Depression is a major public health problem, contributing to significant morbidity, disability as well as mortality, along with significant socioeconomic losses. It affects large number of children, adolescents, middle-aged groups and elderly, both men and women, residing in urban, rural areas and slums of India. India is home to an estimated 57 million people (18% of the global estimate) affected by depression. Globally, the total number of people with depression was estimate to exceed 300 million people equivalent to 4.4% in 2015. According to World Health Organization (WHO), Depression is a common mental disorder, characterized by persistent sadness and a loss of interest in activities that you normally enjoy, accompanied by an inability to carry out daily activities, for at least two weeks. In Unani Medical Hippocratic writings (fourth century BC), serious mental illness was ascribed mainly to physical cause, which were represented in the theory that health depended on correct balance of the four body ‘humour’ blood, phlegm, yellow bile, and black bile. Melancholia was ascribed to an excess of black bile.⁸ Melancholia, formerly the psychological condition known as depression. The term now refers to extreme features of depression, especially the failure to take pleasure in activities. Depression is the common cold of mental disorder most people will be affected by depression in their lives either directly or indirectly through a friend or family member. In the classical literatures of Unani System of Medicine, Melancholia is defined as a disease in which there is disturbance of thoughts and intellect. It is characterized by social isolation, loneliness, negative thoughts, mistaken belief, fear of objects by which an average person is not afraid, loss of interest and pleasure in usual activities, hallucination, excessive grief, mainly due to disproportion (excess) of  Sawdā’ or deterioration in the quality of it. Depression is associated with medical illness like cardiovascular diseases, diabetes mellitus, cancer, neurologic disorders, hypothyroidism etc. The life time prevalence of depression in HIV present individuals has been estimate at 22-45%.