It is well known that there is a 30-40 times increased risk of death from suicide in individuals who have previously attempted suicide compared with the general population.
But little is known about the impact of coexisting psychiatric disorders on the risk of suicide in this group.
The research team led by Dag Tidemalm from the Karolinska Institutet in Stockholm analysed 40 000 individuals with 53pct women, who were admitted to hospital in Sweden following a suicide attempt during 1973-82.
They analysed how many suicides were completed during the 30 year follow-up and if the risk varied with type of psychiatric disorder.
The authors found that schizophrenia and unipolar/bipolar disorder were the strongest predictors of completed suicide throughout the follow-up period, reports the British Medical Journal.
Men with unipolar/bipolar disorder committed almost 64pct of the suicides, while 42 pct of suicides occurred in women, within the first year of the follow-up.
On the other hand 56 pct of the suicides occurred in men suffering from schizophrenia, while 54 pct occurred in women.
Death from suicide occurred mostly within the five years after the initial suicide attempt.
The authors suggest that patients who have unipolar/bipolar disorder or schizophrenia and previous suicidal behaviour are to be given more intensive after-care, especially in the first few years after trying to kill themselves.