In the past four decades several hundreds of randomized trials have examined the effects of psychotherapy for adult depression. In this presentation the results of a series of meta-analyses of these trials will be presented. These results are based on more than 30 published metaanalyses that have used a meta-analytic database of these trials (www.evidencebasedpsychotherapies.org). First, the results of a meta-analysis of 19 trials on prevention of the incidence of depressive disorders will be presented. This meta-analysis has shown that preventive interventions can significantly reduce the incidence of new cases of depressive disorders with 22%. Studies on psychological treatments of adult depression (N=315) have found relatively large effect sizes (d > 0.6) for these treatments in general. These studies also show that the effects of psychotherapy are comparable with those of pharmacotherapy and that combined treatments are more effective than psychotherapy alone or pharmacotherapy alone. There are no big differences between the different types of psychotherapy. Interpersonal psychotherapy may be somewhat more effective and non-directive supportive therapy may be somewhat less effective than other therapies, but these differences are small and not consistent. Psychotherapies are effective in several more specific target groups, including older adults, women with postpartum depression, and patients with general medical disorders. Effect sizes are smaller in chronic depression and dysthymia, and in inpatients. The effects of psychotherapy are probably overestimated because of the low quality of many studies in this research area, and because of publication bias.