Most psychotherapies for depression have been developed in high-income Western countries of North America, Europe and Australia. A growing number of randomized trials have examined the effects of these treatments in non-Western countries. We conducted a meta-analysis of these studies to examine whether these psychotherapies are effective and to compare their effects between studies from Western and non-Western countries. We conducted systematic searches in bibliographical databases and included 253 randomized controlled trials, of which 32 were conducted in non-Western countries. The effects of psychotherapies in non-Western countries were large (g=1.10; 95% CI: 0.91-1.30), with high heterogeneity (I2 =90; 95% CI: 87-92). After adjustment for publication bias, the effect size dropped to g=0.73 (95% CI: 0.51-0.96). Subgroup analyses did not indicate that adaptation to the local situation was associated with the effect size. Comparisons with the studies in Western countries showed that the effects of the therapies were significantly larger in non-Western countries, also after adjusting for characteristics of the participants, the treatments and the studies. These larger effect sizes in non-Western countries may reflect true differences indicating that therapies are indeed more effective; or may be explained by the care-as-usual control conditions in non-Western countries, often indicating that no care was available; or may be the result of the relative low quality of many trials in the field. This study suggests that psychotherapies that were developed in Western countries may or may not be more effective in non-Western countries, but they are probably no less effective and can therefore also be used in these latter countries.
Keywords: Depression; care-as-usual; low- and middle-income countries; meta-analysis; psychotherapy.
© 2018 World Psychiatric Association.