Article Archive
Spring 2011

Bidirectional Diabetes-Depression Link

By Jaimie Lazare
Aging Well
Vol. 4 No. 2 P. 20

Research shows a bidirectional link between depression and diabetes requiring early screening and treatment to minimize the health complications of these comorbidities in older patients.

Receiving a medical diagnosis such as diabetes can be overwhelming for patients who experience a gamut of emotions, which can lead to depressive symptoms. While some patients eventually find a way to cope with their disease, others may experience prolonged sadness that can develop into major depression. And studies have shown that depression can lead to diabetes just as diabetes can contribute to depression. This relationship originated as early as the 17th century when English physician T. Willis noted that diabetes appeared in patients with sadness, prolonged sorrow, or significant life stresses.1 Many centuries later, the association between diabetes and depression is still being studied.

With the burgeoning elder population who are no strangers to chronic illnesses, the links between diabetes and depression hold even greater challenges for physicians regarding care management for this patient population. The Centers for Disease Control and Prevention estimates that more than 48 million Americans will have diabetes by 2050, with older adults being at greatest risk as the number of diabetics will triple among those aged 65 to 74, with an increase of five times its present level in those aged 75 and older.2 And the data on elder mental health issues fare no better, as 8% to 20% of older adults are diagnosed with major depression and age-associated increases in depressive symptoms.2 While studies have not fully identified the factors involved in the link between diabetes and depression, the evidence so far indicates a strong association that is important for clinicians to acknowledge, especially as they treat a growing population of older patients.

Research Linking Depression and Diabetes
The findings of a prospective study examining the bidirectional association between diabetes and depression concluded that compared with the reference group, women who were identified at baseline with depression demonstrated an elevated risk of developing type 2 diabetes, with an even higher risk for incident diabetes among antidepressant users.3 In the parallel analysis, the study’s findings suggested that the incidence of clinical depression among those who were defined as having diabetes at baseline was greater than those in the reference group, and the risk of depression was higher in patients with greater severity in their diabetes.3

Another study showed that lifestyle factors contribute to an association between depression and incident type 2 diabetes.4 Although impaired fasting glucose and untreated type 2 diabetes were not associated with incident depression, treated type 2 diabetes was found to be associated with depressive symptoms.4

Researchers in another study examined the different rates of depression among patients with either type 1 or type 2 diabetes and showed that type 1 diabetes was more likely to be linked to depression.5

“The thing about diabetes and depression is it’s a vicious cycle because diabetes is a chronic illness, and so people who have diabetes tend to have more issues with depression just because they’re dealing with something all the time—it’s unrelenting,” says Stephen R. Hammes, MD, PhD, the Louis S. Wolk Distinguished Professor of Medicine and chief of endocrinology at the University of Rochester Medical Center in New York. “On the other hand, if you have depression, then you tend to be less able to take care of yourself. And you’re not exercising and eating as well as you can. You may not be taking your medications as regularly which, of course, can make diabetes worse. So there’s always a constant struggle to try and prevent both of them before they happen because once you get one, the other is more likely to occur.”

Gender Differences
“Diabetes is an equal opportunity disease: Men and women have roughly the same incidence of diabetes,” say Enrico Cagliero, MD, an associate professor of medicine at Harvard Medical School and physician in the Diabetes Unit and Transplant Center at Boston’s Massachusetts General Hospital. “Depression, instead, is much more prevalent in women than in men.” However, since men don’t usually visit their physicians with complaints of depression, “We don’t really know whether they suffer from depression or whether it’s diagnosed less frequently in men, which helps to account for the gender difference. But on average, clinicians see more depression in women than in men,” Cagliero says.

“Historically, it’s been thought that women are more prone to suffering from depressive disorders than men are. Part of the problem is that we may not be diagnosing depression in men adequately. Men are not necessarily going to walk in the doctor’s office sobbing and saying, ‘Something’s just not right, and I don’t know exactly what it is.’ And so it’s a more difficult diagnosis to make in men for that reason,” says Maria Llorente, MD, associate chief of staff for mental health at the VA Medical Center in Washington, D.C. “Secondly, irritability is one of the ways men with depression present. It’s not one of the hallmark symptoms of depression, so it’s not going to get recognized that way either. Women in general have a tendency to be more likely to see their primary care provider when there is a medical problem, whereas men have a tendency to wait until there’s an acute crisis.”

Llorente says that during premenopausal and menopausal phases, some women may experience issues such as anxiety and sleep disturbances that can lead to depressive disorders. During andropause (male menopause), testosterone levels begin to decline when men are in their 40s, and they may experience depressive symptoms between the ages of 50 and 70 due to low testosterone levels, which can improve once a patient is treated with testosterone.

