Eating dark chocolate could boost mood and relieve symptoms of depression, scientists say, according to 7News.

Adults who tucked into the treat had 70 per cent lower odds of reporting depressive symptoms than those who ate no chocolate at all, the research showed.

The team studied data from 13,626 adults in the US and also found the 25 per cent who ate the most chocolate of any kind were less likely to report depressive symptoms than those who did not eat it.

But the survey was only a "snapshot" and further research is needed to confirm a link, experts have cautioned.

Lead author Dr Sarah Jackson, from University College London's Institute of Epidemiology and 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."

The team, who worked with the University of Calgary and Alberta Health Services Canada, found no significant link between not eating dark chocolate and depressive symptoms.

"Further research is required to clarify the direction of causation," Dr Jackson said.

"It could be the case that depression causes people to lose their interest in eating chocolate, or there could be other factors that make people both less likely to eat dark chocolate and to be depressed."

Data was gathered from the US National Health and Nutrition Examination Survey.

Adults' chocolate consumption was checked against their scores on the Patient Health Questionnaire, which looked at depressive symptoms.