Trajectory classes of suicidal ideation and anhedonia among Chinese vocational school students: Links with childhood trauma, school bullying victimization, and emotion regulation

Chinese vocational school students exhibit a higher prevalence of suicidal ideation (SI) than the general adolescent population. Given anhedonia's transdiagnostic nature, its predictive value for SI, influence on recovery, and shared neurobiological basis, integrating it into SI research provides a theoretically robust direction. Guided by the interpersonal theory of suicide, this longitudinal study investigated joint trajectories of suicidal ideation (SI) and anhedonia and examined differences between these trajectory classes regarding childhood trauma (CT), school bullying victimization (SBV), and emotion regulation strategies. A three-wave longitudinal survey (N = 1892, mean age 15.23 ± 0.80 years, 72.6 % female) with bivariate growth mixture modeling (GMM) was conducted. Longitudinal GMM identified Low and Decreasing (36 %), Moderate SI-High Anhedonia and Increasing (39 %), High SI-Moderate Anhedonia and Decreasing (9 %), and High and Increasing (16 %) trajectories. It found that emotional neglect and expressive suppression (ES) predicted high risk and symptom escalation; sexual abuse predicted high anhedonia; cognitive reappraisal (CR) deficits were associated with worsening anhedonia; ES predicted increased SI and anhedonia. The current study showed that SI and anhedonia heterogeneity reflected developmental pathways shaped by trauma exposure and emotion regulation capacities. Emotional neglect and ES were transdiagnostic risk markers, highlighting the importance of personalized early interventions.