Predicting suicide attempts by time-varying frequency of nonsuicidal self-injury among Chinese community adolescents

Objective: This study predicted suicide attempts (SA) by time-varying frequency of nonsuicidal self-injury (NSSI) beyond the contributions of their shared risk factors and examined gender differences in this association. This study also tested for a moderating effect of NSSI in the relationship between suicide ideation (SI) and SA. Method: A large number of Chinese adolescents participated in this study (the exact number of participants varied from 3,623 to 6,911 in different analyses). They completed questionnaires assessing NSSI, SA, SI, borderline personality disorder features, depressive symptoms, and self-criticism 3 times at 6-month intervals. Generalized estimating equations were used to test the hypotheses. Results: In females, but not in males, NSSI was significantly associated with future SA after controlling for the effects of shared risk factors. With the same frequency of SI, the frequency of NSSI also enhanced the risk for future SA. Conclusions: This study established a longitudinal association between NSSI and SA, which could not be fully accounted for by their shared risk factors, in Chinese female community adolescents. Moreover, female adolescents who frequently engage in NSSI may gain the capability for attempting suicide.