[Non-suicidal self-injury and exposure to suicidal behaviors among Chinese adolescents: a longitudinal study].

Objective: Non-suicidal self-injury (NSSI) in adolescents appeared prevalent and multifactorial. This study was to examine the associations between exposure to suicidal behaviors and NSSI in the Chinese adolescents. Methods: Participants included for analyses were 5 154 adolescent students who participated in the baseline survey in 2015 and the first follow-up survey in 2016 of the Shandong Adolescent Behavior and Health Cohort, but with no history of NSSI at the baseline survey. A self-administered structured questionnaire was used to collect data on demographics, behavioral and emotional problems, lifetime and last-year NSSI. Data on the history of exposure to suicide attempt or death of a family member, friend, or close acquaintance were also collected. Multivariate logistic regression methods were used to examine the associations between exposure to suicidal behaviors and NSSI. Results: In the baseline survey, mean age of the 5 154 participants was (14.49±1.48) years, with 48.5% of the participants as girls. Of the participants, 9.0% reported having been exposed to suicidal behaviors, including 6.0% reported to suicide attempt, 4.9% to suicide death, 7.3% to suicidal behaviors of friends/close acquaintances, and 3.1% to suicidal behaviors of relatives. The prevalence rates of NSSI in the last year were significantly higher in adolescents who had been exposed to suicidal behaviors than those who had not (P<0.05). Results from the multivariate logistic regressions showed that exposure to suicide death (OR=1.91, 95%CI: 1.22-3.01) or to suicidal behaviors of relatives (OR=1.79, 95%CI: 1.02-3.12) were both significantly associated with the increased risk of NSSI. Conclusions: Experiences related to exposure to suicide-death or suicidal behaviors of relatives were associated with increased risk of NSSI in adolescents. After the suicide events, psychological counseling and health education programs set for high-risk groups were helpful in promoting physical and mental health and preventing the attempt of self-injury in teenagers.