Early Pubertal Timing Predicts Suicidality and Self-Injurious Behaviors in Preadolescents: Evidence for Concurrent and New-Onset Risk

Importance: New predictors of self-injurious thoughts and behaviors (SITBs) in preadolescence are urgently needed to address this escalating public health crisis of youth self-harm and suicidality. Early pubertal development is easily assessed and theoretically justified, yet strikingly absent from current conversations of SITB risk. Objective: Determine whether advanced puberty at age 9/10, relative to same-aged peers, predicts current and/or new-onset SITBs. Design: This longitudinal study used data from the baseline, 1-year, and 2-year follow-up waves of the Adolescent Brain and Cognitive Development Study. Setting: Data were collected at 22 study sites in the US between 06/01/16 and 01/15/21.Participants: 11,878 preadolescents (baseline ages 9/10 years) and caregivers participated in the baseline wave.Exposure: Relatively advanced youth-reported pubertal development at 9/10 years.Main Measures: SITBs (suicidal ideation, suicide attempts, and non-suicidal self-injury) as reported by preadolescents (each wave) and their caregiver (baseline, 2-year follow-up) in a computerized version of the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS). Results: Preadolescents with baseline self-reported puberty, KSADS (N=8,708; 44.6% female; 60.8% white non-Hispanic), and demographic information were included. Bayesian mixed-effects models were estimated for test and replication split halves. Baseline preadolescent-reported puberty predicted the presence of any SITB before or at baseline (OR=1.50, 2.5% CI=1.23, 97.5% CI=1.85). Baseline puberty also predicted new-onset SITBs between baseline and 2-year follow-up in preadolescents SITB-naive at baseline (OR=2.26, 2.5% CI=1.66, 97.5% CI=3.21). Findings were similar for each SITB independently and when controlling for other known SITB risk-factors (familial depression, parental monitoring, family conflict, total symptoms) in follow-up and replication analyses. Associations between puberty and SITBs did not differ meaningfully by sex, race, or ethnicity.Conclusions and Relevance: Preadolescents reporting relatively advanced puberty at 9/10 years were more likely to have previously experienced SITBs and, if SITB naïve, were more likely to experience onset of SITBs across the following two years. Findings were not explained by child psychopathology or other familial and psychosocial factors known to predict SITBs. Screening preadolescents for advanced puberty at age 9/10 and applying targeted suicide-screening for those youth showing advanced puberty should be considered in primary care and mental health settings.