Death by unnatural causes during childhood and early adulthood in offspring of psychiatric inpatients

Context: Offspring of psychiatric inpatients are at higher risk of death from all causes, but their cause-specific risks have not been quantified. Objective: To investigate cause-specific deaths at 1 to 25 years in offspring of parents previously admitted as psychiatric inpatients. Design: Population-based cohort study. Setting: The entire Danish population. Participants: All singleton births (N=1.38 million) from January 1, 1973, to December 31, 1997, with follow-up to January 1, 1999. Linkage to the national psychiatric register identified all previous parental admissions. Main Outcome Measures: Deaths from all natural causes and all unnatural causes, specifically, accidents, homicides, suicides, and undetermined causes. Results: The highest observed relative risk (RR) was for homicide in young and older children with affected mothers or fathers. Homicides were between 5 and 10 times more likely to occur in this group, according to child's age and whether the mother or father had been admitted. There was previous parental admission in approximately one third of all child homicides. We found no evidence of increased risk of homicide in exposed young adults, but this group had a 2-fold to 3-fold higher risk of suicide. In almost one fourth of the suicides, there was a history of parental admission. Young adults with 2 previously admitted parents were 6 times more likely to kill themselves than were their peers in the general population. Relative risk of suicide or open-verdict deaths by poisoning were higher than for such deaths occurring by other means. Conclusions: Almost 99% of children studied survived to their mid-20s. However, they were more vulnerable to death from unnatural causes, notably, homicide during childhood and suicide in early adulthood. Further research is needed to establish how parental psychopathology contributes to increased risk of premature death in these offspring.