Coffee is good for you, as its mood-boosting effect could well be lasting far longer than we realise, says a new Harvard University study.

The study, which compared the coffee intake and risk of depression amongst nearly 51,000 women over 10 years, found that those who drink four or more cups a day are a fifth less likely to become depressed.

And those who drink between two or three cups a day cut their risk by 15 per cent, found the study, published in the Journal of American Medicine Association. Though the study did not look at men, other studies have already found that it has a similar effect.