Current issues of ACP Journal Club are published in Annals of Internal Medicine


Etiology

Depressive symptoms were associated with increased mortality in older women

ACP J Club. 1999 May-June;130:78. doi:10.7326/ACPJC-1999-130-3-078


Source Citation

Whooley MA, Browner WS, for the Study of Osteoporotic Fractures Research Group. Association between depressive symptoms and mortality in older women. Arch Intern Med. 1998 Oct 26;158:2129-35.


Abstract

Question

Is there an association between depressive symptoms and mortality in older women?

Design

Community-based, cohort study of participants in the Study of Osteoporotic Fractures with a mean follow-up of 6 years.

Setting

United States (Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; and Monongahela Valley, Pennsylvania).

Participants

7518 of 9704 ambulatory women who were ≥ 65 years of age (mean age 72 y) and were recruited from population-based listings.

Assessment of risk factors

Depression was assessed with the Geriatric Depression Scale (short form). Potential confounding variables (age; marital status; living alone; education; medical history; perceived health status; smoking; alcohol use; use of benzodiazepines, barbiturates, thiazide diuretics, and estrogen; blood pressure; physical activity; body mass index [BMI]; social support; and cognitive function) were also assessed.

Main outcome measures

Mortality was confirmed by death certificates and hospital records. 1 author, who was blinded to risk factor data, classified the cause of death.

Main results

Women with ≥ 6 depressive symptoms were more likely to be older, unmarried, less educated, and physically inactive; to smoke; to report fair or poor health; and to have medical illnesses, worse functional status, impaired cognitive function, and a greater BMI than were women with ≤ 5 depressive symptoms. More deaths occurred in women with ≥ 6 depressive symptoms than in women with ≤ 5 depressive symptoms (24% vs 11%, age-adjusted hazard ratio 2.14, 95% CI 1.75 to 2.61, P < 0.001). After further adjustment for potential confounding variables, the association remained (P = 0.003) (Table). Women with depressive symptoms had an increased risk for death from cardiovascular disease (P = 0.003) and from noncancer and noncardiovascular conditions (P = 0.01) but not for death from cancer (P = 0.93) (Table).

Conclusion

Depressive symptoms were associated with an increased risk for death from all causes, death from cardiovascular disease, and death from noncardiovascular and noncancer conditions in older women.

Source of funding: U.S. Public Health Service.

For correspondence: Dr. M. A. Whooley, General Internal Medicine Section, San Francisco Veterans Affairs Medical Center, 4150 Clement Street, 111A1, San Francisco, CA 94121, USA. FAX 415-386-4044.


Table. Association between ≥ 6 depressive symptoms and death at 6 years in older women

Cause of death Adjusted hazard ratio* (95% CI)
All causes 1.47 (1.14 to 1.88)
Cardiovascular disease 1.8 (1.2 to 2.5)
Noncardiovascular and noncancer conditions 1.8 (1.2 to 2.7)
Cancer 1.0 (0.6 to 1.7)†

*Adjusted for age, history of myocardial infarction or stroke, chronic obstructive pulmonary disease, hypertension, diabetes, smoking, perceived health, and cognitive function.
†Not significant.


Commentary

The prospective cohort study by Whooley and colleagues was large enough to strengthen support for a previously described association between depressive symptoms and increased mortality. Another study found an association between depression and death from coronary heart disease in elderly women but not in men (1). The large number of participants in the current study allowed the authors to adjust for many potentially confounding variables; however, this study was limited to white women. The statistical adjustments help to address the vexing problem that an association between chronic illness and depression might account for the association between depression and mortality. In this study, the association between depressive symptoms and mortality was weaker than that reported in other studies but remained statistically significant after adjustment for the presence of chronic illnesses. Despite recent studies that showed an association between depressive symptoms and cancer incidence in the elderly (2), death from cancer was not increased in this study.

The presence of an association does not prove a causal relation. No evidence exists to show that treating depression reduces mortality. Nevertheless, strong evidence supports other reasons to aggressively treat depression in older persons (3). The association between the presence of depressive symptoms and increased mortality further supports a link between emotion and resistance to disease.

Jay S. Luxenberg, MD
Jewish Home for the AgedSan Francisco, California, USA


References

1. Mendes de Leon CF, Krumholz HM, Seeman TS, et al. Depression and risk of coronary heart disease in elderly men and women: New Haven EPESE, 1982-1991. Established Populations for the Epidemiologic Studies of the Elderly. Arch Intern Med. 1998;158:2341-8.

2. Penninx BW, Guralnik JM, Pahor M, et al. Chronically depressed mood and cancer risk in older persons. J Natl Cancer Inst. 1998;90:1888-93.

3. Schneider LS, Olin JT. Efficacy of acute treatment for geriatric depression. Int Psychogeriatr. 1995;7 (Suppl):7-25.