Meta-analysis and systematic review of teacher-delivered mental health interventions for internalizing disorders in adolescents

A large proportion of emotional problems begin in adolescence and negatively impact quality of life into adulthood. There have been multiple teacher-delivered, classroom-based programs created to reduce internalizing problems amongst young people. This meta-analysis and systematic review aims to examine the effectiveness of teacher-delivered interventions for depression, anxiety, post-traumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD) symptoms in adolescents, and a range of factors that may impact outcomes. Database searches were conducted from PsycInfo, Medline (PubMed), Scopus, Cochrane Library and the British Educational Index (database inception to January 2020). Quality assessment of studies used the EPHPP Quality Assessment Tool. Fifty-two studies were identified that quantitatively assessed, via controlled design, intervention effects on internalizing disorder symptoms. Three meta-analyses found teacher-delivered interventions were significantly better than control conditions at improving depression (g = -0.12), anxiety (g = -0.13) and PTSD symptoms (g = -0.66) in students. Improvements were only maintained at follow-up for anxiety symptoms and no effect sizes reached a ‘small’ threshold. However, the effect sizes were ‘moderate’ within the context of universal prevention programs for young people. No interventions measured OCD outcomes. Improved outcomes were associated with interventions that lasted up to 16 weeks, had 45-90 minute long sessions and included two or more days of teacher training. Future studies should report number of sessions taught, quality of teacher training and fidelity of intervention. Analysis of outcomes for participants with high versus low baseline mental health scores would enable a better understanding of for whom interventions are most effective.