New Link Between Depression and Diabetes

For the first time, scientists at John Hopkins have found that diabetes contributes to depression. This has confirmed long-held assumptions about these two diseases being connected to each other that affect million of Americans. The research results, published in the Journal of the American Medical Association, provides added proof that diabetes plays a role in depression and vice versa. Previous studies conducted only looked at one aspect of this possible link.

An epidemiologist at the University of Michigan, Briana Mezuk and an expert on diabetes and depression, said that for many years research have already assumed the diabetes led to depression. She also added that what makes this study so great is the fact that the new research proves the evidence that these two diseases are linked.

Both diseases affect a significant number of people. Approximately 21 million American suffer from diabetes (7 percent of the population). According to the federal Centers for Disease Control and Prevention, the percentage of people with diabetes is even higher in Baltimore: One in 10 adults have the disease.

Approximately 30 million adults have had at lease one occurrence with serious depression in their lifetime (16 percent of the population). A diabetes expert at the Johns Hopkins School of medicine and the study's lead author, Dr. Sherita Hill Golden said, "We were able to show that there's a bidirectional association."

Golden stated that she hopes that this study will lead to an increased understanding among both the physicians and patients that the two diseases are closely connected. She also emphasized that the physicians who treat patients for diabetes show watch their patients closely for signs of depression.

This study looked a group that was ethnically diverse. There were approximately 6,814 men and women that participated that were between the ages of 45 and 84 spread across the United States. Over three years, the subjected visited a clinic 3 times for them to be examined for any symptoms of depression and type 2 diabetes. Type 2 diabetes is a chronic disease in which our bodies cannot properly removed sugar from our blood. The disease has a genetic component but usually occurs only in overweight people or those who have a diet that is high in sugars. It differs from type 1 diabetes, which is less common and is an autoimmune disorder in which our bodies with attack its own pancreas. The pancreas is the organ that makes insulin, the hormone that controls our blood sugar.

The participants with higher levels of depression were almost 50 percent more likely to develop diabetes than those participants who were not depressed to begin with. The subjects that were most depressed were most likely to develop diabetes. Compared with the rest of the population, people who are depressed tend to smoke more, exercise less, overeat, and be overweight. All of these factors tend to increase the risk of becoming diabetic. Golden's study found that the activities listed above contributed to he higher rates of diabetes for the participants with depression.

According to Golden, there are also other factors too. Golden, an endocrinologist, suspects that depression could cause physiological changes that could predispose people to diabetes. Depression raises the levels of hormones that cause stress such as cortisol as well as other molecules that can lead to inflammation. These chemicals can in turn contribute to diabetes. Depression has been found to play a role in several chronic physical conditions in addition to diabetes. For many years, scientists have known that depression is associated with higher rates of osteoporosis, heart disease, stroke, and possibly dementia. Inflammatory molecules and stress hormones play a role in all of the diseases previously listed.

Interestingly, the link found between diabetes and depression seems to be closely related to socioeconomic status. A new study that was conducted by the University of Michigan's Mezuk, which was published in the American Journal of Public Health, found that people that suffer from depression whose level of educational achievement was limited to high school or less had a 200 percent increased risk of developing diabetes.

This study also showed that people with depression with at least some college education had not increased risk. Mezuk suspects that the difference has something to do with the fact that in the subjects with less education and income, the depression tends to last longer- probably due to the fact that this group had less access to treatment. The longer that the depression persists, the more chance it has to do more harm.

Most researchers found that for patients that are diabetic who have become depressed, anxiety and worry play a central role. This disease is considered chronic, and these patients must think constantly about their diet as well as the possibility of complications, which could include peripheral nerve problems, heart disease and blindness.

A professor at the Johns Hopkins Bloomberg School of Public Health and an epidemiologist, William Eaton, said, "Either you have them or you're worried about getting them." Eaton has studied depression and diabetes for years but did not work on this particular study.

Golden found that the patients with diabetes who were getting treatment were more likely to be depressed that the patients that were not receiving treatment. She suspects that the diabetes treatment, which involves injections and regular monitoring, could cause psychological stress on patients, which could in turn cause an increasing risk of depression.

The awareness of the link between these two illnesses can make a significant difference: A study conducted last year by the University of Pennsylvania researchers found that diabetic patients with depression who received mental health care were half as likely to dies after two years compared with the depressed diabetic patients who did to receive any extra care. The study's lead author Dr. Hillary Bogner, a family medicine specialist at the University of Pennsylvania, said, "Treating depression is not only important for mental health, it's important for physical illness as well."