Depression doesn’t seem to affect blood glucose levels, while stress does. But there are simple ways to do something about both.

In a study published in the April 2007 Psychosomatic Medicine, Richard Surwit, PhD, chief of Duke’s Division of Medical Psychology, and colleagues found that cognitive behavioral therapy -- basically teaching people to see life as a glass that’s half full, rather than half empty -- improved depression in a group of patients with diabetes.

But treating depression did not have any effect on blood sugar control. Surwit was surprised at the results because previous research, though mixed, had suggested that depression and glucose control were linked. His own study, with Duke colleague Mark Feinglos, MD, had shown a small connection in patients with type 1 diabetes.

“I was just stunned,” Surwit says. “Cognitive behavioral therapy’s effect on depression was so significant, and yet there was no effect on A1C [a marker of glucose levels over time].”

Even though treating depression doesn’t seem to have any effect on diabetes, it’s well known, from research by Surwit and others, that stress can raise blood sugar.

Stress causes the body to make more hormones such as epinephrine, norepinephrine, and cortisol, which can lead to disruptions in the body’s normally tight control of blood sugar. However, reducing stress will produce a significant improvement in hemoglobin A1C over one year.

Cognitive behavioral therapy, as well as progressive muscle relaxation, can also produce reliable decreases in these hormones. For example, in one of their earliest studies of stress and diabetes control, Surwit and Feinglos had 12 diabetes patients stay in a dormitory setting. Half of them learned and practiced progressive muscle relaxation.

That group showed decreased blood sugar after only nine days, and blood samples revealed that their cortisol levels were measurably lower than the control group’s.

“When the patient is having trouble controlling their glucose, physicians might suggest that they monitor their blood glucose in situations where they feel they’re under stress, and in situations where they feel they’re not,” Surwit says. “And if there’s a pattern there, a physician can recommend that they do something about it behaviorally.”

For instance, self-help books such as Surwit’s The Mind-Body Diabetes Revolution can help people learn simple techniques to manage stress on their own.

“The reason I did this book was, for most people, insurance is not going to pay for behavioral intervention unless there’s a psychiatric diagnosis,” he says.

Muscle relaxation sounds easy enough, but can people really practice cognitive-behavioral therapy on their own? Yes, Surwit says.

“We created a structured set of exercises that you can do to look at a situation, analyze it, decide whether the way you are responding is appropriate or not, and then change how you are responding if necessary.

“A lot of stress that we put on ourselves has to do with how we appraise what’s going on around us,” he says.

For example, if your work supervisor snaps at you, you might assume that he’s unhappy with you. Or, you could assume that he’s just having a bad day.

“People have to be able to figure out which is which. If your boss is having a bad day, that’s too bad for your boss, but it’s not something that should make you upset.”