Coffee can reduce risk of depression

The study, involving more than 50,000 women, found that drinking four or more cups of caffeinated coffee cut the risk of clinical depression by 20 per cent compared with drinking one or fewer cups per week.

Mental health campaigners said different people would vary in their reaction to food and drink and should consider what effect different substances had on them.

The research involved 50,739 women who participated in the Nurses’ Health Study, a major US investigation exploring links between health and lifestyle.

None of the women, who had an average age of 63, had depression at the start of the ten-year study, which began in 1996.

A “dose response” was also seen, with two to three cups of coffee per day reducing the relative risk of depression by 15 per cent, rising to a 20 per cent drop with those having four or more.

The researchers in the US said they could not be sure of a causal link between coffee consumption and avoiding depression, but they had taken account of factors such as marital status and smoking, which could also influence their results.

The researchers, writing in the journal Archives of Internal Medicine, found no similar link with decaff coffee or other sources of caffeine, including soft drinks, tea and chocolate.

The scientists, led by Dr Michel Lucas from the Harvard School of Public Health in Boston, said: “Our results support a possible protective effect of caffeine, mainly from coffee consumption, on risk of depression.

“Further investigations are needed to confirm this finding and to determine whether usual caffeinated coffee consumption may contribute to prevention or treatment of depression.”

A previous study from Finland found a reduced risk of suicide with progressively higher levels of coffee consumption.

This association continued until coffee consumption reached eight to ten or more cups a day, at which point suicide risk increased.

The scientists pointed out that caffeine had “well-known psychostimulant effects” including “increased sensations of well-being and energy”.

These were known to be dose-dependent but “biphasic” – meaning that higher doses could reverse the “pleasant and stimulating” effect of lower doses.

Ilena Day, chief executive of Scottish charity Action on Depression, said: “Linking coffee with depression or lack of it depends on individual reactions, both psychologically and physiologically.

“It is generally helpful for people who suffer from depression to always take a close look at their lifestyle, food, and drinking habits. Certain foods and beverages can affect people’s moods, and coffee is definitely one of them.”