Suicide and mental illness in parents and risk of suicide in offspring

Background A family history of completed suicide and psychiatric illness has been identified as risk factors for suicide. Aims To examine the risk of offspring suicide in relation to parental history of suicide and other parental risk factors. Method The study population consisted of 7,177 adult offspring born 1959–1961 and their parents from the Copenhagen Perinatal Cohort. Cohort members and their parents who had committed suicide were identified in the Danish Causes of Death Registry (follow-up until December 31, 2005), while information on psychiatric hospitalisation history was obtained from the Danish Psychiatric Central Research Register. Results Forty-eight cohort members, 77 mothers and 133 fathers had committed suicide during the follow-up. Independent of parental psychiatric illness and social status, parental suicide significantly increased suicide risk in offspring (hazard ratio 4.40 with 95% CI 1.81–10.69). A stronger effect of parental suicide was observed in offspring without a history of psychiatric hospitalisation. Conclusion Parental history of suicide is a risk factor for suicide in offspring, but primarily in offspring without psychiatric hospitalisation.