The effect of internet-delivered cognitive behavioral therapy for depression and anxiety on quality of life: A meta-analysis of randomized controlled trials

Although numerous studies have examined the effects of internet-delivered cognitive behavioral therapy (iCBT) for depression and anxiety on quality of life, no meta-analysis has yet been conducted to integrate the results of these studies. We conducted systematic searches in PubMed, Cochrane, and PsycInfo, which included terms for treatment type, modality of delivery, condition, and main outcome. We included studies that met the following inclusion criteria: (a) randomized controlled trials, (b) patients allocated to some form of the control condition, (c) patients receiving some type of treatment of anxiety and/or depression involving Internet-delivered Cognitive Behavioral Therapy, (d) use of a validated outcome measure assessing the level of quality of life, (e) conducted with adult participants diagnosed with anxiety disorder and/or unipolar depression, (f) papers written in English. We analyzed 40 randomized controlled trials with a total of 4289 participants that met inclusion criteria. The pooled between-group effect size for the quality of life overall score was small (g = 0.35, 95 % CI: 0.26-0.44, p = .0001), favoring iCBT over the control conditions. Regarding the distinct quality of life domains measured by the World Health Organization Quality of Life Assessment, a statistically significant difference between iCBT and control conditions was found only for the physical health domain (g = 0.56, 95 % CI: 0.06-1.07, p = .029), in favor of iCBT. In both cases, heterogeneity was moderate. While the effect on the quality of life is small (the overall quality of life score) to moderate (the physical health domain score), we conclude that iCBT for depression and anxiety may be a promising approach for improving the quality of life of patients.