A study examining mortality risks in women between the ages of 54 and 79 with diabetes and depression indicated that comorbid depression and diabetes are associated with a significantly higher risk in women for all-cause and cardiovascular mortality rates.6

A longitudinal study of Mexican American seniors that examined the separate and combined effects of depression showed synergism between diabetes and depression leading to greater health complications, disability, and mortality. Because of these associations, screening guidelines have been recommended to identify elder patients with this comorbidity.2 However, screening for depression in older patients is still not performed often enough. A study reviewed 389 videotapes of older patient visits with their physicians, and the recordings showed that the physicians screen for depression in only 14% of visits during which formal measures were used only three times.2

Early recognition and intervention is the critically important component of managing depression in elder patients. Llorente says because of the vital nature of recognizing depression, multiple governmental bodies have recommended screening. The process isn’t extensive because the forms can be self-administered, and the patient’s score determines whether physicians should probe further. Screening tools include forms such as the Geriatric Depression Scale and the Patient Health Questionnaire-9.2

Cagliero says screening and treatment for diabetes are not universally done, and routine checks for diabetes should begin annually at the age of 45 in patients who don’t have risk factors such as obesity or a family history of diabetes. Earlier screening is recommended in those patients with diabetes risk factors.

“Diabetes is a difficult illness to take care of, and it’s difficult for primary providers because they often don’t have the time with every individual patient to address all those issues [by asking questions such as] ‘Did you see your eye doctor this year? Have you seen a podiatrist to make sure your feet are OK? Are you doing a filament test to make sure that you don’t have new neuropathy?’” Hammes explains. When it comes to screening either disease in elder patients, questioning them about how they’re feeling physically and mentally by asking if they are feeling more lethargic than usual and if they are having more trouble involving themselves in activities they previously found enjoyable will reveal clinically helpful information, Hammes adds.

Complexities in Management
Diabetes and depression as single conditions are complex diseases but when combined, their synergism further complicates the treatment of older patients. Many studies have shown that treating diabetes in patients who also suffer from depression doesn’t necessarily improve the depression, and clinicians should target depression specifically.2 Some other studies show that treating depression can improve diabetes. Cagliero and colleagues are currently conducting a study to determine the effects of cognitive behavioral therapy as a stand-alone treatment for depression in improving diabetes control and adherence to medications. Significant amounts of data show that treating depression results in dramatically improved diabetes, he says.

“We can certainly understand how psychological mechanisms contribute to health behavioral changes in diabetes patients who begin to see the illness as being intrusive, which can lead to the development of depression,” says Sherita H. Golden, MD, MHS, FAHA, an associate professor of medicine and epidemiology at the Johns Hopkins University School of Medicine, director of inpatient diabetes management service, and chairperson of the glucose management committee at the Johns Hopkins Hospital. “And once patients develop depression, it leads to elevated cortisol levels and patients become less likely to engage in good health behaviors, and that can worsen glucose control in the setting of having both diabetes and depression together. We actually need to do more research to understand if there are biological mechanisms active there.”

The first-line drug for diabetes is metformin because it seems to improve on resistance and has few side effects. But as patients get older, their creatinine clearance, kidney function, or liver function declines, and metformin use in these elder patients becomes less appealing, Hammes says.

“The best medication for treating diabetes is really insulin, and many people are resistant to starting it. But once patients get used to taking it, insulin is really one of the easiest drugs to take and has the lowest side effect profiles and you don’t have to worry as much about renal function, liver function, and other things that can become an issue as you get older. So we are big fans of using insulin especially when control gets more difficult with time, which is usually what happens with type 2 diabetes,” says Hammes.
Golden notes that atypical antipsychotics, often used in elders for sundowning and anxieties, can cause weight gain that can lead to the development of type 2 diabetes. If discontinuing these drugs isn’t an option for certain patients, then physicians should monitor their blood sugar regularly and encourage them to exercise.

And while pharmacotherapy helps treat depressed patients, physicians should consider recommending psychotherapy because it helps patients identify the issues that may be contributing to their depression, especially since older patients face various challenges such as becoming widowed or being unable to participate in certain activities. Psychotherapy and medication should be encouraged because they work well together, Golden says.

Patients should also consult a dietitian for further education on the importance of healthful eating habits. Dietitians are also specialized resources to help your elder patients with physical activity programs that can assist with weight loss. “It’s also a good idea for a spouse or caregiver who may be preparing the food to go to the dietitian visit with the patient because it’s really a group effort in terms of the behavioral management of diabetes,” Golden says.

