The effect of social exclusion on intertemporal choice in suicide attempters: A preliminary experimental study

Suicide-related theories and a growing body of evidence suggest that suicidal patients may have a tendency toward "short-sightedness"-the preference for immediate gratification when making intertemporal choice-and that social exclusion may exacerbate this tendency in suicidal patients. The present study examined the intertemporal choice performance of suicide attempters under conditions of social exclusion in a sample of affective disorder patients.

A total of 64 affective disorder patients (22 non-suicidal patients, 24 single-suicide attempters and 18 multiple-suicide attempters) completed an intertemporal choice task in an exclusion or a non-exclusion condition. Social exclusion was manipulated using the Cyberball paradigm.

Non-suicidal patients and single-suicide attempters both exhibited an exaggerated preference for immediate rewards in the exclusion condition compared with the non-exclusion condition; in contrast, the multiple-suicide attempters appeared relatively indifferent to the social exclusion, exhibiting virtually identical preferences for immediate rewards in both the exclusion and non-exclusion conditions. In addition, the multiple-suicide attempters exhibited an exaggerated preference for immediate rewards compared with non-suicidal patients and single-suicide attempters in the non-exclusion condition, while the three groups did not differ in the exclusion condition.

Affective disorder patients with a single or no suicide attempts are more short-sighted after being excluded, while those with multiple suicide attempts appeared consistent short-sightedness in both exclusion and non-exclusion conditions. The study provides preliminary evidence of the role of disadvantageous intertemporal choice in the suicidal process. Future research replicate and extend these findings could have implications for suicide prevention and intervention.