Effectiveness and cost-effectiveness of universal school-based mindfulness training compared with normal school provision in reducing risk of mental health problems and promoting well-being in adolescence: the MYRIAD cluster randomised controlled trial

Abstract

Background Systematic reviews suggest school-based mindfulness training (SBMT) shows promise in promoting student mental health. Objective The MYRIAD trial evaluated the effectiveness and cost-effectiveness of SBMT compared with teaching-as-usual (TAU). Methods MYRIAD was a parallel group, cluster-randomised controlled trial. Eighty-five eligible schools consented and were randomised 1:1 to TAU (43 schools, 4232 students) or SBMT (42 schools, 4144 students), stratified by school size, quality, type, deprivation, and region. Schools and students (mean (SD); range age=12.2, (0.6); 11-14) were broadly UK population-representative. Forty-three schools (n=3678 pupils; 86.9%) delivering SBMT, and 41 schools (n=3572; 86.2%) delivering TAU, provided primary end-point data. SBMT comprised ten lessons of psycho-education and mindfulness practices. TAU comprised standard social-emotional teaching. Participant-level risk-for-depression, social-emotionalbehavioural functioning, and well-being at one-year follow-up were the co-primary outcomes. Secondary and economic outcomes were included. 3 Findings: Analysis of 84 schools (N=8,376 participants) found no evidence that SBMT was superior to TAU at one-year. Standardised mean differences (intervention minus control) were: 0.005 (95%CI: -0.05–0.06) for risk-for-depression; 0.02 (-0.02–0.07) for socialemotional-behavioural functioning; and 0.02 (-0.03–0.07) for well-being. SBMT had a high probability of cost-effectiveness (83%) at a willingness-to-pay threshold of £20,000 per QALY. No intervention-related adverse events were observed. Conclusions: Findings do not support the superiority of SBMT over TAU in promoting mental health in adolescence. Clinical implications: There is need to ask what works, for whom and how, as well as considering key contextual and implementation factors. Trial registration: Current Controlled Trials ISRCTN86619085.