Beatrice Golomb, Natalie Rose and Sabrina Koperski from the University of California questioned participants about their chocolate consumption and measured their mood using the Center for Epidemiologic Studies Depression Scale (CES-D).

They found that both men and women who had high depression scores ate on average 11.8 medium portions of chocolate per month, whereas those with lower depression scores ate 8.4 and those with no depression ate only 5.4 portions per month. A portion was considered to be 1 ounce, which is slightly less than an a standard chocolate bar.

"Our study confirms long-held suspicions that eating chocolate is something that people do when they are feeling down," said Dr. Golomb.

It is not clear, however, whether, the chocolate consumption leads directly to an increase in depression or whether depression increases chocolate cravings. There may of course be a more complicated relationship between the two variables.

"Because it was a cross sectional study, meaning a slice in time, it did not tell us whether the chocolate decreased or intensified the depression." said Dr Golomb.

Previous studies in rats have suggested that chocolate may be beneficial to mood, but in this study it did not appear to benefit the participants, as they still had high depression scores even though they consumed a lot of chocolate.

It could be argued that people just eat more when they are depressed and that this includes more chocolate, but this was ruled out by the study: "The findings did not appear to be explained by a general increase in caffeine, fat, carbohydrate or energy intake, suggesting that our findings are specific to chocolate," said Golomb.

There was also no difference in the consumption of other antioxidant-rich foods, such as fish, coffee, fruits and vegetables between those with depression and those without. 

Source: Adapted from materials provided by EurekAlert (Press Release)