Decision making under risk and under ambiguity in depressed suicide attempters, depressed non-attempters and healthy controls

Abstract

Background: A number of neuropsychological alterations have been found in patients who have attempted suicide. Most studies investigating decision making (DM) abilities in suicide attempters so far have used one single DM task and included patients with a lifetime history of suicide attempts. These studies have yielded conflicting results.

Method: In this study, currently depressed in-patients who had a recent suicide attempt (within the last six months) (n = 21), depressed in-patients without a lifetime history of suicide attempts (n = 31) and a healthy control group (n = 26) were assessed with two tasks for the assessment of DM. The Game of Dice Task (GDT) measures DM under risk and the Iowa Gambling Task (IGT) DM under ambiguity. Further, depression severity, impulsiveness and suicidal intent of the current suicide attempt were assessed.

Results: Both depressed groups differed from controls with respect to marital and partnership status, smoking, impulsiveness and psychiatric family history. In terms of DM, IGT scores did not differ significantly between groups. However, suicide attempters made significantly more risky decisions as assessed with the GDT than both control groups (p < 0.05 for pairwise comparisons, p = 0.065 for overall comparison of the 3 groups).

Limitations: The available tasks assess DM under laboratory conditions which may not reflect the emotional status of suicidal individuals. No general cognitive assessment was included.

Conclusions: Depressed suicide attempters differed with regard to DM under risk but not DM under ambiguity. When studying DM it appears crucial to take varying aspects of DM into account.

Keywords: Decision making; Depression; Game of Dice Task; Iowa Gambling Task; Suicide attempt.