July 12, 1998
Men with clinical depression are more than twice as likely to develop coronary artery disease (CAD) as their non-depressed counterparts, a Johns Hopkins study has shown.
"Clinical depression appears to be an independent risk factor for coronary artery disease, even several decades after the first episode," says Daniel E. Ford, M.D., M.P.H., lead author of the study and an associate professor of medicine, epidemiology and health policy and management at Hopkins. "When we accounted for traditional risk factors for CAD, such as high cholesterol, cigarette smoking, hypertension and diabetes, depression remained a statistically significant cause."
Results of the study, supported by the National Institute of Aging, were published in the July 13 issue of the Archives of Internal Medicine.
Ford and his colleagues analyzed data from the Johns Hopkins Precursors Study, a long-term investigation of 1,190 male medical students who were enrolled at Hopkins between 1948 and 1964 and who continue to be followed. In medical school and through the follow-up period, information on family history, health behaviors and clinical depression was collected.
After 40 years of follow-up, 12 percent of the former students reported suffering at least one episode of clinical depression. Those who reported clinical depression were 2.12 times more likely to develop coronary artery disease or suffer a heart attack than their non-depressed counterparts. On average, symptoms of CAD appeared about 15 years after the first episode of depression.
The men who developed clinical depression drank more coffee at the study's outset than those who did not but did not differ from their counterparts in terms of blood pressure, cholesterol, cigarette smoking, physical activity, obesity or family history of CAD.
A minority (23 percent) reported no treatment for clinical depression, with 33 percent reporting use of antidepressant medications and 44 percent reporting psychotherapy with or without use of benzodiazepines or other sedatives. Treatment for depression did not necessarily lower the men's risk of developing CAD, Ford says, but those who were treated may have been more severely depressed initially.
During follow-up, participants with clinical depression were more likely to continue smoking, but this did not account for the increased risk of CAD. For the small number of women in the study, clinical depression also was a risk factor for CAD.
The study's other authors were Lucy A. Mead, Sc.M.; Patricia P. Chang, M.D.; Lisa Cooper-Patrick, M.D., M.P.H.; Nae-Yuh Wang, M.S.; and Michael J. Klag, M.D., M.P.H. All faculty members of The Johns Hopkins University schools of Medicine or Public Health, they work together in Hopkins' Welch Center for Prevention, Epidemiology and Clinical Research.