Pubdate: Thu, 30 Jul 1998 Source: NZ Herald (Auckland) Contact: CANNABIS A MINOR RISK TO MENTALLY UNSTABLE: DOCTOR WELLINGTON - Cannabis use has little effect on mental illness, apart from a small group of people suffering from schizophrenia or predisposed to the disease, MPs were told yesterday. Dr John Marks, who heads Capital Cost Health's drug and alcohol 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 and will report to Parliament and make recommendations to the Government. Dr Marks, a member of the Drug Policy Forum Trust, a doctors' group that supports decriminalising the drug, said cannabis use could worsen the condition of some schizophrenics - about one in 10,000 of the population. Dr Nick Judson, the Ministry of Health's deputy director of mental health, said cannabis caused fewer problems than tobacco and alcohol. People who used cannabis occasionally 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, said Dr Judson. No more than 3 per cent of the population was at serious risk. He said research showed cannabis could be therapeutic, particularly for pain and stress relief. The select committee announced its inquiry in April amid calls for the drug to be decriminalised. The inquiry will look at the effect of cannabis on people's development, the role of the drug 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. Ria Earp, the ministry's deputy director of Maori health, said more research was needed on the effects of cannabis on Maori mental health. More appropriate drug and alcohol services were needed for Maori. The committee was told that about 10 per cent of cannabis users had a dependency problem which was a similar level to other drugs but much less than tobacco. Dr Hadorn, who heads the doctors' trust, said the pharmacological effects of cannabis were relatively benign. It had been used for centuries and was well accepted for stress relief. He said it was important to consider the research, rather than be 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." People who dealt only with those who had problems with cannabis - such as police and health workers - had a very narrow view, he said. A trust member, Dr Peter Crampton, of the 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. Dr Hadorn said anti-drug campaigns aimed at children increased drug use because they stimulated curiosity. Children needed to be told at a young age they should not smoke cannabis. Dr Marks said studies of cannabis, dating back to last century, had all exonerated the drug. It was therapeutic for diseases such as glaucoma, multiple sclerosis, cancer and HIV. - NZPA - --- Checked-by: Melodi Cornett