Longitudinal analysis of adolescent NSSI: The role of intrapersonal and interpersonal factors.

Non-suicidal self-injury (NSSI) occurs in approximately 10 % of adolescents. To establish effective prevention and intervention initiatives, it is important to understand onset, maintenance and cessation of NSSI. We explored whether the relationships between interpersonal factors (i.e. attachment, social support) and NSSI were mediated by intrapersonal factors (i.e. emotion regulation, self-esteem, self-efficacy). Participants were 1973 students (1414 female and 559 male) aged between 12 and 18 years (M = 13.89, SD = 0.97) recruited from 40 Australian high schools. Participants completed a questionnaire at two time-points with a 12-month interval. At baseline, 8.3 % of adolescents engaged in NSSI, increasing to 11.9 % at follow-up. Family support was most salient in onset, maintenance and cessation of NSSI. Attachment anxiety was related to NSSI onset. Of the intrapersonal variables, self-esteem and self-efficacy were significant in predicting onset of NSSI. Self-esteem, self-efficacy and cognitive reappraisal mediated the relationship between attachment anxiety and NSSI onset. A combination of interpersonal and intrapersonal variables contributes to the onset, maintenance and cessation of NSSI in adolescence. Perceived family support appears to be an important safeguard against NSSI. Strategies targeting family functioning and teaching cognitive reappraisal techniques to adolescents may reduce the number engaging in NSSI.