CANNABIS LINK TO SCHIZOPHRENIA

Psychiatrists are calling for caution in the move towards licensing
cannabis-based medicines.

It follows research into a possible link between cannabis use and
schizophrenia.

Two recent studies have shown that heavy use of cannabis is associated with
a fourfold increased risk of developing the mental illness.

"There are some dangers to using high doses of cannabis that people need to
know about," said Dr Deepak Cyril D'Souza, Associate Professor of
Psychiatry at Yale University School of Medicine.

He said there was concern in the medical profession that people who smoke
large amounts of cannabis for a long period of time are at higher risk of
developing schizophrenia.

This needs to be kept in mind in the testing of new cannabis-based
medicines, he added.

He told BBC News Online: "We need to do some kind of study to establish the
psychiatric safety profile of these drugs."

Dr D'Souza presented new evidence on the link between cannabis and
schizophrenia at the Institute of Psychiatry at the Maudsley Hospital in
London.

His research suggests cannabis may induce psychosis by its action on
cannabinoid receptors in the brain.

He was speaking at the launch of the European Foundation for Psychiatry at
the Maudsley.

Secret Crop

Cannabis-based medicines could be available in the UK within a year
following promising results in clinical trials.

GW Pharmaceuticals, the company granted a government licence to carry out
tests on cannabis compounds, announced on Tuesday that advanced phase III
trials had been successfully completed.

The tests, the last stage of drug evaluation before approval, showed that
cannabis-based medicines can help to relieve symptoms of multiple sclerosis.

GW, which cultivates some 40,000 cannabis plants a year at a secret
location in the English countryside, plans to seek marketing approval from
Britain's Medicines Control Agency early next year.