STUDIES SHOW DAGGA INCREASES RISK OF SCHIZOPHRENIA, PSYCHIATRIST WARNS

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

Robin Murray, a professor at the Institute of Psychiatry here, said growing
evidence linking cannabis with mental disorder had failed to curb use of the
drug. One study suggested cannabis users were at seven times higher risk of
developing mental problems.

"In the past 18 months, a number of studies have confirmed that cannabis
consumption increases later risk of schizophrenia," he told the Royal
College of Psychiatrists annual conference in Edinburgh. "This research must
not be ignored."

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

Connie Fozzard, a retired surgeon, told the conference legalisation would
help to cut crime.

"Prohibition does not work," she said. "Just look at the experience of the
United States when it tried to ban alcohol. What arose out of that was Al
Capone and armed gangs - and that is what happening now in this country."

Speaking at the psychiatrists' conference in Edinburgh, 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 found cannabis use
was higher among psychotic patients than the broader population. It had been
thought that patients took the drug to counter the negative symptoms of the
illness, but Murray said this had been ruled out by more recent research. A
Dutch study of 4 000 people found that those taking large amounts of
cannabis were almost seven times more likely to have psychotic symptoms
three years later.

A study in 1987 of 50 000 Swedish conscripts found that those who admitted
at age 18 to having used cannabis on more than 50 occasions were six times
more likely to develop schizophrenia in the following 15 years.

Research in New Zealand found that those who used cannabis at age 15 were
four-and-a-half times at higher risk of developing psychosis by the age of
26.

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 there will be a lesser penalty
for possession. Most people caught in possession of a small amount will have
it confiscated and receive a reprimand or warning.

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