Does higher-than-usual stress predict nonsuicidal self-injury?

Abstract

Background Nonsuicidal self-injury (NSSI) is highly prevalent among adolescent and emerging adult females. Most studies examining the relationship between stress and NSSI largely have relied on aggregate self-report measures of stress and between-person models. Using data from two prospective samples, this manuscript tests the hypothesis that within-person models of NSSI provide better clinical markers of risk for NSSI than between-person models of NSSI. Methods Two samples (Sample 1: 220 high-risk girls, M age = 14.68, SD = 1.36, baseline assessment and 3-month follow-ups for 18 months; Sample 2: 40 emerging adult females with a history of NSSI, M age = 21.55, SD = 2.14, 14 days with daily retrospective reports) were followed prospectively and completed validated measures of stress and NSSI. Models were adjusted for age and depression. Results In Sample 1, a within-person model demonstrated that higher-than-usual (but not average) stress levels predicted NSSI within the same 3-month wave. In Sample 2, results from a within-person model with daily diary assessment data showed that higher-than-usual stress (but not average daily stress) predicted same-day NSSI. Conclusions Together, our results suggest that higher-than-usual stress, relative to one's typical stress level, but not average stress levels, signals times of enhanced risk for NSSI. These results highlight the clinical utility of repeated assessments of stress.