A new study suggests that for people who have poorly controlled diabetes, treating underlying depression may actually help reduce blood sugar and blood pressure levels to boot. The research was published in the December 2009 issue of Diabetes Care.

Diabetics suffer from depression at rates twice that of the general population. What’s more, minorities suffer from depression even more frequently, and minorities with diabetes are much more likely to have poorly controlled blood sugar and diabetes−related health complications. The authors of the current study wanted to determine if treating depression alone might have a secondary effect on blood sugar and blood pressure in minorities suffering from uncontrolled diabetes.

The authors found a significant correlation between depression and blood sugar level for all participants.

The team, led by Mayer B. Davidson at Charles Drew University, followed 89 diabetes patients who were seeking treatment for depression at a diabetes clinic. All were minorities and considered “low−income.” They put half of the participants on the anti−depressant medication sertraline (commercially known as Zoloft), and half on Placebo. All participants were asked to attend monthly diabetes education sessions over the course of the study. After six−months, the researchers evaluated the participants for blood sugar, blood pressure, and depression.

The team found that the blood sugar level of participants who were prescribed sertraline had fallen significantly more than that of the placebo group. Hemoglobin A1C levels, a common marker of blood sugar level, had fallen by 2% (from 10% to 8%) in participants taking sertraline, versus just 0.9% in those taking placebo (from 9.7% to 8.8%). Generally, hemoglobin A1C levels below 7% are considered desirable in people with diabetes. Blood pressure also fell significantly more in the sertraline group than in the placebo group.

Interestingly, both groups reported about the same degree of improvement in depression and other psychological measures. Still, the authors found a significant Correlational study between depression and blood sugar level for all participants. Treating depression alone or in conjunction with standard diabetes therapies may be a route clinicians will take in the future.