Dr. Santamarina is an assistant professor of pharmacy practice at the Lloyd L. Gregory School of Pharmacy, Palm Beach Atlantic University, West Palm Beach, Florida.
How common is the prevalence of diabetes and depression? A meta-analysis conducted by Anderson et al1 reported the prevalence of depression in patients with diabetes to be between 18% and 31%, resulting in approximately a twofold higher depression prevalence, when compared with nondiabetic patients. A recent national US survey, conducted in 2006, assessed key behavioral risk factors among adults suffering with diabetes.2 This survey detected an 8.3% age-adjusted prevalence rate of major depression in patients afflicted with diabetes. This prevalence rate of depression occurrence exhibited regional disparities from as low as 2% in Connecticut to as high as 28.8% in Alaska. Furthermore, this survey estimated a 25-fold difference in major depression amidst diverse racial and ethnic groups.2
The association between diabetes and depression is not limited to the adult population. Depression is more commonly present in adolescent patients with diabetes, when compared with nondiabetic adolescents. A recent largepopulation study conducted by a Kaiser Permanente research team of patients with type 1 diabetes, aged 10 to 21 years, found that 14% presented with mildly depressed mood, whereas 8.3% presented with moderately to severely depressed mood.3
Individuals stricken with depression may experience one or more of the following behaviors: loss of interest or motivation in performing daily activities, change in sleep patterns, excessive sleeping or insomnia producing daily fatigue, change in appetite, and lack of energy. Generally, achieving adequate glycemic control requires patients with diabetes to adopt multiple lifestyle changes, including following a new dietary plan, increasing physical activity, self-monitoring and recording blood glucose levels, and adhering to pharmacotherapy. The intricacy of these lifestyle changes can be overwhelming for individuals with diabetes and more so for individuals afflicted with concomitant diabetes and depression. What then happens when a patient has the 2 D's: diabetes and depression? What are the clinical implications and outcomes of this combination?
Multiple studies have examined the medication adherence patterns of patients afflicted with diabetes and depression.4,5 Kalsekar et al4 followed the adherence habits of depressed and nondepressed individuals with newly diagnosed type 2 diabetes to oral antiglycemic medications over a 12-month period. The depressed group discontinued their pharmacotherapy regimen 1.51 times more frequently than the nondepressed group. Additionally, the depressed group changed their oral hypoglycemic agents 1.72 times more frequently than nondepressed patients.
Another study followed the adherence to diet, exercise, and self-monitoring of blood glucose in patients afflicted with major depression or some depression symptoms and type 2 diabetes.5 Patients suffering with major depression and diabetes had statistically significant less adherence to diet, exercise, and self-monitoring of blood glucose than their less depressed counterparts. Furthermore, the major depressed group exhibited a 2.31 times greater chance of missing one or more medication doses during any given week.5
The existing literature is inconclusive with respect to the association among diabetes, depression, and hemoglobin A1C (HbA1C) values, likely due to the heterogeneous study designs. A German study reported no association between diabetes, depression, and HbA1C values in a community sample of patients aged 18 to 79 years.6
In contrast, Katon et al reported an association between high HbA1C values in patients younger than 65 years old with diabetes and depression.7 No association was found, however, between high HbA1C values in patients older than 65 years with diabetes and depression.7
Unfortunately, depression is not readily recognized as a common complication of diabetes. Current American Diabetes Association (ADA) Standards of Medical Care guidelines recommend that health care providers perform psychosocial assessment and care as part of a comprehensive diabetic treatment plan, however. According to the ADA, assessing for psychosocial issues includes screening for depression, anxiety, eating disorders, and assessing cognition when adherence is poor.8
Depression makes it increasingly difficult to manage a chronic disease such as diabetes. For this reason, pharmacists should counsel patients with diabetes or their caregivers to be watchful and to report any signs of depression to their health care provider. Although patients with diabetes may develop depression at any given time, the following situations describe times when a patient with diabetes may be at a higher risk for experiencing poor psychologic well-being that may lead to depression:
In patients who are newly diagnosed with diabetes:
In patients who have had diabetes for several years:
In patients suffering with long-term complications of diabetes:
In patients during their adolescent years:
Pharmacists are in an ideal position to offer patients with diabetes counseling and to warn them to be watchful and report any symptoms of depression in order to achieve optimal control of diabetes so patients can enjoy a good quality of life.