People who have already tried to kill themselves are 30-40 times more likely to commit suicide than other people. A Swedish study of 39,685 people who were admitted to hospital for attempted suicide between 1973 and 1982 looked at which mental-health problems increased the risk of these people going on to kill themselves. The study lasted until 2003 and the strongest predictor of completed suicide was schizophrenia, which increased the risk by a factor of 4.1 in men and 3.5 in women. Bipolar disorder and depression increased the risk by a factor of 3.5 in men and 2.5 in women. Increased risks were also found for anxiety disorders, alcohol misuse in women, drug misuse and personality disorders.
Tidemalm, Dag ... [et al] - Risk of suicide after suicide attempt according to co-existing psychiatric disorder: Swedish cohort study with long-term follow-up British Medical Journal December 6, 2008, 1328-1331