DISCUSSIONIn this study, we aimed to establish the most up-to-date and accurate estimate of the effects of CBT in the treatment of MDD, GAD, PAD and SAD. We also aimed to examine whether the problems of publication bias, low quality of trials, and the use of waiting list control groups have an impact on the effect sizes. We found that the overall effects for all four disorders were large, ranging from g50.75 for MDD to g50.80 for GAD, g50.81 for PAD, and g50.88 for SAD.