Depression is largely experienced in our societies. It is costly and highly prevalent medical condition having a lifetime prevalence of around 16% in US adults. Around 13.5 million adults got major depressive disorder in the last year and 34 million will get it at some point. Women experience it more likely about 1.5 to 3 times greater than men. Anyone can experience it at any age but most people experiences first episode in their early thirties. This review represents different factors that are associated with depression