The associations between non-suicidal self-injury and borderline personality disorder features among Chinese adolescents.

This study examined the relative importance of four major BPD features, that is, affective instability, disturbed interpersonal relationship, unstable sense of self, and behavioral impulsivity, in explaining the presence, initiation, repetition, and discontinuation of non-suicidal self-injury (NSSI) among a 2-year follow-up sample of 4,782 (68.5% girls) Hong Kong Chinese secondary school students. Affective instability, disturbed interpersonal relationship and behavioral impulsivity were significantly associated with the presence of NSSI both concurrently and longitudinally. These three BPD features were also related to the future initiation of NSSI. On the other hand, only behavioral impulsivity made a significant contribution to the repetition of NSSI. Additionally, a lower level of affective instability was also associated with quitting NSSI. We discussed some possible mechanisms underlying the effects of different BPD features on different developmental stages of NSSI.