Psychological treatment of depression: a systematic overview of a 'Meta-Analytic Research Domain'

Background: Over the past 16 years, we have developed a 'Meta-analytic Research Domain' (MARD) of all randomized trials of psychological treatments of depression. A MARD is a living systematic review of a research field, that cannot be otherwise covered by one (network) meta-analysis and includes multiple PICOs. In this paper we give an overview of the findings of this MARD. Methods: A narrative review of the results of the 118 meta-analyses on psychotherapies for depression that were published within our MARD. Results: Most research has been conducted on cognitive-behavioral therapy (CBT), but several other psychotherapies are also effective, with few differences between therapies. They can be effectively delivered in individual, group, telephone and guided self-help format and are effective in many different target groups and across different age groups, although the effects are significantly smaller in children and adolescents. Psychotherapies have comparable effects as pharmacotherapy at the short term but are probably more effective at the longer term. Combined treatment is more effective than either psychotherapy or pharmacotherapy alone at the short, but also at the longer term. Limitations: We did not summarize all published meta-analyses (protocols, methodological studies) and have not compared our results to those found in other meta-analyses on comparable subjects. Conclusion: Psychotherapies can contribute considerably to a reduction of the disease burden of depression. MARDs are an important next step in the aggregation of knowledge from randomized controlled trials in psychological treatments of depression as well as in other healthcare sectors.