drinking coffee
One in 5 US women experience depression during their lifetime.

Drinking caffeinated coffee reduces depression risk, research finds.

The more caffeine women in the study drank, the lower their chances of becoming depressed.

Drinking two to three cups of coffee a day was linked to a 15% reduction in depression risk.

Those drinking four or more cups per day had a 20% reduced risk.

Other studies in men have also suggested that caffeine intake is linked to lower depression.

The conclusions come from a study that followed 50,739 US nurses.

They were tracked for 10 years and none were depressed at the start of the study.

Over the study's duration, their intake of caffeinated drinks was tracked.

This included caffeinated soft drinks as well as non-herbal tea and coffee.

The study's authors explain the results:
"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."
However, due to the nature of the study it:
"...cannot prove that caffeine or caffeinated coffee reduces the risk of depression but only suggests the possibility of such a protective effect."
Decaffeinated coffee was not linked to any reduction in risk.

The study was published in the journal Archives of Internal Medicine (Lucas et al., 2011).