Caffeine is the world’s most widely used central nervous system stimulant.

For many women their day doesn’t really kick into action until they have had their morning cup of coffee. Only then can they launch into action and attempt the multi tasking that is required to get through the day.

50,000 middle-aged women took part in the trial over a 10 year period which formed the study, Coffee, Caffeine, and Risk of Depression Among Women. It found that women who drank 2 to 3 cups of caffeinated coffee a day were 15% less likely to develop depression compared with women who consumed 1 cup or less per day. Women who drank 4 or more cups of coffee a day had a 20% lower risk.

Led by senior author Dr. Alberto Ascherio, a professor of epidemiology and nutrition at Harvard School of Public Health, the study is one of the first to investigate the long-term effects of caffeine on mood disorders such as depression.

The results showed that there was an association between coffee consumption and mood, rather than a direct correlation proving that coffee consumption prevented depression. Previous research (Suicide: A prospective study of coffee drinking and suicide in women) has also found that people who drink coffee are less inclined to suicide.

Ascherio says “Our results suggest that caffeine may have a beneficial effect on the cellular level, and may protect neurons lost to neurodegenerative disease. We are establishing a certain degree of reasonable evidence that caffeine has a long-term effect on the risk of depression, but we cannot attribute this to any pathology.”

Like other compounds that affect the body’s metabolism, caffeine may reduce the risk of depression only up to certain doses. At high doses, caffeine can increase anxiety, which can actually contribute to depression.

“The amount of coffee you drink is very much determined by how you feel, and there is no guarantee in the long run that drinking coffee will be beneficial. We adjust to the level of caffeine that is optimal for us, and we cannot give a prescription for people to drink or not drink caffeine,” said Dr. Ascherio.

The study concluded that “In this large longitudinal study, we found that depression risk decreases with increasing caffeinated coffee consumption.”

Writer Helen Splarn. Editor Dr Ramesh Manocha.
Source: Time. Archives of Internal Medicine