Depression and mortality among institutionalized aged.

This study examined the association between depression and mortality among a group of nursing home and congregate apartment residents (initial n = 898) over a 30-month period. Baseline [Time 1 (T1)] and 1-year follow-up [Time 2 (T2)] assessments yielded research-based diagnoses of possible major, minor, or no depression, along with measures of functional disability, cognitive status, and physician-rated health. Event history analyses were used to assess differential mortality as a function of level of depression after T1 and of change in depressive status from T1 to T2. Significant effects for T1 depression at 6, 12, and 18 months after the interview reflected an increased death rate among possible major depressives as compared with other respondents. An effect of change in depressive status from T1 to T2 appeared to be caused by long-term negative effects of T1 depression. Finally, none of the observed associations remained significant when controlled for effects of physical health, functional disability, and cognitive status. Thus, the effects of depression on mortality among this sample appeared to be attributable strictly to the correlation of depression with ill health. However, cautious interpretation is recommended inasmuch as causal paths between depression, ill health, and death remain unclear.