Women who drink coffee are less depressed.

A new study showed that the women who drank two to three cups of coffee a day were 15 percent less likely to develop depression over a 10-year period than those who drank one cup of coffee or less per week.

It is important to note that the new study only shows an association between coffee consumption and depression risk, and it cannot proved that drinking coffee increases risk of depression in women. At these studies have taken a part more than 50,000 women in the United States. The new study is just the latest to suggest coffee consumption has health benefits. Earlier work has found an association between drinking coffee and a reduced risk of breast cancer, prostate cancer and stroke.

As Dr. Seth Berkowitz, wrote in an editor's note accompanying the new study: "According to these results reassure coffee drinkers that there seem to exist no glaringly deleterious health consequences to coffee consumption. Because the study only shows a correlation between coffee and the risk of depression, it's too soon for doctors to recommend coffee consumption to patients.”

Caffeine and depression

About 80 percent of people in The United States consume caffeine drink and most of is a coffee. But caffeine's effect on depression is not well known yet.

The researchers analyzed surveys of 50,739 U.S. women (average age 63). From 1980 through 2004, participants filled out questionnaires about their caffeine consumption, including how often they drank coffee, tea and soda. Participants were followed from 1996 to 2006 to see whether they were diagnosed with depression. None of the participants had depression at the study's start. Women were considered depressed if they had been given a diagnosis of clinical depression by their physician and they started taking antidepressants.

Over the 10-year period, 2,607 new cases of depression were reported. Women who drank four or more cups of coffee per day were 20 percent less likely to develop depression than those who drank one or fewer cups of coffee per week.

No link was found between consumption of decaffeinated coffee and depression.

Some people who consume caffeine experience sleep disturbances, insomnia or anxiety. It's possible that women with a history of depression, or women who are predisposed to depression, know about these side effects and reduce their caffeine consumption.

Women should aim for a healthy balance in diet, stress reduction and exercise and be mindful of depression symptoms that require help from health professionals.