Joint Developmental Pathways of NSSI and Depressive Symptoms in Emerging Adults (Three-Wave Panel, 2021–2022)

This dataset derives from a three-wave longitudinal study designed to map the joint developmental trajectories of non-suicidal self-injury (NSSI) and depressive symptoms in emerging adults, and to examine interpersonal predictors of trajectory membership. Data were collected from university students at three six-month intervals (T1 = 1 October 2021; T2 = 1 April 2022; T3 = 1 October 2022). The original sample comprised 520 respondents; after data-quality screening (including validity items) the analytic sample includes 512 complete cases. Key variables include: self-reported NSSI behaviors (frequency/severity), depressive symptom scores (10-item CES-D), measures of four interpersonal domains (parent-child, peer, teacher-student, and dormitory relationships), and standard demographics.