The equivalence of psychodynamic therapy and cognitive behavioral therapy for depressive disorders in adults: A meta-analytic review

Background

Meta-analyses on the relative efficacy of psychodynamic psychotherapy (PDT) and cognitive behavioral therapy (CBT) for depressive disorders are limited by heterogeneity in diagnostic samples and comparators and a lack of equivalence testing.

Objective

We addressed this through a meta-analytic test of the equivalence of manualized PDT and CBT in treating adults with depressive disorders as determined by diagnostic interviews. Sensitivity analyses evaluated the impact of pretreatment differences, mixed diagnostic samples, author allegiance, study quality, year of publication and outliers on findings.

Method

A comprehensive literature search across multiple databases using reliable screening methods identified nine randomized controlled trials directly comparing manualized PDT and CBT for diagnosed depressive disorders in adults. Following pre-registration, we employed random effect models for our meta-analyses and two one-sided test procedures for equivalence testing.

Results

Independent raters determined that all studies were of adequate quality. Immediately posttreatment, depressive symptoms were statistically equivalent across PDT and CBT (k = 9; g = −0.11, 90% confidence interval [90% CI]: −0.24 to 0.02, p_equivalence = .048, p_NHST = .212, I² = 32.7). At follow-up, the longest time point within a year, depressive symptoms were neither statistically equivalent nor statistically different (k = 6; g = −0.16, 90% CI: −0.31 to −0.02, p_equivalence = .184, p_NHST = .126, I² = 0.00).

Conclusion

The efficacy of manualized PDT is equal to manualized CBT immediately at posttreatment for depressive disorders in the adult general population. Nevertheless, insufficient data exists to reach a conclusion regarding equivalence at follow-up.