RESUMO
BACKGROUND: Little is known about trajectories of NSSI. We aimed to identify NSSI trajectories in adolescent psychiatric inpatients and emotional processes that differentiate between trajectories. METHODS: Participants were 180 adolescents (71.7 % female; mean age of 14.89 years, SD = 1.35) from a psychiatric inpatient facility. NSSI was assessed at their index hospitalization, as well as 6, and 12 months after discharge. Emotion recognition, emotion reactivity, and emotion dysregulation were assessed at baseline. Latent class mixture modeling was used to identify different NSSI trajectories and ANOVAs were used to evaluate predictors of the trajectories. RESULTS: Analyses yielded three NSSI trajectories. These included a stable low-frequency class (90.53 % of sample), a stable moderate-frequency class, and a class characterized by high-frequency NSSI at baseline but that largely resolves by 6-month follow-up. After adjustments for multiple comparisons were made, only emotion regulation at baseline differentiated between the trajectories, with greater overall emotion dysregulation and greater emotional non-acceptance (a facet of emotion dysregulation) characterizing the initially high-frequency class and the stable moderate-frequency class more than the stable low-frequency class (ps < .05). Difficulties engaging in goal-directed behavior when distressed characterized the stable moderate-frequency NSSI class more than the stable low-frequency class (p < .05). Limitations The study sample consists predominantly of female and White adolescents and thus may not generalize to other demographic groups. CONCLUSIONS: The current findings suggest that interventions involving emotion regulation with adolescents who engage in NSSI would particularly benefit from a focus on increasing acceptance of emotional experiences.