Can coffee stave off depression?

A study supported by the National Institutes of Health (NIH) suggests women who drink several cups of caffeinated coffee each day are at less risk for depression than those who consume one cup or less or drink decaf.

As reported in Archives of Internal Medicine, Michel Lucas, Ph.D., and colleagues from the Harvard School of Public Health in Boston studied 50,739 female participants in the Nurses' Health Study. (The Nurses' project, launched in 1976 with NIH funding, is among the largest ongoing study involving women's health issues.) Average age of the women was 63.

None of the women had been diagnosed with clinical depression at the start of the coffee study, which began in 1996 and ran into 2006. Questionnaires were used to determine individual intake of caffeinated and decaf coffee, tea, soft drinks, and chocolate.

According to the report, 2,607 new-onset cases of depression were identified among participants. After analyzing questionnaire data, researchers found that women who drank two to three cups of caffeinated coffee per day were at 15 percent less risk for depression than women who drank only one cup or less.

Women who drank four cups of caffeinated coffee daily decreased their risk of depression by 20 percent. Drinking decaf coffee did not lower depression risk.

However, researchers note the observational study "cannot prove that caffeine or caffeinated coffee reduces the risk of depression, but only suggests the possibility of such a protective effect." They say more study is needed to better understand the matter.