This issue discusses the diagnosis and treatment of major depressive disorder (MDD) and other depressive disorders, with an emphasis on the psychosocial aspects of depression: how it affects societies, how it is affected by culture, and what the true meaning of recovery is for those suffering from MDD. The issue is divided into three section: Etiology, Diagnosis and Treatment. Authors address the evidence where biology and subjectivity meet. They discuss what is adaptive and what is pathologic and discuss population-based solutions that take into account the specificity of the individual. Authors also take into account combination treatments of psychotherapy and pharmacotherapy and weigh the treatment choices against specific patient subtypes.