Twelve studies were included (658 participants). Quality criteria adequately addressed by most studies were incomplete outcome data, selective outcome reporting and blinding of outcome assessors. Sequence generation and allocation concealment were the most inadequately addressed criteria.
At immediate post-intervention follow-up cognitive behavioural therapy was significantly and modestly more effective at reducing anxiety symptoms than non-active control (treatment as usual or being on a waiting list; seven studies). Between-group difference in effect size with active control was not statistically significant, and the effect size was small. There was no significant heterogeneity at six months, but not three or 12 month follow-up, cognitive behavioural therapy was significantly more effective at reducing anxiety symptoms than an active control (four studies), but the effect size was small. There was no significant heterogeneity at six month follow-up; moderate heterogeneity was found at 12-month follow-up.
Cognitive behavioural therapy was significantly and modestly more effective at reducing depression symptoms than treatment as usual or being on a waiting list at immediate post-intervention follow-up alone (six studies); but there were no significant differences with an active control, or any time points beyond.
No evidence of publication bias was found. Results of the meta-regression analysis were reported.