Tell Rufus May that "doctor knows best" and he would have a few words to say about it. When he was just 18, a psychiatrist diagnosed him with paranoid schizophrenia and told him he would have to take medication for the rest of his life.

May, who was suffering from delusions, was admitted to psychiatric hospital. He did take his medication for a while, but became so upset by its disabling sedative effects that he started to refuse. It was then that he experienced psychiatry's powers of compulsory treatment, when six nurses pulled his trousers down to his ankles, pinned him to the ground and injected tranquillisers into one of his buttocks.

May was left traumatised and unable to trust his doctors. So after his discharge, and against all advice, he never returned to hospital. Instead, he went to live in a squat and, despite his confused state of mind, came off all medication. He eventually got a job as a night security guard at Highgate cemetery in north London.

Thirteen years on and May has not taken anti-psychotic medication since. His recovery is one that few patients - let alone mental health professionals - would go through. Yet May is now a clinical psychologist and is using his experience of being a psychiatric patient to challenge the traditional medical model for treating those who, like him, are diagnosed with severe mental illness.

"When I was a patient I felt misunderstood and written off," he says. "I thought I was treated cruelly. When I was forcibly treated and injected, it felt like rape."

May, who still suffers nightmares of being readmitted to hospital and being compulsorily medicated, channels his anger productively, arguing that as long as psychiatry's medical model continues to understand severe distress as rooted in biology, rather than experience, thousands of patients will be denied a fair chance of recovery.

With psychiatry's compulsory treatment powers, and a tendency to confuse the withdrawal effects of medication with symptoms, May fears vulnerable patients quickly become dependents. And, as it was for him, May believes that too often the mental health service handles patients inappropriately right from the beginning.

Before his admittance to hospital, May had been living in a "day- dream fantasy world" to escape a dull job as a draughtsman. He entertained theories that he was a spy and the television was broadcasting messages to him. When he was referred to two psychiatrists, they both listened as he told them his perception of the world. They scribbled notes. But not once did they question him about his views.

May was in and out of hospital for the next seven months - long enough to feel treated like a "social, moral and genetic outsider". But it was different when he joined the squatters, with whom he could share his bizarre thoughts without being seen as relapsing.

He came off his medication without professional help and managed to see through the surges of mania and restlessness which accompany withdrawal. But he was still too afraid to return to his psychiatrist. So he used his friends, and those he met at community centres and churches, slowly to rediscover his social skills and confidence.

After a number of casual jobs, May embarked on a psychology degree and, in what became a remarkable recovery, finally trained as a clinical psychologist at the University of East London. Yet throughout six years of study, he never revealed his past diagnosis.

This secret led to some tense encounters, particularly when May went to do placements in hospitals close to where he had been treated. He would bump into nurses and other patients whom he knew from his own patient days. "I remember one meeting when I saw it dawn on a nurse's face that he recognised me," he recalls. "Afterwards, the nurse told me not to worry and said my diagnosis was confidential and he would not tell anyone. I felt like an undercover agent spying on psychiatry. I had become the spy that I was in my delusions."

It was only after May had qualified that he "came out" to his colleagues about his schizophrenia diagnosis. May is now into his second year working as a clinical psychologist in Tower Hamlets, east London. He prefers to use a more "collaborative" approach when treating those diagnosed with psychotic illnesses. The first thing he will do is, quite simply, talk openly with patients.

"When I was a patient it was believed that talking about psychosis made it worse," he says. "But I prefer making sense with a person about their experience."

May has spent much time reflecting on what happened to him and believes his problem could have been more accurately defined as a severe identity crisis triggered by the breakdown of a relationship. "I believe that time, rest, low levels of short-term medication and discussing my experiences would have been the quickest route to a restoration of good mental health," he says.

Above all, May, who has built alliances with the mental health user movement, believes professionals should start redefining their relationships towards patients. "It is not right to say 'doctor knows best'. Psychiatrists and other professionals do have an expertise. But treatment will fail if they do not engage with clients who have an expertise about their own life. We should be coming to an agreement with clients about their treatment, rather than trying to impose it. Often, compulsory treatment is not necessary - it just drives people away from asking for help. And that can be dangerous."

The Guardian; Manchester (UK); Oct 4, 2000; Peter Kinderman;

It is sometimes said that "dog bites man" is not news, whereas "man bites dog" will guarantee coverage. In that light, can I congratulate you for your thought-provoking and sensitive account of Rufus May's experiences in and around the mental health services (Spying on the psychiatrists, September 20).

The world seems obsessed with headlines such as "Free to kill - lunatics left to roam streets butcher 90 people a year" (News of the World). It is therefore life-affirming to read a story that essentially boils down to "man has psychotic experiences, yet survives the mental health services and goes on to contribute positively to the world".

Thank you for reaffirming at least a minimal faith in the power of journalism.

Peter Kinderman, reader in clinical psychology, University of Liverpool