Does coffee reduce the risk of depression?

Women who drink caffeinated coffee could be reducing the likelihood of suffering from depression by doing so on a regular basis. This is the finding of new research published in the Archives of Internal Medicine, which suggested increasing consumption of the drink is associated with decreased depression risk.

The study was carried out by investigators at the Harvard School of Public Health in Boston, US - which was established in 1922 when it split from the Massachusetts Institute of Technology - and found females who have two to three cups a day are 15 per cent less likely to experience the condition than those who only drink one cup or less a week.

However, no such connection was established between depression risk and decaffeinated varieties of the product.

The authors wrote: "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."

Professor Peter Rogers, Fellow of the British Psychological Society, commented: "It is not obvious what can explain this association. Due to tolerance, the psychostimulant effects of caffeine are reduced or abolished with frequent consumption coffee (so that withdrawal causes fatigue), and we found a positive cross-sectional association between habitual level caffeine consumption and sub-clinical levels depressed mood, anxiety and stress.

"It is possible that the protective effect observed in this older group of women in the Harvard study is related to the reduced risk of cognitive decline associated with tea and coffee consumption, which in turn may be explained by the neuroprotective action of various constituents of these drinks, including polyphenols and, indirectly, caffeine."