In 2013, depression was the second leading cause of years lived with a disability worldwide, behind lower back pain. In 26 countries, depression was the primary driver of disability.
Ref: Ferrari, A.J., Charlson, F.J., Norman, R.E., Patten, S.B., Freedman, G., Murray, C.J.L., … & Whiteford, H.A., (2013). Burden of Depressive Disorders by Country, Sex, Age, and Year: Findings from the Global Burden of Disease study 2010. PLOS Medicine, 10(11).