spray delivers a regulated dose and has been shown to provide therapeutic benefits, without the negative effects on the brain.

http://news.sky.com 15/01/2014