It has long been known that there is a connection between Type 2 diabetes and depression, and recent research suggests that the relationship between these two conditions works in both directions — in other words, depression may be both a risk factor for developing Type 2, as well as a consequence of having it. People with diabetes are three to four times as likely to have major depression as people in the general population.
To evaluate the relationship between depression and Type 2 diabetes, researchers from the Harvard School of Public Health recruited 65,381 women who were between the ages of 50 and 75 in 1996. The participants completed questionnaires regarding their medical history and health practices at the beginning of the study period, along with follow-up questionnaires every two years for the next ten years. Women who reported symptoms of depression, diagnosis of a depression by a physician, or the use of antidepressant medicines were classified as having depression.
Over the course of the 10-year follow-up period, 2,844 women developed Type 2 diabetes and 7,415 were diagnosed with depression. After controlling for risk factors such as physical activity and body-mass index, women with depression were roughly 17% more likely to develop diabetes; those who were taking antidepressants had a 25% higher chance of developing diabetes. And after controlling for risk factors for other mood disorders, women with diabetes were 29% more likely to develop depression; women taking insulin had a 53% higher risk of developing depression than women without diabetes.
According to the study authors, the data supports the idea that diabetes is related to stress, noting that “A diagnosis of diabetes may lead to symptoms of depression for the following reasons: depression may result from the biochemical changes directly caused by diabetes or its treatment, or from the stresses and strains associated with living with diabetes and its often debilitating consequences.”
The authors suggest lifestyle interventions such as weight management and regular physical activity as a means of lowering the risk of both depression and diabetes.
To learn more about the research, read the article “Depression May Be Both Consequence of and Risk Factor for Diabetes” or see the study’s abstract in the Archives of Internal Medicine. And for information on treating depression, read nurse David Spero’s four part–series on the topic.