Background: Adverse life events have been associated with increased risk of suicide. Mental disorders are also major risk factors for suicide. Matching cases and controls for mental disorder is thus appropriate in studies of suicide. This procedure was used to study the degree to which excess adversity was more common in cases who committed suicide as opposed to living controls matched for mental disorder.
Methods: The study formed part of a retrospective case-control comparison of cases of suicide/undetermined death with living controls using psychological autopsy in south-east Scotland. Cases and controls were matched for age, sex and mental disorder. Informants were those closest to cases and controls. Cases and controls were assessed for life events using the Interview for Life Events. The subjects were 45 cases of suicide/undetermined death and 40 living controls.
Results: Cases and controls did not differ significantly in severity of mental disorder. Adverse interpersonal events within the family (P = 0.01) with an odds ratio (OR) of 9.0 (95% CI, 1.3-399) and adverse physical health-related events (OR 5.0, 95% CI 1.1-47, P = 0.04) were significantly more common in cases than controls.
Conclusions: Cases had significantly more adverse life events than controls overall. The categories accounting for these differences were interpersonal family adversity and physical ill-health. There were no significant differences in either the number or severity of ongoing difficulties between cases and controls. Recent adverse life events contribute to the increased risk of suicide even when age, sex and mental disorder are controlled for. Future research should examine interactions between social support and acute and chronic adversity.