Delivering Acceptance and Commitment Therapy (ACT) for mental health disorders across group and guided self-help formats: a meta-analysis and randomised controlled trial

Abstract

Background: Acceptance and Commitment Therapy (ACT) has shown promise as an effective intervention in the treatment of mental health disorders. In the last decade, the delivery of ACT has expanded to include various formats (e.g. groups, self-help, online and phone apps). Further research is needed to evaluate whether such delivery formats are a viable extension of ACT. Furthermore, the existing evidence base of certain alternative delivery formats have yet to be reviewed. This thesis portfolio sought to contribute to this area of research. Methods: A systematic review of the literature was conducted to investigate the efficacy of group-based interventions for mental health disorders using ACT. Five databases were systematically searched, manual searches were conducted and corresponding authors were contacted. Studies which used a randomised-controlled design, with adult samples and investigated group-based ACT interventions for mental health disorders were included. A meta-analysis of the included studies was conducted for post-intervention and follow-up data. In the empirical study, an ACT manual was trialled using a randomised-controlled design to investigate the efficacy of using ACT in a guided self-help context. Participants with anxiety/depression were randomly assigned to receive either the ACT intervention or treatment as usual (TAU). Those in the ACT group were posted an ACT manual and received two telephone calls. Outcome measures were analysed after the six-week intervention. Results: From the meta-analysis, 18 randomised-controlled trials were identified, 14 of which focussed on anxiety and depression. The findings suggest that ACT-based groups have a large effect on symptom reduction when compared to non-active comparisons at post-treatment and a moderate effect when compared to non-active comparisons at follow-up. Additionally, there was a small effect in favour of ACT when compared to active treatment controls at post-treatment and equivalent effects when comparing ACT to active treatment controls at follow-up. Similar effects were found when separately comparing the 14 studies which focussed primarily on anxiety and depression. The empirical study revealed that guided self-help was found to be no more effective in improving quality of life or reducing psychological distress than the TAU group. However, such results should be interpreted with caution as the small sample size and high attrition rate indicates that further research with larger samples and follow-up are needed before strong conclusions can be made. Conclusions: The findings of this research indicate that group-based ACT interventions may be a suitable alternative delivery format for service providers in the provision of common mental health disorders, particularly anxiety and depression. Further research is needed before any strong conclusions can be made regarding the efficacy of guided self-help for anxiety/depression.