Lauren Brown then studied the medical history of 2,400 people who were diagnosed with depression and were taking antidepressants to determine whether there was a clear correlation between that disease and type 2 diabetes.

She divided the group into four categories: those who took antidepressants that were considered older therapies, patients who were using newer treatments, those using a combination of both an old and new treatments and people who were switching medications.

The study, published in Diabetes Research & Clinical Practice, found the risk of diabetes almost doubled for the patients who were using two types of therapies at the same time, tricyclic antidepressants and selective serotonin reuptake inhibitors.

Brown said the results emphasize the need for regular screening for type 2 diabetes in people with depression -- particularly those taking more than one antidepressant.