Background: The National Institutes of Mental Health's (NIMH) 1985 Treatment of Depression Collaborative Research Program (TDCRP) reported that imipramine hydrochloride with clinical management (IMI-CM) was significantly more beneficial than placebo with clinical management (PLA-CM) for individuals undergoing treatment for depression. Unfortunately, in analyzing the NIMH TDCRP data, researchers ignored the potential effect that psychiatrists have on patient outcomes, thereby assuming that psychiatrists are equally effective. However, this assumption has yet to be supported empirically. Therefore, the purpose of the current study is to examine psychiatrist effects in the NIMH TDCRP study and to compare the variation among psychiatrists to the variation between treatments.
Method: Data from 112 patients [IMI-CM (n = 57, 9 psychiatrists); PLA-CM (n = 55, 9 psychiatrists)] from the NIMH TDCRP study were reanalyzed using a multi-level model.
Results: The proportion of variance in the BDI scores due to medication was 3.4% (p < .05), while the proportion of variance in BDI scores due to psychiatrists was 9.1% (p < .05). The proportion of variance in the HAM-D scores due to medication was 5.9% (p < .05), while the proportion of variance in HAM-D scores due to psychiatrist was 6.7% (p = .053). Therefore, the psychiatrist effects were greater than the treatment effects.
Conclusions: In this study, both psychiatrists and treatments contributed to outcomes in the treatment of depression. However, given that psychiatrists were responsible for more of the variance in outcomes it can be concluded that effective treatment psychiatrists can, in fact, augment the effects of the active ingredients of anti-depressant medication as well as placebo.