Women who drink four cups of coffee a day are a fifth less likely to become depressed than those who rarely drink coffee according to researchers in the US. As well as providing a lift in energy, it's also thought that coffee can provide a lift in well being when consumed regularly. A team at Harvard School of Public Health, led by Alberto Ascherio, found that women who regularly drink four or more cups of coffee a day have 20% lower risk of developing depression. The study looked at long term use of caffeinated coffee in a group of over 50,000 women with an average age of 63 with no current depression issues, measuring their coffee consumption since 1976 and then following their health and coffee drinking for a further 10 years. It's thought that caffeine might protect against neurotoxins in relevant brain receptors, although the exact reasons for the effects are not known. Other studies, by Ascherio's team and a small study in Finland, found that drinking coffee may protect against Parkinson's disease and even reduce the likelihood of committing suicide, although there have been few studies into the long term effects and Ascherio states that many more studies will be needed to show whether coffee can prevent depression. 
