By: National Institute of Mental Health
Depression can strike anyone, but people with diabetes, a serious disorder that afflicts an estimated 16 million Americans, (1) may be at greater risk. In addition, individuals with depression may be at greater risk for developing diabetes. Treatment for depression helps people manage symptoms of both diseases, thus improving the quality of their lives.
Several studies suggest that diabetes doubles the risk of depression compared to those without the disorder (2). The chances of becoming depressed increase as diabetes complications worsen. Research shows that depression leads to poorer physical and mental functioning, so a person is less likely to follow a required diet or medication plan. Treating depression with psychotherapy, medication, or a combination of these treatments can improve a patient's well-being and ability to manage diabetes.
Causes underlying the association between depression and diabetes are unclear. Depression may develop because of stress but also may result from the metabolic effects of diabetes on the brain. Studies suggest that people with diabetes who have a history of depression are more likely to develop diabetic complications than those without depression. People who suffer from both diabetes and depression tend to have higher health care costs in primary care (3).
Despite the enormous advances in brain research in the past 20 years, depression often goes undiagnosed and untreated. People with diabetes, their families and friends, and even their physicians may not distinguish the symptoms of depression. However, skilled health professionals will recognize these symptoms and inquire about their duration and severity, diagnose the disorder, and suggest appropriate treatment.
Depression Facts
Depression is a serious medical condition that affects thoughts, feelings, and the ability to function in everyday life. Depression can occur at any age. NIMH-sponsored studies estimate that 6 percent of 9- to 17-year-olds in the U.S. and almost 10 percent of American adults, or about 19 million people age 18 and older, experience some form of depression every year (4,5). Although available therapies alleviate symptoms in over 80 percent of those treated, less than half of people with depression get the help they need (5,6).
Depression results from abnormal functioning of the brain. The causes of depression are currently a matter of intense research. An interaction between genetic predisposition and life history appear to determine a person's level of risk. Episodes of depression may then be triggered by stress, difficult life events, side effects of medications, or other environmental factors. Whatever its origins, depression can limit the energy needed to keep focused on treatment for other disorders, such as diabetes.
Diabetes Facts
Diabetes is a disorder that impairs the way the body uses digested food for growth and energy. Most of the food we eat is broken down into glucose, a form of sugar that provides the main source of fuel for the body. After digestion, glucose passes into the bloodstream. Insulin, a hormone produced by the pancreas, helps glucose get into cells and converts glucose to energy. Without insulin, glucose builds up in the blood, and the body loses its main source of fuel.
In type 1 diabetes, the immune system destroys the insulin-producing beta cells of the pancreas. This form of diabetes usually strikes children and young adults, who require daily or more frequent insulin injections or using an insulin pump for the rest of their lives. Insulin treatment, however, is not a cure, nor can it reliably prevent the long-term complications of the disease. Although scientists do not know what causes the immune system to attack the cells, they believe that both genetic factors and environmental factors are involved.
Type 2 diabetes is often part of a metabolic syndrome that includes obesity, high blood pressure, and high levels of blood lipids. People with type 2 diabetes first develop insulin resistance, a disorder in which muscle, fat, and liver cells do not use insulin properly. At first, the pancreas produces more insulin, but gradually its capacity to secrete insulin falters, and the timing of insulin secretion becomes abnormal. After diabetes develops, insulin production continues to decline.
References
1 Diabetes statistics. NIH Pub. No. 99-3892. Bethesda, MD: National Institute of Diabetes and Digestive and Kidney Diseases, March 1999.
2 Anderson RJ, Lustman PJ, Clouse RE, et al. Prevalence of depression in adults with diabetes: a systematic review. Diabetes, 2000; 49(Suppl 1): A64.
3 Ciechanowski PS, Katon WJ, Russo JE. Depression and diabetes: impact of depressive symptoms on adherence, function, and costs. Archives of Internal Medicine, 2000; 160(21): 3278-85.
4 Regier DA, Narrow WE, Rae DS, et al. The de facto mental and addictive disorders service system. Epidemiologic Catchment Area prospective 1-year prevalence rates of disorders and services. Archives of General Psychiatry, 1993; 50(2): 85-94.
5 Shaffer D, Fisher P, Dulcan MK, et al. The NIMH Diagnostic Interview Schedule for Children Version 2.3 (DISC-2.3): description, acceptability, prevalence rates, and performance in the MECA Study. Methods for the Epidemiology of Child and Adolescent Mental Disorders Study. Journal of the American Academy of Child and Adolescent Psychiatry, 1996; 35(7): 865-77.
6 National Advisory Mental Health Council. Health care reform for Americans with severe mental illnesses. American Journal of Psychiatry, 1993; 150(10): 1447-65.
