Psychotherapies are popular complementary treatments. These treatments include behavioral activation therapy (BA), cognitive behavior therapy (CBT), problem-solving therapies (PST), and self-examination therapy (SET); “third-wave” therapies such as acceptance and commitment therapy (ACT), mindfulness-based CBT (MBCT), cognitive behavioral analysis system of psychotherapy (CBASP), and dialectic therapy (DBT); as well as interpersonal psychotherapy (IPT), psychodynamic therapy, non-directive supportive therapy, life review therapy, exposure therapy, and eye movement desensitization and reprocessing (EMDR). This chapter presents the results of recent meta-analyses investigating the evidence for the efficacy of 15 psychotherapies for depression. Progress in the field is hampered by methodological problems including the abundance of studies with small sample sizes and insufficient power to detect differences between treatments. Several sources of bias have been reported, including strong researcher allegiance to the therapy, non-blinding of raters, improper randomization, selective outcome reporting, publication bias, waiting list control groups, problems with meta-analysis, and the placebo effect. The “Dodo bird verdict” contends that meta-analyses have been unable, so far, to find any significant difference between psychotherapeutic techniques, suggesting that they are all equally effective. The common factors theory proposes that treatment differences, the therapist’s competence, specific ingredients, and protocol adherence are not responsible for the outcome of psychotherapies. But factors common to all psychotherapies: foremost are the personality traits of the psychiatrist or psychotherapist such as genuineness and empathy. Further commonalities include goal consensus, collaboration, alliance, positive regard, and affirmation.