Warning over dope danger

By JEREMY LAURANCE

The increasing use of cannabis by adolescents is threatening the mental health of a generation because of the drug's unrecognised capacity to trigger psychosis, a leading psychiatrist has warned.

Professor Robin Murray, of the Institute of Psychiatry in London, says growing evidence linking cannabis with mental disorder has failed to curb use of the drug.

One study suggested cannabis users were seven times more likely to develop mental problems.

"In the last 18 months a number of studies have confirmed that cannabis consumption acts to increase later risk of schizophrenia. This research must not be ignored," Professor Murray told the Royal College of Psychiatrists annual conference in Edinburgh.

As he delivered his warning, doctors at the annual conference of the British Medical Association in Torquay rejected by a large majority calls for cannabis and other recreational drugs to be legalised.

Connie Fozzard, 70, a retired surgeon from Cornwall, told the BMA conference that legalisation would help to cut crime.

"Prohibition does not work. Just look at the experience of the [United States] when they tried to ban alcohol.

"What arose out of that was Al Capone and armed gangs and that is what happening now in this country," she said.

But Professor Murray said research suggested cannabis might interact with a genetic vulnerability in some people, sufficient to push them over the edge.

His review of research in Sweden, Holland and New Zealand showed cannabis use was higher among psychotic patients than in the general population. It had been thought that patients took the drug to counter the negative symptoms of the illness, but Professor Murray said that had been ruled out by more recent research.

A Dutch study of 4000 people in the general population showed that those taking large amounts of cannabis were almost seven times more likely to have psychotic symptoms three years later.

Another study, in 1987, of 50,000 Swedish Army conscripts, found that those who admitted at age 18 to having taken cannabis more than 50 times were six times more likely to develop schizophrenia in the next 15 years.

A study in New Zealand found that those who used cannabis at 15 were 4 1/2 times more at risk of developing psychosis by the age of 26.

Professor Murray said the results held even when initial personality was taken into account.

He concluded that the impact of cannabis on the mental health of young people "may not be negligible" and that reducing use among the young "may help to avoid some cases of psychosis".

The findings come as the British Government prepares to downgrade cannabis from a Class B to a Class C drug next year, so that it attracts a lesser penalty for possession.

Most people caught in possession of a small amount will have the drugs confiscated and receive a reprimand or warning, the Home Office has said.

A Home Office spokesman said the aim was to free police time to concentrate on the more serious Class A drugs such as heroin.

"Even when it [cannabis] is reclassified it is still going to be an illegal drug. The whole point of reclassifying it is that it enables us to give a more credible message about the relative dangers of drugs."

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