Can Depression Cause Diabetes?

A new study from the Feinberg School of Medicine at Northwestern University suggests that chronic depression may increase the risk of developing diabetes in older adults. The study appeared in the April 23, 2007 edition of The Archives of Internal Medicine. Other studies have linked depression and diabetes together, but this is the first study to research whether chronic depression, independent of other risk factors, such as obesity or physical inactivity, can increase the incidence of a diabetes diagnosis. The answer appears to be, "Yes, it can."

4,681 people, age 65 and older took part in the study and were tracked for 10 years. According to the summary of the research,

“We know that overweight and obesity are the primary risk factors for diabetes and most people with Type 2 diabetes are overweight or obese,” Mercedes Carnethon PhD, assistant professor of preventive medicine at Northwestern's Feinberg School of Medicine and lead author of the study explains, “But even after we adjusted for [statistically accounted for] body mass index [measure of height versus weight], we still saw a residual association between depression and diabetes.”

The culprit appears to cortisol, a hormone produced in response to stress. When someone is depressed, cortisol levels rise. If depression is chronic, cortisol levels may stay consistently high. High levels of cortisol have been shown to impair insulin sensitivity and contribute to fat distribution in the waistline area. Excess belly fat is a known risk factor for diabetes.

More on the topic of depression and diabetes:

• Diabetes and Depression - A Vicious Cycle
• Loss is Part of Living

Photo by Ramzi Hashisho