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


Etiology

Depressive symptoms were associated with an increased risk for stroke mortality

ACP J Club. 1998 Nov-Dec; 129:76. doi:10.7326/ACPJC-1998-129-3-076


Source Citation

Everson SA, Roberts RE, Goldberg DE, Kaplan GA. Depressive symptoms and increased risk of stroke mortality over a 29-year period. Arch Intern Med. 1998 May 25;158:1133-8.


Abstract

Question

What is the association between self-reported depressive symptoms and death from stroke in community-living adults?

Design

29-year cohort study of participants in the Alameda County Study.

Setting

Alameda County, California, United States.

Participants

6676 of 6928 adults (mean age 43 y, 54% women) for whom complete data were available from the Alameda County Study, which began in 1965. Participants were 17 to 94 years of age and did not have a history of stroke at baseline.

Assessment of risk factors

Depression was measured by using the Human Population Laboratory Depression scale. Other risk factors included years of education, alcohol consumption, body mass index, smoking, and self-reported hypertension and diabetes.

Main outcome measure

Stroke mortality was verified by death certificates.

Main results

39 of 969 (4%) participants who reported ≥ 5 depressive symptoms and 130 of 5707 (2%) nondepressed participants died of stroke. Self-reported depressive symptoms were associated with increased stroke mortality in unadjusted analyses (P = 0.003) and in analyses adjusted for age, sex, and race (P = 0.006). The association remained when the results were further adjusted for education, alcohol consumption, smoking, hypertension, diabetes, and body mass index (P = 0.02) (Table). Time-dependent covariate models, which incorporated changes in reported depressive symptoms and risk factor levels during follow-up, showed a similar but nonsignificant association between self-reported depressive symptoms and increased stroke mortality. The association also remained when patients who had cardiovascular disease or who died within the first 3 years were excluded from the analysis.

Conclusion

Self-reported depressive symptoms were associated with an increased risk for stroke mortality in community-living adults.

Source of funding: National Institute on Aging.

For correspondence: Dr. S.A. Everson, Department of Epidemiology, School of Public Health, University of Michigan, 109 South Observatory Street, Ann Arbor, MI 48109-2029, USA. FAX 734-764-3192.


Table. Association between self-reported depressive symptoms and stroke mortality

Depression measure at 29 y Hazard ratio (95% CI)
1-point increase on Human Population Laboratory Depression Scale 1.09 (1.03 to 1.15)
≥ 5 self-reported depressive symptoms 1.54 (1.06 to 2.22)*

*Hazard ratio adjusted for age, race, sex, education, alcohol consumption, smoking, hypertension, diabetes, and body mass index.


Commentary

The association between affective disorders and cardiovascular morbidity and mortality has received increasing attention. Many studies show increased mortality in patients who are depressed after MI, and evidence also indicates an increased cardiovascular risk in depressed patients without known coronary heart disease (CHD). Psychosocial interventions may decrease this risk, and psychotropic medicationtrials are in progress (1).

Depression after stroke is associated with decreased functional outcomes (2), but less evidence exists for an increased risk for stroke in depressed patients. The study by Everson and colleagues provides some evidence of such a link. A recent abstract from the NHAMES I study also suggests a similar effect (3). The strengths of this study are its size, its use of population-based sampling, and its long follow-up period. Its weaknesses, which are acknowledged by the authors, include the use of self-reported measurements and the exclusion of suchfactors as physical activity, degree of hypertension, and lipid levels from analysis. Nevertheless, the effect remained after adjustment for early events related to CHD and the temporal variation of depressive symptoms.

Too much uncertainty exists to justify screening and treating patients for depression solely to prevent stroke. Yet depression is underrecognized by primary care physicians despite the efficacy of simple screening questions (4), and it has a marked effect on quality of life (5). If treating depression can help the patient to feel well, all the better if it can also prevent CHD or stroke.

Craig Redfern, DO
Portland Providence Medical CenterPortland, Oregon, USA


References

1. Musselman DL, Evans DL, Nemeroff CB. The relationship of depression to cardiovascular disease: epidemiology, biology, and treatment. Arch Gen Psychiatry. 1998;55:580-92.

2. Morris PL, Raphael B, Robinson RG. Clinical depression is associated with impaired recovery from stroke. Med J Aust. 1992;157:239-42.

3. Jonas BS, Mussolino M. Are symptoms of anxiety or depression risk factors for incident cases of stroke? [Abstr]. Ann Behav Med. 1998;20:S59.

4. Kroenke K. Discovering depression in medical patients: reasonable expectations. Ann Intern Med. 1997;126:463-5.

5. Spitzer RL, Kroenke K, Linzer M, et al. Health-related quality of life in primary care patients with mental disorders. Results from the PRIME-MD 1000 Study. JAMA, 1995;274:1511-7.