The effectiveness of an online interdisciplinary intervention for mental health promotion: a randomized controlled trial

BACKGROUND: There is an urgent need for efficacious interventions to combat the global mental health crisis, and mental health promotion and primary prevention approaches are paramount. The aim of this study is to examine whether an online interdisciplinary intervention that incorporates evidence-based strategies from the disciplines of Lifestyle Medicine and Positive Psychology improves measures of mental health and emotional wellness. METHODS: A randomized controlled trial with a wait-list control (N = 425, aged 46.97 ± 14.5, 69.9% females) was conducted in Australia and New Zealand. The intervention group participated in a 10-week online interdisciplinary intervention. Primary outcome measures of mental health and emotional wellness were taken at baseline (Week 1), post-intervention (Week 12), and 12 weeks post-intervention (Week 24). The wait-list control completed the same assessments. RESULTS: General Linear Modelling analyses indicated that the intervention group experienced significantly greater improvements than the wait-list control group over time in all outcome measures: mental health (F(319) = 7.326, p = 0.007) and vitality (F(319) = 9.445, p = 0.002) subscales of the Short Form Survey (SF-36); depression (F(319) = 7.841, p = 0.005), anxiety (F(319) = 4.440, p = 0.36) and stress (F(319) = 12.494, p < 0.001) scales of the Depression, Anxiety and Stress Scale (DASS-21); and life satisfaction (F(319) = 8.731, p = 0.003) as measured by the Satisfaction With Life Scale. Within the intervention group, significant improvements were observed from Week 1 to 12 in all outcome measures: mental health (10%, t(167) = − 6.423), p < 0.001, dz = 0.50), vitality (22%, t(167) = − 7.043, p < 0.001, dz = 0.54), depression (− 41%, t(167) = 6.189, p < 0.001, dz = 0.48), anxiety (− 38%, t(167) = 5.030, p < 0.001, dz = 0.39), stress (− 31%, t(167) = 6.702, p < 0.001, dz = 0.52) and life satisfaction (8%, t(167) = − 6.199, p < 0.001, dz = 0.48). Improvements in the outcome measures remained significant in the intervention group at 12 weeks post-intervention. CONCLUSION: The online interdisciplinary intervention improved measures of mental health and emotional wellness suggesting that such interventions may be useful for mental health promotion and prevention. Trial registration The Australian New Zealand Clinical Trials Registry. ACTRN12619000993190. Registered on 12 July 2019 (Retrospectively registered). The ANZCTRN is part of the WHO Primary Registries. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40359-021-00577-8.