With respect to diabetes and depression, it’s important for family members to become involved, particularly by accompanying older patients to the physician’s office because older patients may not process information as quickly, and in a very busy primary care practice, a lot of information is given to the patient, Llorente says.

In depression, associative symptoms are both physical and cognitive, yet few older adults use mental health services because of the stigma associated with depression, the minimization of the illness, and poor access to care. In those who recognize that they have a problem, only one-half receive treatment, with only 3% receiving care from specialty psychiatric services.2 For older patients, a serious aspect of depression involves thoughts of suicide. Statistics show elders have the highest rate of suicide among all age groups, and individuals aged 85 or older are twice as likely to commit suicide compared with the national rate.2

Llorente says on average, studies have found that 45% of individuals who commit suicide had contact with their primary care providers in the month prior to their suicide, and more than 70% had had contact with providers within the previous year.

The possibility of suicide is an important reason for physicians to recognize and treat depression, particularly in elder patients with diabetes. For suspected cases, physicians should inquire about whether a patient has thought about suicide and whether he or she has considered a plan of action. If so, the patient should be admitted for treatment because this is considered a psychiatric emergency, Golden says.

Research studies have shown a bidirectional relationship between depression and diabetes, and although the root cause for this connection is complex and requires further study, the data support the connection through which depression adversely affects diabetes and vice versa. This connection necessitates efforts toward better screening and treatment among this challenging and increasing population.

— Jaimie Lazare is a freelance writer based in Brooklyn, N.Y.


Medical Risks Accompanying Diabetes and Depression
Elder patients commonly deal with medical, physical, and social problems that can interfere with diabetes management, including depression. The negative bidirectional relationship between these two diseases, if untreated, can lead to serious complications. Research has shown the following:

• There is a significant increase among patients with depression and diabetes for complications such as amputation, vision loss, end-stage renal failure, myocardial infarctions, and strokes when compared with those diabetic patients without depression.

• Assessing patient self-care is important to ensure they are eating healthfully, taking diabetes medications, and staying active.

• Depression in patients with type 2 diabetes is associated with a significantly higher risk of developing microvascular (eg, end-stage renal disease, low vision, blindness) and macrovascular (eg, heart attack, stroke, congestive heart failure) complications than in patients with diabetes alone.

• Treating these patients encompasses a complex trade-off because research shows that treating depression improves diabetes. However, a side effect of antidepressants may be weight gain, which can undercut the progress achieved in improving diabetes while treating depression.

Older adults, as the fastest growing population segment, increase the incidence of chronic illness. The bidirectional link between diabetes and depression further complicates disease management. Greater collaboration among geriatricians, psychiatrists, and primary care physicians can increase the effectiveness of patient care.

— Source: Psychiatric News


1. Lloyd CE, Hermanns N, Nouwen A, Pouwer F, Underwood L, Winkley K. The epidemiology of depression and diabetes. In: Katon W, Maj M, Sartorius N, eds. Depression and Diabetes. Chichester, U.K.: John Wiley & Sons, Ltd; 2010.

2. Trief P. Depression in elderly diabetes patients. Diabetes Spectrum. 2007;20(2):71-75.

3. Pan A, Lucas M, Sun Q, et al. Bidirectional association between depression and type 2 diabetes mellitus in women. Arch Intern Med. 2010;170(21):1884-1891.

4. Golden S, Lazo M, Carnethon M, et al. Examining a bidirectional association between depressive symptoms and diabetes. JAMA. 2008;299(23):2751-2759.

5. Gendelman N, Snell-Bergeon JK, McFann K, et al. Prevalence and correlates of depression in persons with and without type 1 diabetes. Diabetes Care. 2009;32(4):575-579.

6. Pan A, Lucas M, Sun Q, et al. Increased mortality risk in women with depression and diabetes mellitus. Arch Gen Psychiatry. 2011;68(1):42-50.


Provider Prospective
• Screen patients for diabetes beginning at the age of 45. Start earlier for patients with risk factors such as family history or obesity.

• Screen elder patients for depression, as it’s often misdiagnosed or undiagnosed and, left untreated, can result in complications such as poor eating habits and lack of exercise.

• Many older patients take multiple medications. Recognize that certain medications (eg, atypical antipsychotics) may cause weight gain, a risk factor for developing diabetes.

• Consider psychotherapy in combination with pharmacotherapy, a combination shown to work well in treating depression.

• Admit a patient for evaluation and treatment by a psychiatric specialist if he or she shows signs of suicidal thoughts with a plan.