In a review of 852 trials of pharmacotherapies and psychotherapies for major psychiatric disorders, involving 137,126 patients, an international team of researchers found that the effect sizes of these interventions, either separately or in combination, weren’t very impressive. “Many pharmacotherapies and psychotherapies are effective, but there is a lot of room for improvement,” they concluded. They also expressed concern about the lack of quality studies comparing pharmacotherapy and psychotherapy. “Head-to-head trials are scarce, and funding for them is urgently needed,” the researchers wrote in JAMA Psychiatry.
Huhn, Maximilian et al. “Efficacy of Pharmacotherapy and Psychotherapy for Adult Psychiatric Disorders: A Systematic Overview of Meta-analyses” JAMA Psychiatry. 2014;71(6):706-715. doi:10.1001/jamapsychiatry.2014.112
To be honest, I’d really take a look at the methodology of these studies. Throw away all of them where authors declare conflict of interest by taking money from groups which stand to profit from the results one way or the other. Make sure that you’re talking about the same problem (stop using DSM). Make sure you’re not cherry picking data. Etc. and so on…