Scientists have found that eating dark chocolate appears to lower the risk of depression by four fold.
While 7.6 percent of the 13,000 people surveyed reported depressive symptoms, just 1.5 percent of the chocolate eaters did.
The study by University College London (UCL), the University of Calgary and Alberta Health Services Canada, also found that the people who consumed the most of any chocolate were also 57 percent less likely to report depressive symptoms.
Lead author Dr Sarah Jackson, of UCL's Institute of Epidemiology & Health Care, said: "This study provides some evidence that consumption of chocolate, particularly dark chocolate, may be associated with reduced odds of clinically relevant depressive symptoms.
"Should a causal relationship demonstrating a protective effect of chocolate consumption on depressive symptoms be established, the biological mechanism needs to be understood to determine the type and amount of chocolate consumption for optimal depression prevention and management."
The study is the first to examine the association with depression according to the type of chocolate consumed.
Chocolate contains a number of psychoactive ingredients which produce a feeling of euphoria similar to that of cannabinoid, found in cannabis.
It also contains phenylethylamine, a neuromodulator which is believed to be important for regulating people's moods.
Dark chocolate also has a higher concentration of flavonoids, antioxidant chemicals which lower inflammation and can prevent the onset of depression.
However British scientists urged caution about the findings, suggesting that the decision to eat dark chocolate could be linked to other health factors. For example people who choose dark chocolate may be more health conscious in general, which is known to protect against depression.
Depressed people are also more likely to crave more sugary fatty foods and so could be less likely to pick a dark alternative when choosing chocolate.