Outcome and cost-effectiveness of transdiagnostic cognitive behavioral therapy compared with management as usual for youth with common mental health problems: Long-term results from the Mind-My-Mind randomized trial

Background: Credible long-term outcomes from randomized trials evaluating the effectiveness and cost-effectiveness of preventive programs for mental health problems are needed. We compared long-term effects of the Mind My Mind (MMM) transdiagnostic cognitive behavioral therapy (CBT) program to management as usual (MAU). Methods: The study was a pragmatic, multisite, randomized superiority trial (2017–2019) involving youths aged 6–16 years with anxiety, depressive symptoms, and/or behavioral disturbances, recruited through family self-referral. The MMM intervention included 9–13 weekly CBT sessions. The primary outcome was change from baseline in parent-reported impact of mental health problems at 3-year follow-up post-randomization using the Strengths and Difficulties Questionnaire (SDQ) impact scale. Register-based outcomes tracked youths' psychiatric diagnoses in mental health services. To assess cost-effectiveness, we calculated the incremental costs and incremental quality-adjusted life years (QALYs). All primary analyses followed the intention-to-treat (ITT) approach. Clinical trials registration: ID NCT04804917. Results: Among 396 youths randomized (baseline mean [SD] age, 10.3 [2.4] years; 52.0% boys; MMM n = 197, MAU n = 199), the 3-year follow-up (median 167 weeks; range 124–203 weeks) primary outcome data were available in 69.0% and 59.3%, respectively. The decrease in SDQ-impact-score from baseline to 3-year follow-up (4.12→1.79 points [MMM] and 4.21→1.85 [MAU]) was similar (between-group difference, 0.06 [95% CI −0.41 to 0.52]; p =.81). An equal proportion (25%) of youths in MMM and MAU were diagnosed with any mental disorder during follow-up (HR 1.01, 95% CI 0.68–1.50). Total costs over the intervention period were higher in the MMM group (incremental costs 3,014 Euros [95% CI: 2.174–3.855]). Cost-effectiveness analyses favored MMM: QALY net gain 0.121 (95% CI 0.045–0.196); the cost-effectiveness ratio was 24,789 Euro/QALY. Conclusions: Although MMM was potentially cost-effective, the beneficial effects diminished over 3 years post-treatment. The findings highlight the need for strategies to sustain long-term effects.