Experience of maternal and paternal adversities in childhood as determinants of self-harm in adolescence and young adulthood

Introduction Previous studies suggest that childhood experience of parental adversities increases the risk of subsequent offspring self-harm, but studies on distinct paternal and maternal characteristics are few and it remains unclear how these interact with childhood social position. The study aims to assess whether paternal and maternal adversities have different associations with offspring self-harm in adolescence and young adulthood. Interaction by offspring gender and childhood income are investigated, as well as cumulative effects of multiple adversities. Methods The study uses administrative register data on a 20% random sample of Finnish households with children aged 0–14 years in 2000. We follow children born in 1986–1998 (n=155 855) from their 13th birthday until 2011. Parental substance abuse, psychiatric disorders, criminality and hospitalisations due to interpersonal violence or self-harm are used to predict offspring self-harm with Cox proportional hazards models. Results The results show a clear increase in the risk of self-harm among those exposed to maternal or paternal adversities with HRs between 1.5 and 5.4 among boys and 1.7 and 3.9 among girls. The excess risks hold for every measure of maternal and paternal adversities after adjusting for childhood income and parental education. Evidence was found suggesting that low income, accumulation of adversity and female gender may exacerbate the consequences of adversities. Conclusions Our findings suggest that both parents’ adversities increase the risk of self-harm and that multiple experiences of parental adversities in childhood are especially harmful, regardless of parent gender. Higher levels of childhood income can protect from the negative consequences of adverse experiences.