Researchers from the VU University Amsterdam analyzed primary data submitted by the authors of 16 randomized, controlled trials in which CBT was compared with pharmacotherapy among outpatients with a primary diagnosis of a depressive disorder (major depressive disorder or dysthymia). Main outcome measures included improvements in scores on the 17-item Hamilton Rating Scale for Depression (HAM-D) and Beck Depression Inventory (BDI), as well as the rates of response and remission.
Based on their analysis, the researchers identified a modest (less than 1 point) main effect of antidepressant pharmacotherapy over CBT on the HAM-D and a nonsignificant trend on the BDI, but no significant differences in rates of response (defined as 50% reduction in scores on post-test HAM-D) or remission. Additional analysis indicated that baseline depression severity does not moderate reductions in depressive symptoms between CBT and antidepressant medications.
The authors wrote that while their analysis “shows that pharmacotherapy provides minor improvement in the treatment of depression relative to CBT in terms of the continuous measures, there is no indication that differences between the modalities were moderated by the degree of baseline depression severity. Therefore, the data are insufficient to recommend [antidepressant medications] over CBT in outpatients based on baseline severity alone,” the authors wrote. “More research is needed to examine whether other demographic and clinical characteristics moderate the differential response between CBT and [antidepressant medications].”
A senior author on this paper previously investigated treatment response differences among racial and ethnic groups, as reported in the Psychiatric Services article "The Effects of Psychotherapy on Depression Among Racial-Ethnic Minority Groups: A Metaregression Analysis."