Cumulative Interpersonal Risk, Non-Suicidal Self-Injury, and Suicide Attempts in Early Adolescence: Between-Person Differences and within-Person Effects.

Poor interpersonal relationships are one of the risk factors for non-suicidal self-injury (NSSI) and suicidal behaviors among adolescents. Previous studies have mostly focused on a single interpersonal perspective, and it remains uncertain how the cumulative interpersonal risk across time and domains interacts with NSSI and suicide. The current study employed cross-lagged panel models (CLPM) and random intercept cross-lagged panel models (RI-CLPM) to investigate the interaction among cumulative interpersonal risk, NSSI, and suicide attempts at both the between-person and within-person levels, while examining sex differences in these relationships. A total of 1038 Chinese adolescents (47.0% girls; baseline M_age = 12.35 years, SD = 0.52) participated in a four-wave longitudinal survey with 6-months intervals. The results showed that at the between-person level, there were reciprocal predictive relationships between cumulative interpersonal risk, NSSI and suicide attempts. At the within-person level, changes in NSSI affected changes in cumulative interpersonal risk, and suicide attempts exhibited a reciprocal relationship with cumulative interpersonal risk and NSSI, with significant sex differences observed. These findings underscore the stable and trait-like associations between cumulative interpersonal risk, NSSI and suicide attempts. Given these findings, to reduce the occurrence of suicide among adolescents, it is essential to target interventions aimed tat enhancing their interpersonal adaptability.