CANNABIS EFFECT ON MENTAL ILLNESS SLIGHT -- DOCTOR

Cannabis use has little effect on mental illness apart from a small group
of people suffering from schizophrenia or predisposed to it, a
parliamentary select committee was told yesterday.

Dr John Marks, who heads Capital Coast Health's drug and alcohol unit [sic;
he heads CCH's dual diagnosis unit], told the health select committee that
cannabis use caused no significant harm. The committee is holding an
inquiry into the mental health effects of cannabis.

Dr Marks, a member of the Drug Policy Forum Trust, a doctors' group that
supports decriminalising the drug, said cannabis use could aggravate the
condition of some people with schizophrenia -- about one in 10,000.

Dr Nick Judson, the Ministry of Health's deputy director of mental health,
said cannabis caused fewer problems than tobacco and alcohol.

People who occasionally used cannabis had few health problems. Long-term
and heavier users could suffer subtle cognitive impairment.

Research had not shown that cannabis use damaged the brain structure, he
said. But in high doses it could cause acute psychosis. Cannabis did not
cause schizophrenia, but it might trigger the illness in people at risk.

No more than 2 or 3 percent of the population was at serious risk, he said.

Dr Judson said research showed cannabis could have a useful therapeutic
effect, particularly for pain and stress relief.

The select committee will look at the effect of cannabis on people's
development, the role of cannabis as a trigger for mental illness, the
effects of cannabis on Maori mental health and the adequacy of services for
those with drug-related mental illnesses.

The committee was told that about 10 percent of cannabis users had a
dependency problem, which was a similar level to those on other drugs but
much less than tobacco users.

Dr Mark [sic] David Hadorn, who heads the Drug Policy forum Trust, said the
pharmacological effects of cannabis were relatively benign.

He said it was important to consider the research and not get distracted by
anecdotal evidence about the small number of people who had problems.

"The research evidence shows that cannabis is at most a small contributor
to the development and exacerbation of mental illness throughout the world."

Dr Hadorn said anti-drug campaigns aimed at children increased drug use
because they stimulated curiosity.

Trust member Dr Peter Crampton, from Wellington School of Medicine, said
the criminal status of cannabis made the mental health consequences worse.
Cannabis use had decreased or remained the same in countries or states
where its use had been decriminalised. - NZPA

Checked-by: Mike Gogulski