A systematic review on the relationship between childhood exposure to external cause parental death, including suicide, on subsequent suicidal behaviour

Background: Exposure to parental death in childhood has been associated with offspring suicide risk, although the strength of this association is unclear. The primary aim of this systematic review was to synthesise primary studies on the relationship between childhood exposure to external cause parental death, including suicide, and subsequent suicidal behaviour in adulthood. The secondary objective was to compare suicide-related outcomes of exposure to parental suicide with the outcomes of exposure to other external cause parental deaths. Methods: A systematic review was conducted using guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Ovid MEDLINE, Cochrane Library, Ovid PsycINFO, Web of Science, CINAHL and EMBASE were searched from January 2008 until November 2018. Two researchers independently screened the articles, performed data extraction and assessed quality of evidence using the Newcastle-Ottawa Scale. Results: Of the 618 studies identified, 26 were included for review. Only one study found no significant association between childhood exposure to suicide and increased suicide risk in adulthood. Four studies suggested the risk of suicidality in adulthood was greater for those exposed to parental suicide compared to other external cause deaths. Limitations: The use of national registers in many studies did not allow for all variables of interest to be examined. Selective samples also limited the generalizability of findings. Conclusions: A strong association between parental suicide and suicidal behaviour in adult offspring exists. Interventions for bereaved youth should consider the long-term effects of parental suicide and target individual and environmental-level risk factors for subsequent suicidality.