Data on the incidence of deliberate self-harm (DSH) and suicide attempts (SAs) are lacking in non-Western adolescents, and no studies have investigated differences in incident DSH and SA worldwide. This study aimed to investigate the incidence rates and relationships between predictors in DSH and SA.
The Taiwanese Adolescent Self-Harm Project was a longitudinal study of DSH among adolescents. We recruited 5,879 students from 14 senior high schools in northern Taiwan. Online questionnaires on sociodemographic data, suicidality, depressive symptoms, self-esteem, social support, family discord, impulsivity, and alcohol and tobacco use were assessed at baseline (T1) and at 1 year of follow-up (T2). Logistic regression analyses were performed to evaluate the predictors of incident DSH and SA.
The mean age was 16.02 years, and 56.73% of the cohort was female. At T1, the lifetime prevalence rates of DSH and SA were 25.04% and 3.50%, respectively. At T2, 4,331 (73.67%) students had completed follow-up assessments. The 1-year incidence rates of DSH and SA were 4.04% and 1.53%, respectively. The predictors of incident DSH included perceived family discord and more depressive symptoms at T1. The predictors of incident SA were lifetime suicide ideation, more depressive symptoms, and tobacco use at T1.
The incidence rates of DSH and SA were similar to those reported in Western countries. The predictors of incident DSH and SA were similar but not identical. Our results highlight the risk factors which should be considered in terms of early identification and intervention among adolescents to prevent suicidality.