Childhood temperament as a predictor of adolescent nonsuicidal self-injury.

Previous cross-sectional work has consistently found associations between neuroticism and impulsivity and nonsuicidal self-injury (NSSI). However, there are few longitudinal studies of personality risk factors for NSSI. In this study, we examined associations between individual differences in temperament at age 3 and NSSI from ages 9 to 15. At age 3, 559 preschool-aged children (54% male; Mage = 42.2 months [SD = 3.10]) completed laboratory assessments of temperament. Parents also completed questionnaires about their child's temperament. Children completed a diagnostic interview assessing NSSI engagement at ages 9, 12, and 15. By the age 15 assessment, 12.4% of adolescents reported engaging in NSSI. In univariate models, we found that higher levels of observed sadness and maternal-reported sadness and anger were associated with increased risk for NSSI. In multivariate models, female sex and maternal-reported anger were significantly associated with greater likelihood of NSSI. Laboratory observed sadness and impulsivity were associated with a higher likelihood of NSSI. This work extends the literature on personality risk factors associated with NSSI by finding longitudinal associations between early childhood negative affect and later NSSI engagement during adolescence.