IS CANNABIS use relatively harmless, or can it cause symptoms such as hearing voices and paranoia? After studying more than 2000 users and non-users aged between 14 and 24, Jim van Los of the University of Maastricht in the Netherlands concludes that it can.
鈥淭here is considerable harm associated with cannabis,鈥� van Los claims. 鈥淚t is not safer than alcohol or other drugs.鈥� After four years, 21 per cent of cannabis users in his sample had psychotic symptoms, compared with 15 per cent of non-users. The more often people used cannabis, the stronger the effect.
鈥淎fter four years, 21 per cent of cannabis users had psychotic symptoms鈥�
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The risk appears greatest for those with a predisposition to psychosis. In people with mild signs of psychosis at the start of the study, 51 per cent of users developed symptoms compared with 26 per cent of non-users.
However, several other reviews have come to a different conclusion. In 1998, a French government study found that cannabis was the least dangerous of all potentially addictive drugs.
