"That's important not only because people with diabetes will feel better if we can control their depression. It's also key to helping manage blood sugar," says Patrick J. Lustman, Ph.D., principal investigator and professor of psychiatry. "As depression improves, glucose levels also tend to improve."
Although depression affects about 5 percent of the general population, the rate is about 25 percent for patients with diabetes. Lustman's team previously demonstrated that treatment with antidepressant drugs and psychotherapy is an effective way to treat depression in patients with diabetes, but often depression would quickly redevelop.
"As we better understand depression, it's clear that for many patients, it is a chronic and recurring disease," Lustman says. "That appears to be especially true for patients with diabetes compared to those otherwise free of medical illness"
Although they knew that short-term treatment with antidepressants was helpful with mood and with control of blood glucose, Lustman's team didn't know whether the drug could prevent the recurrence of depression in patients with diabetes. He also didn't know what would happen to glucose levels in the months following successful depression therapy.
So Lustman teamed up with investigators at the University of Arizona, Tucson, and at the University of Washington, Seattle. They studied a total of 152 patients with diabetes at the three sites. The sample included patients with type 2 diabetes and patients with juvenile, or type 1, diabetes. Study participants averaged just over 50 years of age, and all had recovered from an episode of depression following treatment with sertraline (Zoloft).