Individual and parental psychiatric history and risk for suicide among adolescents and young adults in Denmark

Background Both individual and familial histories of mental illness are substantial risk factors for suicide in young people. Aim To explore suicide risk among adolescents and young adults according to detailed aspects of individual and parental psychiatric admission history. Methods A nested case–control study was undertaken using data from Danish population registers to include 4,142 suicide cases and 82,840 matched controls aged 9–35 years. Data were analyzed with conditional logistic regression. Results A history of hospitalized psychiatric illness was a strong risk factor for suicide in adolescents and young adults, and the effect of such a history was greater in females than males. The elevated risk peaked in the two periods immediately after admission and discharge for both sexes, and exceeded in females who had multiple admissions and in males who were diagnosed with schizophrenia, affective disorders or substance abuse disorders. At the same time, a parental psychiatric history constituted a substantial risk factor for suicide in young people, in particular, if having a mother admitted for psychiatric illness. The elevated risk associated with parental psychiatric history was greater in females than in males, and tended to be more prominent during the first few years after admission of a parent. Conclusion Prevention strategies should aim at improving treatment and care to young people with psychiatric problems and at providing social support and psychological consultation to children with parental psychiatric illness.