A study of 32,257 people between 20 and 50 years of age with type 2 diabetes indicates that patients with newly diagnosed diabetes were more likely to have a history of depression (4.9%) than those without diabetes (3.8%). This finding is considered important because the typical onset of depression occurs between the ages of 20 and 30. Thus, the people who are at the highest risk of developing depression are also the ones with the highest risk of developing type 2 diabetes.
It has long been known that diabetes and depression often co-exist and depression is associated with the worst outcomes in diabetics. It has not been clear, however, if depressed people are predisposed to developing diabetes. Several mechanisms may be at work including weight fluctuations and sedentary lifestyles which are both common in depressed individuals and which are both increase the risk of developing diabetes. Another theory is that many of the medications
used to treat depression cause weight gain and sedation which, again, are risk factors for the development of diabetes.