The half a million people with the condition have a 50 times higher risk of attempting suicide than the general population.

But experts say treating schizophrenia with the drug clozapine, an atypical antipsychotic, could reduce the number of suicide attempts, and therefore deaths.

Schizophrenia statistics

One suicide every 88 minutes (UK) Half a million people have schizophrenia Half of those will attempt suicide 5,000 commit suicide every year The government wants to cut suicides by 20% by 2010

The NHS drugs watchdog, the National Institute for Clinical Excellence (Nice), has said atypical anti-psychotic drugs should be more widely available, and that there should be a three-fold increase in the prescribing of clozapine.

They have fewer side-effects than older drugs, but are significantly more expensive.

The government is committed to reducing suicides by 20% by 2010.

'Use sooner'

The International Suicide Prevention Trial (Intersept) involved 1,000 people from 11 countries, most of whom had schizophrenia.

As many as 50 to 100 lives can be saved each year Professor Robert Kerwin, Institute of Psychiatry

The two-year study found using clozapine, (Clozaril) significantly reduced the risk of suicidal behaviour in people with schizophrenia.

The research compared users of clozapine with patients taking another drug thought to have some anti-suicidal benefits, olanzapine.

It was found those on clozapine were 25% less likely to attempt to take their own lives.

It suggested up to 1,000 people with schizophrenia could be saved over 10 years if they were given the right support and treatment.

Robert Kerwin, professor of neuropharmacology at the Institute of Psychiatry in London was one of the lead researchers in the Intersept study.

He told BBC News Online the aim of the study, which was funded by the makers of Clozaril, Novartis, had been to see if clinical observations that clozapine could reduce suicides was backed up by research.

He said: "As many as 50 to 100 lives can be saved each year by broader use of clozapine.

"Nice has said clozapine should be used sooner and more broadly in patients, so this study shows that it is highly life-saving.

"This study lends a lot of weight to the recommendations that Nice has made."

'Vulnerable people'

Campaigners welcomed the Intersept findings.

Paul Farmer of the charity Rethink (formerly the National Schizophrenia Fellowship) said: "This important research highlights the need to fully implement the NICE guidance on the use of the most modern medicines for schizophrenia, atypical antipsychotics, allied with social support.

"If the Nice recommendations are followed, many vulnerable people with schizophrenia will be helped and fewer may try to take their own lives."

But a survey by Rethink found it would be October 2005 before the Nice decision is fully implemented.

He added: "There is no 'magic medicine' solution for all. But with the right help at the right time, people can recover a full and meaningful quality of life."

The Intersept research was published in the Archives of General Psychiatry.