Impulsivity as a predictor of self-harm onset and maintenance in young adolescents: a longitudinal prospective study

Background: Rates of self-harm in young adolescents are increasing and self-harm typically emerges at this developmental stage. Greater specificity of impulsivity as a multifaceted construct is enabling investigation of links between individual impulsivity facets and self-harm outcomes. However, studies have yet to adequately explore these associations in young adolescents, and prospective relationships between multidimensional impulsivity and self-harm in younger adolescents remain untested. This study investigates unidimensional facets of impulsivity as risk-factors for the emergence and maintenance of self-harm, specifically within young community-based adolescents. Methods: A school-based sample of 594 adolescents (aged 13-15 years) provided data at two time points, 12 weeks apart. Logistic regression analyses determined associations between impulsivity-related facets (as delineated by the UPPS-P scale) and self-harm outcomes over time. Results: Overall, 23.6% of young people reported lifetime self-harm. A higher tendency towards Sensation Seeking was associated with self-harm onset over the study-period (OR 1.19, 95% CI 1.017-1.401). Deficits in Premeditation predicted maintained (versus remitted) self-harm behaviour during this time (OR 1.16, 95% CI 1.013-1.328). Negative Urgency was a significant cross-sectional correlate, but did not offer prospective predictive utility. Limitations: The study relied on self-report. Interpretations are cautious given low incidence of self-harm outcomes over the course of the study. Conclusions: Separate pathways to impulsive behaviour describe the psychological context in which self-harm starts and develops in young people. Findings support differential treatment targets and developmentally-focused early intervention. The predictive utility of impulsivity was inconsistent between cross-sectional and longitudinal analyses, underlining the role for temporality in the establishment of risk of self-harm.