Association between nonsuicidal self-injury and borderline personality features in early-adolescent students: a cross-sectional study.

Background: Borderline personality disorder (BPD) is a disabling mental health condition marked by affective, cognitive, behavioral, and interpersonal instability. Borderline personality features (BPF) often emerge during adolescence and can predict later BPD. Nonsuicidal self-injury (NSSI) - the deliberate, direct infliction of tissue damage without suicidal intent - has shown a strong association with BPF. This study examined the relationship between NSSI and BPF in early-adolescent students. Methods: In this cross-sectional survey, 244 first-cycle high-school students in Urmia, Iran, were recruited; 228 provided complete data. After obtaining informed consent, participants completed the BPF Scale for Children (BPFS-C) and the Inventory of Statements About Self-Injury (ISAS). Data were analyzed using SPSS 24 with correlation and logistic regression models. Results: The mean BPFS-C score was 51.82 (boys = 51.41, girls = 54.56). Overall, 31.1% of participants reported at least one lifetime episode of NSSI. Cutting/scratching (26.7%), hair-pulling (14.0%), and hitting oneself (11.2%) were the most common methods. Emotion regulation was the most frequently endorsed function of NSSI (52.1%). Total BPF scores correlated positively with NSSI severity (r = 0.36, P < 0.05) and explained roughly 48% of its variance, with the self-destructive subscale contributing the greatest unique variance (sr2 = 0.31). Logistic regression indicated that a one-standard-deviation increase in self-destructiveness, affective instability, identity disturbance, and negative relationships increased the odds of NSSI by approximately six-fold, 59, 31, and 18%, respectively. Burning and carving were the strongest behavioral predictors of higher BPFS-C scores, while sensation seeking, antidissociation, expression of distress, interpersonal influence, and emotion regulation functions were linked to more frequent NSSI. Conclusions: Moderate levels of BPF were observed in this early-adolescent sample, with higher mean scores among girls. The high prevalence of NSSI is alarming and may foreshadow later impulsive or suicidal behaviors. Parental divorce was also associated with elevated BPF. These findings highlight the need for early screening and targeted interventions to mitigate the progression of borderline traits and self-injury risk in adolescents.