Background: Children’s mental health is a growing focus in health promotion. Current treatments focus primarily on modifying internal cognitions with insufficient effect on functional outcomes. Occupational therapists can promote health and wellbeing by enabling children to design and build health-promoting routines and make healthy occupational choices. There was no evidence for the use of occupational therapy as an intervention to promote mental health or increase participation and wellbeing in a preventative context. The aim of the current study was to investigate the effectiveness of a preventative occupational therapy group intervention (Kia Piki te Hauora: Uplifting our Health and Wellbeing©) designed to reduce symptoms of anxiety and depression and improve self-esteem and participation in children aged 11-13 years, by completion of the intervention, and the sustainability of any improvements after a follow-up period of 8-9 weeks.

Methods: The study used a pragmatic, cluster-randomised controlled trial design with two arms: intervention and (waitlist) control. The sample size calculated was 126 participants from 14 clusters, based on a conservatively estimated intra-cluster coefficient (ICC) of 0.05 and a design effect (0.81) to account for the clustering and adjusting for covariates in the analyses. Fourteen clusters (schools), equating to 151 participants, were stratified by school decile-rank category and constrained stratified block randomisation was applied. Blinding of participants post-randomisation was not feasible; however, outcomes assessors were blinded. Outcomes were measured at baseline, after the parallel and crossover phases, and at follow-up and were anxiety symptoms (primary), depression symptoms, self-esteem, participation and wellbeing. Data from intervention participants were compared to waitlist-control participants who later went on to receive the intervention: resulting in the crossover phase of the trial. Data were analysed using an intention-to-treat approach to analysis. A mixed design Repeated Measures Analysis of Covariance was conducted to enable adjustment for the clusters and to statistically control for covariates identified. Per protocol, unadjusted and sub-group analyses were also performed.

Results: This trial found significant positive effects of the intervention on child-rated satisfaction with their occupational performance and teacher-rated child anxiety. No evidence was found to support the effect of the intervention on anxiety and depression symptoms, self-esteem and wellbeing. However, there was evidence that the child-rated anxiety and depression symptoms 8-9 weeks after the intervention were no worse and possibly improved as compared to immediately post-intervention.

Discussion: The current study has provided no new evidence to support the theory that participation in meaningful, positive occupations can impact on mental health symptoms. Strengths of the study included a fully pre-specified statistical analysis plan, robust efforts to minimise biases and sufficient sample size. Limitations included not being able to blind participants and personnel, lack of an attention-control intervention and qualitative data collection. Having a short follow-up period and low parent and teacher response rates also limited findings. Recommendations are made to redesign the intervention as an embedded intervention in the classroom, co-taught by teachers and including parental involvement.

Contribution of new knowledge: This was the first known cluster-randomised controlled trial to investigate an occupational therapy intervention promoting emotional wellbeing in a non-clinical sample of children.