New research on treatments for depression presents an intriguing finding: a healthy diet may help depressed patients.

It is part of the nascent field of nutritional psychiatry which uses changes in diet to help treat mood disorders. Researchers are always looking for new treatments for depression and other mental-health disorders because many people don’t respond to antidepressant medications and psychological therapies.

The study, published Monday in the journal BMC Medicine, found that a third of patients assigned to a group that followed a modified Mediterranean diet met the criteria for remission in 12 weeks, compared with just 8% in a control group. Remission as assessed by a patient’s score on a diagnostic questionnaire used by psychiatrists to determine the severity of depression.

There is a large body of evidence, both observational studies and animal studies, that links diet to the risk of developing depression and the prevalence of depression, said Felice Jacka, a professor of psychiatric epidemiology and nutritional psychiatry at Deakin University in Australia and senior researcher on the study. Dr. Jacka is also president of the International Society for Nutritional Psychiatry Research.

Psychiatrists cautioned that the study provides no evidence that diet changes could replace traditional treatments for depression; but it could be beneficial as an add-on treatment.