The authors used the Iowa Gambling Task to assess decision making in suicide attempters by investigating patients with a history of violent or non-violent suicidal behaviour, patients suffering from affective disorders with no history of suicidal behaviour, & healthy comparison subjects. Both groups of suicide attempters scored significantly lower than healthy comparison subjects, & violent suicide attempters performed worse than affective comparison subjects. Impaired decision making, due to emotional dysfunction, may be a neuropsychological risk factor for suicidal behaviour. (46 refs)