Contact

Duke Health News

919-660-1306

DURHAM, N.C . - Racial bias appears to exist in the prescription of antidepressants to the elderly and could signal underdiagnosis or undertreatment of depression in African Americans, a Duke University Medical Center study has found.

The 10-year study of 4,162 elderly adults shows whites are nearly three times more likely to be prescribed antidepressant medications than African Americans, even though the rates of major depression are about equal, the researchers say. That rate jumps to seven times more likely if only prescriptions of selective serotonin reuptake inhibitors (SSRIs) are considered. Those drugs were introduced by the pharmaceutical industry in the last 10 years.

"This study suggests a potential for racial bias in the prescription of medication to the elderly," said Dr. Dan Blazer, a Duke psychiatrist and lead author of the study. "One would assume the prescriptions would be equal by race, especially if the rate of disease is similar in both groups. Other studies have shown that racial differences exist in terms of health care services provided, but the degree we see here is pretty dramatic. These findings were quite unexpected."

Blazer published the results of his study in the July issue of the American Journal of Psychiatry. The National Institute on Aging (NIA) funded the study.

The most likely explanation for the discrepancy appears to be a combination of relative underdiagnosis or undertreatment of depression in elderly African Americans coupled with racially biased prescribing practices, according to the researchers.

Researchers had expected the rate of antidepressant usage to decline as the study sample aged because of the increased risk of interactions between antidepressants and other medications, as well as the expected increase in illnesses that might preclude the use of antidepressants. Nevertheless, the recent availability of SSRIs - which produce fewer side effects - might offset the concerns of physicians who might be reticent to prescribe them, researchers say.

For the entire study sample, the percentage of subjects taking antidepressants increased from 3.8 percent in 1986-87 to 11 percent in 1996-97. When researchers examined the data by race, they discovered the increased use of such medications was largely due to an increase in usage by whites over the 10-year period, even after controlling for income and use of health care services. There is a seven-fold difference in the use of SSRIs when the two racial groups are compared and a three-fold difference in all antidepressant usage in 1996-97. That difference is a marked increase from the two-fold difference that existed in 1986-87.

"Given recent studies, we were not surprised that more elderly subjects used antidepressants," Blazer said. "Antidepressant use has increased, in general, among all age groups since the introduction of SSRIs to the market. However, in this population a seven-fold increase is very surprising and shows a serious racial discrepancy in prescription practices. I think a lot of hard questions need to be asked."

A study published by other Duke researchers in May reported racial biases among physicians appear to exist as early as medical school.

Data for the study were collected using the Duke Established Populations for Epidemiological Studies of the Elderly (EPESE) cohort - a multicenter, collaborative population survey of community-dwelling persons aged 65 and older living in central North Carolina.

Co-authors on the paper were Celia Hybels of Duke, Eleanor Simonsick of the NIA, and Joseph Hanlon of the University of Minnesota.