Diabetes and Depression: Knowing the Signs, Improving Outcomes

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.

An individual with diabetes complains to a health care provider of fatigue, exhaustion, and the inability to control her/ his blood glucose levels despite multiple efforts. Are these symptoms of uncontrolled diabetes, symptoms of depression, or symptoms of both? Which one of the 2 "D's" should the health care provider assess and treat? Both is the correct answer.

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:

• The patient may find it difficult after being told they now have a "chronic or irreversible" disease.
• The patient may feel overwhelmed with the self-care responsibilities needed to control diabetes.

In patients who have had diabetes for several years:

• At any time, the patient may feel discouraged because, despite multiple efforts following a restrictive regimen of diet, exercise, and selfmonitoring of blood glucose, their diabetes remains uncontrolled.
• Given the progressive nature of diabetes, the initial medication regimen, diet, and exercise regimen, which allowed the patient to attain adequate glycemic control, is "no longer working to control the diabetes." The patient will be told additional medication(s) are needed. This may make the patient feel their diabetes is getting worse.
• Oral antiglycemic medications in a patient with type 2 diabetes no longer control the diabetes, and the patient needs to start an insulin regimen. Many patients are resistant to the initiation of insulin injections, despite their efficacy. The patient may feel fearful and overwhelmed about injections and syringes, and may be anxious about measuring the correct units of insulin to inject.
• Men may suffer from erectile dysfunction, leading to self-esteem issues and/or relationship problems.
• At any time during the disease process, the patient may feel that the diabetes is controlling his or her life, rather than that he or she is controlling the diabetes.
• The patient is initiated on a new medication or on an insulin regimen and experiences hypoglycemic episode( s), making the patient scared and anxious.
• The patient is still unable to control her/his high blood glucose and continuously wakes up at night to urinate, preventing him/her from having a good night's sleep and feeling tired throughout the day.
• Elderly patients who have been selfmanaging their diabetes for years may feel "burnt out" and tired and express that they "do not want to do all this anymore."

In patients suffering with long-term complications of diabetes:

• The patient may face microvascular complications of diabetes, such as decreased eyesight or blindness, kidney problems or end-stage renal disease on dialysis, or neuropathic pain in the lower or upper extremities or both.
• The patient faces macrovascular complications of diabetes, such as stroke, myocardial infarction, peripheral vascular disease, and, in some cases, amputations.

In patients during their adolescent years:

• Patients with type 1 diabetes commonly exhibit a very strong desire "to be like other kids" and may express feeling that they "no longer want to have diabetes," become rebellious, and in some instances, refuse to follow their usual insulin regimen.

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.

References

• Anderson RJ, Freedland KE, Clouse RE, Lustman PJ. The prevalence of comorbid depression in adults with diabetes: a meta-analysis. Diabetes Care. 2001;24(6):1069-1078.
• Li C, Ford ES, Strine TW, Mokdad AH. Prevalence of depression among US adults with diabetes: findings from the 2006 behavioral risk factor surveillance system. Diabetes Care. 2008;31(1):105-107.
• Lawrence JM, Standiford DA, Loots B, et al. Prevalence and correlates of depressed mood among youth with diabetes: the SEARCH for diabetes in Youth Study. Pediatrics. 2006;117(4):1348-1358.
• Kalsekar ID, Madhavan SS, Amonkar MM, et al. Depression in patients with type 2 diabetes: impact on adherence to oral hypoglycemic agents. Ann Pharmacother. 2006;40(4):605-611.
• Gonzalez JS, Safren SA, Cagliero E, et al. Depression, Self-care, and medication adherence in type 2 diabetes: relationships across the full range of symptom severity. Diabetes Care. 2007;30(9):2222-2227.
• Kruse J, Schwmitz N, Thefeld W; German National Health Interview and Examination Survey. On the association between diabetes and mental disorders in a community sample: results from the German National Health Interview and Examination Survey. Diabetes Care. 2003;26(6):1841-1846.
• Katon W, von Korff M, Ciechanowski P, et al. Behavioral and clinical factors associated with depression among individuals with diabetes. Diabetes Care. 2004;27(4):914-920.
• Executive Summary: Standards of Medical care in Diabetes-2008. Diabetes Care. 2008;31:S5-S54.