Eight studies (875 participants) were included in the review. All studies were randomised and assessors were unaware of treatment allocation. Five studies performed intention-to-treat analyses. Two studies retained all their patients. Completers' data were reported in one study. Follow-up ranged from 28 weeks after randomisation to six years after treatment.
Compared to control, sequential use of psychotherapy was associated with a significantly lower risk of relapse or recurrence (RR 0.80, 95% CI 0.66 to 0.96; eight studies with no significant heterogeneity). Sensitivity analyses indicated that one study changed the results to a non-significant trend that favoured sequential psychotherapy. Meta-regression suggested that continuation versus tapering of pharmacotherapy, different types of psychotherapy and different duration of treatment did not markedly influence results.
Subgroup analyses: Compared to continuation of antidepressant medication or treatment as usual, psychotherapy during continuation of antidepressants was associated with a non-significant trend in reducing relapse or recurrence (RR 0.84, 95% CI 0.67 to 1.05; five studies with no significant heterogeneity). Compared to continuation of antidepressants or clinical management, continuation phase psychotherapy while antidepressants were discontinued was associated with significantly lower rates of relapse or recurrence (RR 0.65, 95% CI 0.46 to 0.91, I2=52%; three studies with no significant heterogeneity).
There was no evidence of publication bias in any of the analyses.