This report provides a comprehensive overview of depression, a significant mental illness. It begins by defining depression and its clinical manifestations, including symptoms in adults, children, and older adults. The report delves into the psychopathology of depression, exploring biochemical causes and the role of neurotransmitters. It then discusses the use of psychopharmacology, specifically antidepressant medications, and details the patient education necessary regarding these medications, including side effects and expected timelines for improvement. Furthermore, the report outlines various treatment options, including psychotherapy (such as interpersonal therapy and cognitive behavioral therapy) and electroconvulsive therapy (ECT), highlighting their roles in managing depression. The report concludes by summarizing the key findings and emphasizes the multifaceted approach required for effective depression management.