Improving Access to Psychological Therapies (IAPT) in the United Kingdom: A systematic review and meta-analysis of 10-years of practice-based evidence.

OBJECTIVES: Improving Access to Psychological Therapies (IAPT) is a national-level dissemination programme for provision of evidence-based psychological treatments for anxiety and depression in the United Kingdom. This paper sought to review and meta-analyse practice-based evidence arising from the programme. DESIGN: A pre-registered (CRD42018114796) systematic review and meta-analysis. METHODS: A random effects meta-analysis was performed only on the practice-based IAPT studies (i.e. excluding the clinical trials). Subgroup analyses examined the potential influence of particular methodologies, treatments, populations, and target conditions. Sensitivity analyses investigated potential sources of heterogeneity and bias. RESULTS: The systematic review identified N = 60 studies, with N = 47 studies suitable for meta-analysis. The primary meta-analysis showed large pre-post treatment effect sizes for depression (d = 0.87, 95% CI [0.78-0.96], p < .0001) and anxiety (d = 0.88, 95% CI [0.79-0.97], p < .0001), and a moderate effect on functional impairment (d = 0.55, 95% CI [0.48-0.61], p < .0001). The methodological features of studies influenced ESs (e.g., such as whether intention-to-treat or completer analyses were employed). CONCLUSIONS: Current evidence suggests that IAPT enables access to broadly effective evidence-based psychological therapies for large numbers of patients. The limitations of the review and the clinical and methodological implications are discussed. PRACTITIONER POINTS: IAPT interventions are associated with large pre-post treatment effect sizes in depression and anxiety measures. IAPT interventions are associated with moderate treatment effect sizes with regards to work and social adjustment. A reduction in dropout and also the prevention of post-treatment relapse via the offer of follow-up support are important areas for future development.

Identifying the Underlying Mechanisms of Change During Acceptance and Commitment Therapy (ACT): A Systematic Review of Contemporary Mediation Studies.

BACKGROUND: Mediation studies test the mechanisms by which interventions produce clinical outcomes. Consistent positive mediation results have previously been evidenced (Hayes et al., 2006) for the putative processes that compromise the psychological flexibility model of acceptance and commitment therapy (ACT). AIMS: The present review aimed to update and extend the ACT mediation evidence base by reviewing mediation studies published since the review of Hayes et al. (2006). METHOD: ACT mediation studies published between 2006 and 2015 were systematically collated, synthesized and quality assessed. RESULTS: Twelve studies met inclusion criteria and findings were synthesized by (a) the putative processes under investigation, and (b) the outcomes on which processes were tested for mediation. Mediation results were found to be generally consistent with the psychological flexibility model of ACT. However, studies were limited in methodological quality and were overly focused on a small number of putative processes. CONCLUSIONS: Further research is required that addresses the identified methodological limitations and also examines currently under-researched putative processes.