Major depressive disorder is one of the most common psychological disorders in the general population and among psychiatric patients, and is often accompanied by significant symptoms and impaired function. The results of epidemiological studies have reported depression as the most common psychiatric disorder. In such a way that from every 100 people, approximately 13 males and 21 women suffer from this disorder during a period of their life. Considering the importance of depression disorder and the need for people's awareness about this disorder and attempting to control and treat it in this descriptive-analytical study and by using library resources we aimed to investigate the major depressive disorder and address cases such as the features of the mentioned disorder, its etiology, various perspectives on depression and its treatment methods. It is hoped that the contents of this research will make people aware of this disorder and try to cure it.
