Source: Evening Post (New Zealand) Contact: http://www.evpost.co.nz/ Pubdate: July 30, 1998 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