The epidemiology of depressive states in the elderly: implications for recognition, intervention and prevention.

The evidence is reviewed on factors that might affect the onset of new depressive symptoms (destabilization) or loss of depressive symptoms (restitution) in the elderly. These factors are grouped into three broad categories: health-related factors (physical ill health, disability, and dementia and cognitive impairment); social factors (living in a nursing home, social support, bereavement, caring for a disabled person); and personal vulnerability factors (level of depressive symptoms at previous time points, history of depression, personality). The possible implications for preventing destabilization, aiding restitution and identifying high-risk groups are considered. Many of the factors are not easily modifiable, but there is potential for intervention with the physically ill and care givers. The physically ill may also merit routine screening. As in younger age groups, the greatest and most difficult challenge is to modify personal vulnerability.