A new research initiative explored caffeine’s potential to reduce depression in women.

Depression is a chronic and recurrent condition that affects twice as many women as men, including approximately one of every five U.S. women during their lifetime.

As such, the “identification of risk factors for depression among women and the development of new preventive strategies are, therefore, a public health priority,” write the authors.

In the study, investigators sought to examine whether, in women, consumption of caffeine or certain caffeinated beverages is associated with the risk of depression.

Michel Lucas, Ph.D., R.D., from the Harvard School of Public Health, Boston, and colleagues studied 50,739 U.S. women who participated in the Nurses’ Health Study.

Participants, who had a mean (average) age of 63, had no depression at the start of the study in 1996 and were followed up through June 2006.

Researchers measured caffeine consumption through questionnaires completed from May 1980 through April 2004, including the frequency that caffeinated and noncaffeinated coffee, nonherbal tea, caffeinated soft drinks (sugared or low-calorie colas), caffeine-free soft drinks (sugared or low-calorie caffeine-free colas or other carbonated beverages) and chocolate were usually consumed in the previous 12 months.

For the investigation, depression was identified by a new diagnosis of clinical depression and beginning regular use of antidepressants in the previous two years.

Researchers discovered the risk for depression was less for women consuming four cups or more per day (a 20 percent decrease) and by those who consumed two to three cups per day (a 15 percent decrease).

Compared with women in the lowest (less than 100 milligrams [mg] per day) categories of caffeine consumption, those in the highest category (550 mg per day or more) had a 20 percent decrease in relative risk of depression.

Consumption of decaffeinated coffee did not lower the risk for depression.

“In this large prospective cohort of older women free of clinical depression or severe depressive symptoms at baseline, risk of depression decreased in a dose-dependent manner with increasing consumption of caffeinated coffee,” write the authors.

They note that this observational study “cannot prove that caffeine or caffeinated coffee reduces the risk of depression but only suggests the possibility of such a protective effect.”

The authors call for further investigations to confirm their results and to determine whether usual caffeinated coffee consumption could contribute to prevention or treatment of depression.

Source: JAMA and Archives Journals