Parental death by external causes and risk of hospital-treated deliberate self-harm in bereaved offspring

Previous studies have reported an increased risk of hospital-treated deliberate self-harm (DSH) in offspring who have lost a parent, but inconclusive findings regarding differences between loss from suicide and accidents. The present study aimed to investigate the association between parental death by external causes before age 18 and hospital-treated DSH, and potential differences between different accidents and suicide. This nested-case–control study was based on data from longitudinal Norwegian registers. Subjects comprised 12,526 people born between 1970 and 2003 who received acute somatic treatment because of DSH at hospitals and associated services between 2008 and 2013 (cases), and 222,362 controls matched for gender and date of birth with no recorded DSH treatment. Information concerning deceased parent’s death and offspring’s DSH treatment and socioeconomic data was merged. Data were analysed with conditional logistic regression. Results indicated that offspring who had lost a parent to suicide (OR 2.32, 95% CI 1.92–2.80) and death by accidents such as falls, poisoning, and drowning (OR 1.79, 95% CI 1.38–2.33) had a significantly increased risk of hospital-treated DSH compared to offspring who had not experienced such loss. Parental bereavement from transport accidents and other external causes were not associated with significantly increased risks. No differences were evident for different genders of deceased, ages at bereavement, or genders of bereaved. The improved identification of bereaved offspring at particular risk of hospital-treated DSH should be utilized to implement effective prevention and treatment programs in specialist healthcare aimed at the individuals at highest risk.