Drinking two or more cups of coffee a day may prevent depression in women.
That's according to researchers from the Harvard School of Public Health, in Boston, who say caffeine in coffee could alter the brain's chemistry.
So women needn't bother reaching for their favorite brew of decaf, which scientists say will have no effect.
Caffeine is the world's most frequently used central nervous system stimulant - and 80 percent of it comes from coffee.
The study's author, Michel Lucas, and his colleagues, used questionnaires to measure the caffeine consumption of 50,739 U.S. nurses during a 10-year period, from 1996 to 2006.
Their findings were published Monday in the Archives of Internal Medicine.
Women who drank two to three cups of coffee a day were 15 percent less likely of developing depression than women who drank one cup of coffee or less per week, reported The Wall Street Journal.
Consuming four or more cups a day even further reduced the risk of depression, by 20 percent.
The BBC said that just over 2,600 of the women developed depression over the 10-year period, and most tended to be “non- or low-coffee drinkers”.
Researchers say their work suggests caffeine has a "protective effect" in staving off depression, which is a condition that affects twice as many women than men.
But they stopped short of concluding that caffeinated coffee reduces the risk of depression – so your doctor won't be prescribing you a cuppa just yet.
The experts are now recommending more work to better understand the link.