According to a study in the Archives of Internal Medicine published in October 2011, the more caffeinated coffee women drink, the less likely they are to develop depression. No links were seen between other sources of caffeine and decaffeinated coffee.

The study was based on 50,000 women in the Nurse's Health study. Those drinking 2-3 cups per day had a 15% lower risk for depression and 4 or more cups a day lowered risk by 20%, compared to drinking 1 cup or less a week.

COMMENT: There have been numerous studies on coffee, all of which have shown benefits for many conditions and no particular dleterious health effects. It appears that something in the coffee besides caffeine may serve as a natural anti-depressant. However, I wouldn't recommend drinking lots of coffee simply to lower your chance of depression.