Coffee may prevent depression, scientists say

Women who drink two or more cups of coffee a day are less likely to get depressed, research suggests.
It is not clear why it might have this effect, but the authors believe caffeine in coffee may alter the brain's chemistry. Decaffeinated coffee did not have the same effect.
The findings, published in Archives of Internal Medicine,  come from a study of more than 50,000 US female nurses. The experts are now recommending more work to better understand the link. And they say it is certainly too soon to start recommending that women should drink more coffee to boost mood.

Source  - BBC