Heterogeneous trajectories of suicidal ideation and depressive symptoms during an indicated school-based CBT intervention: a group-based trajectory modeling study

Background: Understanding how suicidal ideation (SI) and internalizing symptoms, including depressive (DS) and anxiety symptoms (AS) evolve during preventive interventions may help personalize care for adolescents at risk of suicide. Few studies have examined joint trajectories of SI and internalizing symptoms within indicated school-based cognitive behavioral therapy (CBT) programs to reduce SI. Methods: This secondary analysis used data from the intervention arm of a cluster randomized controlled trial evaluating Reframe-IT+, a blended CBT-based school intervention delivered in Chile to 51 adolescents aged 13–18 years at risk of SI. SI and internalizing symptoms were assessed at baseline, post-intervention, and at 14-, 24-, and 36-week follow-up. Group-based trajectory modeling identified SI and internalizing symptoms patterns, and dual-trajectory modeling examined their interrelation. Baseline clinical and demographic associations were tested non-parametrically. Results: Two SI trajectories emerged: “decreasing & low” (90.0%), ending below the clinical cutoff, and “stable & high” (10.0%), remaining well above it. Two trajectories of internalizing symptoms were identified: “decreasing & normal” (46.6%) and “decreasing & mild” (53.4%). SI and internalizing symptoms trajectories only partially overlapped: adolescents with “decreasing & normal” internalizing symptoms were more likely to show favorable SI outcomes, whereas all in the “stable & high” SI group belonged to the “decreasing & mild” symptom group. Higher baseline depression, anxiety, and SI were associated with less favorable trajectories. Psychotic experiences levels were higher in less favourable trajectory group at follow-up. Males were more likely to follow the “decreasing & normal” trajectory of internalizing symptoms. Conclusions: Adolescents receiving indicated school-based CBT followed heterogeneous and partially independent SI and internalizing symptoms trajectories. Monitoring these patterns and suicide-related correlates, such as psychotic experiences, may inform stratified or stepped-care strategies to improve prevention effectiveness. Trial registration: NCT05229302. Registered on January 27th, 2022.