Schizophrenia and other psychotic disorder people are 12 times more likely to commit suicide. People with this disorder are left behind with disturbed thoughts.
The research found that the rate of suicide was highest in the first year following diagnosis (12 times national average) and that high risk persisted - remaining four times greater than the general population ten years after diagnosis, a time when there may be less intense clinical monitoring of risk.
A key aim of the study was to challenge the widely held view that "10-15 percent of people suffering psychotic disorders are likely to commit suicide".
This study shows that these figures, largely derived from research in the 1970s, are misleading as they use crude measurement techniques and do not accurately measure risk over a lifetime.
Today's findings indicate a lower overall risk, but more persistent danger of suicide among this patient group over a lifetime.
"It's well known that people who commit suicide often suffer serious mental health problems, but it's surprising that the risk they face remains so high ten years or more after first diagnosis," Rina Dutta, MRC Research Fellow and Honorary Consultant Psychiatrist, King's Health Partners, said.
"Putting a figure on it like this helps doctors to understand the extent of risk some of their patients face," she said.
The research studied a group of almost 3,000 patients in the UK who suffered their first psychotic illness between 1965 and 2004. The patients were traced after an average follow-up time of 11.5 years and their death certificates were analysed.
The study was released today by King's Health Partners.