Early parental death and risk of hospitalization for affective disorder in adulthood.

Background: Early parental death is one of the most stressful childhood life events and may influence subsequent psychological health. We investigated the association between early parental loss and risk of hospitalization for an affective disorder in adulthood. Methods: Our nationwide register-based cohort study comprises 1,225,660 people born in Denmark in 1970-1990, of whom 138,893 experienced the death of a parent before the age of 30 years. Follow-up for hospitalization for an affective disorder in the period 1990-2009 yielded 15,261,058 person-years and 19,867 hospitalizations for affective disorder (bereaved n = 2,644; nonbereaved n = 17,223). A Cox proportional hazards model was used to assess hazard ratios (HRs) for hospitalization with an affective disorder according to early parental death. Results: People who experienced early parental death had an increased risk of hospitalization for a unipolar disorder (men: HR= 1.33; 95% confidence interval [CI] = 1.23-1.44; women: 1.23; 1.17-1.30). Stronger associations were observed for parental death caused by suicide than for other causes. For bipolar affective disorder, an increased risk of hospitalization was observed only after suicide. Conclusions: People who had lost a parent had an increased risk of hospitalization for unipolar affective disorder. Although this was particularly true for bereavement due to parental suicide, it was also found for parental death from other causes. In contrast, an increased risk of hospitalization for bipolar affective disorder was observed only after parental suicide.