Suicide after release from prison: a population-based cohort study from Sweden.

OBJECTIVE Released prisoners have high suicide rates compared with the general population, but little is known about risk factors and possible causal pathways. We conducted a population-based cohort study to investigate rates and risk factors for suicide in people previously imprisoned. METHOD We identified individuals released from prison in Sweden between January 1, 2005, and December 31, 2009, through linkage of national population-based registers. Released prisoners were followed from the day of release until death, emigration, new incarceration, or December 31, 2009. Survival analyses were conducted to compare incidence rates and psychiatric morbidity with nonconvicted population controls matched on gender and year of birth. RESULTS We identified 38,995 releases among 26,985 prisoners (7.6% female) during 2005-2009. Overall, 127 suicides occurred, accounting for 14% of all deaths after release (n = 920). The mean suicide rate was 204 per 100,000 person-years, yielding an incidence rate ratio of 18.2 (95% CI, 13.9-23.8) compared with general population controls. Previous substance use disorder (hazard ratio [HR] = 2.1; 95% CI, 1.4-3.2), suicide attempt (HR = 2.5; 95% CI, 1.7-3.7), and being born in Sweden versus abroad (HR = 2.1; 95% CI, 1.2-3.6) were independent risk factors for suicide after release. CONCLUSIONS Released prisoners are at high suicide risk and have a slightly different pattern of psychiatric risk factors for suicide compared with the general population. Results suggest appropriate allocation of resources to facilitate transition to life outside prison and increased attention to prisoners with both a previous suicide attempt and substance use disorder.