A new study claims that depression may result from diabetes, but it may also be a risk factor for it.
"Although it has been hypothesized that the diabetes-depression relation is bidirectional, few studies have addressed this hypothesis in a prospective setting," the authors wrote.
An Pan of the Harvard School of Public Health, Boston, and colleagues assessed the relationship between the two diseases among 65,381 women who were age 50 to 75 in 1996.
Participants were classified as having depression if they reported symptoms of depression, using antidepressant medication or being given a diagnosis of depression by a physician.
During the 10-year follow-up, 2,844 women were diagnosed with type 2 diabetes and 7,415 developed depression.
Results showed that women with depression were about 17 percent more likely to develop diabetes after controlling for other risk factors, such as physical activity and body mass index (BMI). And those who were taking antidepressants had a 25 percent higher risk of developing diabetes than those who did not have depression.
Women with diabetes were 29 percent more likely to develop depression. Women who took insulin for diabetes had a further increased risk-53 percent higher than women without diabetes.
The results indicate that depression may have an effect on risk for diabetes beyond weight and inactivity. In addition, the findings reinforce the idea that diabetes is related to stress, the authors noted.
"Future studies are needed to confirm our findings in different populations and to investigate the potential mechanisms underlying this association," the authors concluded.
The report appears in the November 22 issue of Archives of Internal Medicine.