OBJECTIVE: To determine whether depressive symptoms measured at baseline are associated with mortality and to describe the course of
depressive symptoms and their relation to physical decline in patients over a 6-year period.
DESIGN: Prospective cohort study conducted from 1990 through 1996.
SETTING: Urban academic primary care group practice.
PATIENTS: A cohort of 3,767 patients aged 60 years and older screened for depressive symptoms during routine office visits using the
Centers for Epidemiologic Studies Depression Scale (CES-D) participated in the mortality study. A subsample of 300 patients
with CES-D scores 16 or above and a subsample of 100 patients with CES-D scores less than 16 participated in the study of
the course of depressive symptoms and physical decline.
MEASUREMENTS AND MAIN RESULTS: Mortality by December 1995 was measured for all screened patients; reinterviewed patients completed the CES-D and the Sickness
Impact Profile (SIP). The mean follow-up period was 45 months (± SD 12.2 months); 561 (14.9%) of the patients died by December
1995. In proportional hazards models, age, gender, race, history of smoking, serum albumin value, and an ideal body weight
in the lowest 10% were significant correlates of time to death, but the baseline CES-D was not. Patients with depressive symptoms
had significantly worse physical and psychosocial functioning scores on the SIP than did patients without depressive symptoms.
Using the generalized estimating equation method, the strongest predictor of the current CES-D score was the patient’s prior
CES-D score. However, worsening physical functioning score on the SIP was also independently correlated with worse CES-D scores
(p ≤ .001).
CONCLUSIONS: Symptoms of depression were not associated with mortality in this cohort of older adults. However, patients with depressive
symptoms reported greater functional impairment than did those without depressive symptoms. Moreover, decline in physical
functioning was independently correlated with a concurrent increase in depressive symptoms.
Key words late-life depression - mortality - symptoms - functional impairment
The opinions expressed herein are solely those of the authors and not necessarily those of the supporting institutions and
agencies.
Dr. Callahan was supported by grant K08 AG00538-04 from the National Institute of Health and a Paul Beeson Physician Faculty
Scholar in Aging Research Award. Dr. Wolinsky was supported by grant R37 AG09692 from the National Institutes of Health. Dr.
Tierney was supported by grants HS07632 and HS07763 from the Agency for Health Care Policy and Research.