Studies of the effect of depression on life expectancy have found cont
roversial results. In the past, an excess mortality was attributed to
conditions seen at psychiatric institutions. More recently, in additio
n to an excess mortality due to violent causes of death, some studies
also found excess mortality due to non-violent and all-cause mortality
. Hospital studies that evaluated this relationship are generally flaw
ed and lack of control for potential confounders. Underlying physical
illnesses could explain the excess mortality reported On the other han
d, community-based studies have studied small number of depressed subj
ects, and have used diverse measurements of depression which hamper co
mparability. This paper critically reviews recent published studies an
d discussess posible mechanisms for this association.