Bio-psycho-social risk factors for depression

Major depressive disorder (MDD) is one of the most common psychiatric disorders. In general, 10% to 25% of women and 5% to 10% of men are at risk for having MDD once in their lifetime. In addition, 5% to 10% of the population suffers from MDD, while 3% to 5% of the population is estimated to have severe MDD that requires treatment [1]. According to the Global Burden of Disease (published by the World Health Organization), which considers both mortality and morbidity, MDD ranked fourth place among all diseases. It is expected to rise to second place by 2020 following ischemic heart disease [2]. The most effective way to reduce the burden of MDD is to prevent its onset by first identifying high-risk individuals rather than treating MDD that has already started. MDD prevention includes efforts to remove or reduce MDD risk factors. However, MDD is thought to have multidimensional causes and pathogenesis in terms of bio-psycho-social variables, thus risk factors are complicated. In this paper, the bio-psycho-social risk factors for MDD are summarized.