The Efficacy and Acceptability of Third-Wave Behavioral and Cognitive eHealth Treatments: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

eHealth is an innovative method of delivering therapeutic content with the potential to improve access to third-wave behaviural and cognitive therapies. This systematic review and meta-analysis aimed to determine the efficacy and acceptability of third-wave eHealth treatments in improving mental health outcomes. A comprehensive search of electronic bibliographic databases including PubMed, PsycINFO, Web of Science, and CENTRAL was conducted to identify randomized controlled trials of third-wave treatments in which eHealth was the main component. Twenty-one studies were included in the review. Meta-analyses revealed that third-wave eHealth significantly outperformed inactive control conditions in improving anxiety, depression, and quality-of-life outcomes and active control conditions in alleviating anxiety and depression with small to medium effect sizes. No statistically significant differences were found relative to comparison interventions. Findings from a narrative synthesis of participant evaluation outcomes and meta-analysis of participant attrition rates provided preliminary support for the acceptability of third-wave eHealth. Third-wave eHealth treatments are efficacious in improving mental health outcomes including anxiety, depression, and quality of life, but not more so than comparison interventions. Preliminary evidence from indices of participant evaluation and attrition rates supports the acceptability of these treatments.