ABSTRACT
Considerable strides have been made in the past several decades in
understanding the epidemiology of depression. Although the aetiology
of depressive illness remains largely unknown, the risk factors identified
through epidemiologic studies suggest avenues for prevention and for
early intervention, as well as potential directions for aetiologic study. In
this chapter, we will address several basic issues regarding the nature and
distribution of depression in community-based, primary care, and spe-
cialty medical populations. We will consider its association with other
psychiatric disorders and with other health outcomes, including suicide
and mortality from other causes. Finally, we will summarize current
information on key risk factors for depressive illness across the lifespan.
