Depression is not a normal consequence of growing old. It is, instead, a treatable illness, a source of excess disability, and the major cause of suicide in the elderly. Depression occurs in 2–3% of persons aged 60 and above residing in communities, 8–10% of elderly patients attending general medical clinics, and 20% or more of elderly patients in acute medical hospitals or long-term care facilities.

The World Health Organization has estimated that depression and suicide constitute the fourth leading contributor to the global burden of illness-related disability and death. It expects that the importance of depression as a source of disability and impaired quality of life will increase in the next 10 years, especially in the developed economies, because of the high proportion of elderly persons in the general population.