The following is a short excerpt from a very long story in the January, 04 article in "The Times of London "

THERE WAS SOMETHING horribly fast and terribly chilling about the onset of Steve Hammond's psychosis. His father Terry remembers feeling a shiver down his spine when, sitting in front of the television, Steve turned to him with a strange look in his eyes and said: "Why did you ring up the BBC?"

"Of course, I told him I hadn't," Terry recalls. "But then Steve said: 'Yes you did. You rang them up and told them I'm a lazy, useless bastard. And they've been broadcasting it all day.'"

This was the start of three years of hell for the Hammond family; three years during which Steve, a bright, handsome and popular 22-year-old, descended into madness and despair. For Terry it was the moment when he first saw the illness for himself. For Steve it was a frightening repeat of an episode a few days earlier when, with no papers to roll a joint, he ate a chunk of cannabis resin and collapsed in a nightclub toilet. "When I woke up I heard someone saying: 'It's OK Steve, you can get up now, you're all right'," he recalls. "When I looked around, there was no one there.

"That's when my voices started and I've had them ever since. I was so scared you can't imagine. I had voices coming from everywhere - the ceiling, the floor, in my head. It was the most frightening nightmare you could imagine, except I was awake."

Steve is one of 210,000 people in the UK who suffer from schizophrenia, and one of a growing number who believe cannabis caused their condition. Ten years ago psychiatrists would have disagreed with him. But three weeks before the Government is due to reclassify cannabis from a Class B to a Class C drug, that view has changed dramatically. Some of Britain's most senior psychiatrists say the drug is now the "No 1 problem" facing mental health services. Psychiatrists in inner-city areas speak of cannabis being a factor in up to 80 per cent of schizophrenia cases, and mental health specialists are bracing themselves for an increase in the problem as reclassification is misinterpreted as an assurance that the drug is safe.

For years psychiatrists have noticed a high level of cannabis use among people with psychosis, a generic term for schizophrenia, delusional episodes, manic depression and so on. But it had always been regarded as a chicken and egg problem; sufferers tended to have behavioural problems as adolescents and were more likely to use drugs to counter their often miserable lives. But all that changed two years ago when a group of researchers had the idea of relating cannabis and psychosis to the Dunedin group, a continuing long-term study of 1,000 children - now adults - in New Zealand. They found that those who used cannabis by the age of 15 were more than three times (i.e. 300% higher) as likely to develop illnesses such as schizophrenia.

Robin Murray, a professor at the Institute of Psychiatry and a consultant psychiatrist at the Maudsley Hospital in South London, took part in the groundbreaking research that first solved the chicken-and-egg problem. His co-authored report, published a year ago, concluded: "Although most young people use cannabis without harm, a vulnerable minority experience harmful outcomes. A tenth of the cannabis users by age 15 in our sample developed schizophreniform disorder by age 26 compared with 3 per cent of the remaining cohort. Our findings suggest that cannabis use among psychologically vulnerable adolescents should be strongly discouraged by parents, teachers, and health practitioners. Policy makers and lawmakers should concentrate on delaying onset of cannabis use."

In an interview with The Times, Professor Murray adds: "Unfortunately there were no experts in psychosis on the committees (the Home Affairs select committee and the Advisory Council on the Misuse of Drugs) that advised the Government on re-classifying cannabis. That's not a criticism - at the time, no one thought there should have been. Since then there have been at least four studies that show the use of cannabis can significantly increase the likelihood of the onset of psychosis.

"I would say this is now the No 1 problem facing the mental health services in inner cities. In south London the incidence of psychosis has doubled since 1964. There is a terrible drain on resources. Not only are there people suffering from psychosis who would not be in in-patient beds if they were not using cannabis, but use of the drug also drastically reduces the chances of recovery. People who do improve go out on the streets, meet their old dealer, begin using the drug again and relapse. We're not saying that the Government shouldn't reclassify cannabis - for most people it causes no problems - but I am saying that if they're going to do it they should warn people of the possible downside."

More information: See our section on Schizophrenia and Marijuana / Cannabis