People with diabetes are twice as likely to suffer from depression as those who do not have the disease, according to a new study published in the ADA journal Diabetes Care. Analyzing 25 years of data, researchers documented - for the first time - increased rates of depression in people with diabetes. Women with diabetes are even more likely than men to become depressed, which is also the case in the general population.

How the two diseases interact is not understood, nor is it clear whether one causes the other. However, physical inactivity and overeating, which are common symptoms in depression, are also linked to the development of type 2 diabetes. And previous studies have shown that treating depression can improve blood glucose control.

The lead researcher from Washington University School of Medicine urges people who have both conditions to get treatment for both. "Treat both, and both will improve," he said.