Introduction Cognitive behavioural therapy has been shown to improve depressive symptoms in adults with mild to moderate depression. To overcome many of the barriers associated with delivering this treatment, attempts have been made to deliver cognitive behavioural therapy via the Internet. The objective of this meta-analysis is to assess whether Internet-based cognitive behavioural therapy delivered to adults with depressive symptoms leads to a reduction in these symptoms as compared to those who receive no therapy. Methods In September 2015, the Cochrane, PubMed and PsycInfo databases were searched; studies were also found through bibliography searches. Studies were included if they were randomized controlled trials published in English between 2005-2015 conducted with adults >18 years of age experiencing mild to moderate depression where study subjects received Internet-based cognitive behavioural therapy, and the control group was placed on a wait-list. The search yielded 257 articles; 14 of these were included in the meta-analysis. Results Internet delivered cognitive behavioural therapy had a medium effect on reducing depressive symptoms at the end of the study period (standardized mean difference: 0.74, confidence interval: 0.62-0.86, p < 0.001). Internet-delivered cognitive behavioural therapy also has a large sustained effect in maintaining reduction of depressive symptoms in follow-up measures done 3-6 months after the conclusion of the therapy (standardized mean difference: 0.83, confidence interval: 0.69-0.99, p < 0.001). There was no publication bias and low heterogeneity. Discussion Cognitive behavioural therapy delivered over the Internet leads to immediate and sustained reduction in depressive symptoms; thus, it may be a good treatment modality for individuals unable or unwilling to access traditional face-to-face therapy.
Keywords: Cost-effectiveness; online health; telemedicine.