Depression and diabetes is the topic of several recent studies which we want to examine here so that you as an informed medical consumer can best take care of yourself and others you love. The impact of depression on the person with diabetes is significant.
An article in the Archives of Internal Medicine by Ciechanowski, MD et all suggests that depressive symptom severity is associated with poorer diet and medication adherence, functional impairment, and higher health care costs in primary care diabetic patients.
First let’s examine just what depression is. It is a treatable illness involving neurotransmitters, which are brain chemicals. The symptoms include:
- prolonged sadness or unexplained crying spells
- significant changes in sleeping or eating patterns
- irritability, anger, worry, agitation, anxiety
- pessimism, indifference
- loss of energy, lethargy
- feelings of guilt, worthlessness
- inability to concentrate, indecisiveness
- inability to experience pleasure in former activities, social withdrawal
- unexplained aches and pains
- recurring thoughts of death or suicide.
This is not an illness that you can diagnose in yourself. A trained physician or psychologist can do this. A complete physical exam should be part of this process as well as a complete family history and recent personal history.
People with major depressive disorder have had at least one major depressive episode with 5 or more symptoms for at least a two week period of time. For some people the disorder is recurrent.
Dysthymia is a chronic, moderate type of depression. People with mild dysthymia may not know they have it as they can continue functioning, but they may have eating and sleeping symptoms and feel fatigued.
Who gets depression? The short answer is anyone, but mostly frequently it first occurs between the ages of 25 and 44. In the US more than 20 million people experience depression every day.
Children can also become depressed. When my husband and I first moved to Washington, DC, we were friendly with the physician who first researched this illness in children and wrote about its etiology and symptoms.
Before that, depression, although seen in children, was not diagnosed. Also of note is the fact that of the 32 million Americans over 65 years of age, nearly 5 million experience serious symptoms of depression and a million suffer from a major depressive disorder.
Elderly people with untreated depression are likely to have poorer outcomes from treatment for coexisting medical conditions such as hypertension, diabetes or heart disease. Although women are twice as likely as men to experience depression, men suffer because they are less likely than women to seek help.
For men, it is often masked by alcohol or drug abuse which may seem more socially accepted than seeking psychiatric help.
Now we need to get more specific and discuss the prevalence of depression in adult people with diabetes. For these facts we look to research by Ryan Anderson et al which was published in Diabetes Care 24:1069-1078.2001.
This research estimates the odds and prevalence of clinically relevant depression in adults with type 1 and type 2 diabetes. Why do such a study? As we have stated many times before on this site, emotional distress is associated with hyperglycemia and an increased risk for diabetic complications.
Relief of depression is associated with improved glycemic control and a better quality of life so this information is very important. The research used MEDLINE and PsycINFO databases and published references, to identify studies that reported on the prevalence of depression in the diabetic population.
Prevalence was calculated as an aggregate mean weighted by the combined number of subjects in the included studies. The authors used statistical means to asses the rate and likelihood of depression as a function of diabetes, sex, subject source, depression assessment methods, and study source.
The conclusions of the research are important for all of to understand. The authors estimated the odds and prevalence of diabetes and depression from 39 studies having a combined total of 20,218 subjects, so we can not fault the authors for a low “n”.
The principal conclusion of the review is that diabetes doubles the odds of depression. The odds ratio (OR) of depression is more consistent across studies than the prevalence, which varied by sex, study design, subject source, and methods of assessment.
The overall OR estimate generalizes across community and clinical settings despite differences in prevalence rates between these settings. Both clinicians and epidemiologists can expect people with diabetes to be twice as likely to be depressed than otherwise similar people in similar settings such as those selected by similar procedures, the same sex, and assessed with comparable depression assessment methods. In contrast, the prevalence estimate must be adjusted for moderators such as sex.
So now lets look at these numbers. Estimates from all the studies indicate that major depression and elevated depression symptoms were present, respectively, in 11% and 31% of people with diabetes.
The odds of depression were significantly higher in women than in men with diabetes (OR1.8), a pattern that mirrors the prevalence of female depression in the general population. This means that close to one in every three women with diabetes was found to have symptoms of depression.
The symptoms of depression found in this survey are at a level that impairs functioning and quality of life, adherence to medical treatment, glycemic control and increases the risk of diabetes complications.
The prevalence of depression varied as a function of the method used to identify depression and the study design. Furthermore, in both controlled and uncontrolled studies, the depression rates were approximately two to three times higher in studies that used self-report measures versus diagnostic interviews.
The authors speculated that the two approaches identify somewhat different but overlapping samples of depressed people. It is thought that self-report measures may identify a broader spectrum of depression disorders such as dysthymia , or minor or subclinical depression, or it may reflect comorbid psychiatric illness such as anxiety or substance abuse disorders or general distress.
The prevalence of depression in type 1 and type 2 diabetes could not be established. The ORs from controlled studies was nearly identical between types, and aggregate estimates of prevalence using controlled and uncontrolled studies, segregated by depression assessment method, also yielded equivalent depression rates.
Many of the studies, including those with the highest “n” did not report the fraction of depressed people by type of depression. This exemplified a more general failure of many studies to fully characterize the depressed and nondepressed samples. This information is needed to assess the effects of other factors like age, socioeconomic status, and severity of diabetes on the prevalence of depression. In particular, failure to report race or ethnicity is common in psychosocial literature on diabetes.
What seems to come through loud and clear is that depression is associated with diabetes, thus replicating other research. How the complex interactions of physical, psychological, and genetic factors affect this remains uncertain.
Depression may occur secondary to the hardships of advancing diabetes or to diabetes-related abnormalities in neurochemical or neurotransmitter function. On the other hand, evidence from prospective studies in the US and Japan indicates that depression doubles the risk of incident type 2 diabetes independent of its association with other risk factors.
In people with preexisting diabetes, depression is an independent risk factor for coronary heart disease, and appears to accelerate the presentation of coronary heart disease. The authors conclude that additional studies are needed to identify the behavioral and physiological mechanisms that account for these findings.
The Third National Health and Nutrition Education Examination Survey found that 49% of insulin-treated diabetics and 56% of those on oral agents had HbA1c values <8.0% and very few people sustained HbA1c levels <7.0%, the goal set by the American Diabetes Association.
Depression may oppose efforts to achieve normoglycemia via behavioral and physiological pathways, and, as shown in this review, is clinically relevant in nearly one of every three patients with diabetes.
Successful treatment of depression is associated with improvements in glycemic control. The sad truth is that two of every three cases of depression are left untreated by primary care physicians. The authors suggest better recognition and better treatment of depression to improve better medical outcome in a substantial portion of people with diabetes.
Let’s look back at what we have tried to share with you. First, we gave you definitions of symptoms of depression and the names of some depression illnesses. We also stressed the fact that a professional should make the diagnosis of depression, not you alone. For sure, depression can be treated in many ways, from talking therapies to drug therapy and combinations of both.
We then looked at the study of the odds and prevalence of depression in diabetes. The final result to take to heart is that we are at risk for depression and that to protect ourselves and our loved ones, we need to be aware and have a healthy, honest relationship with our health care team. If you have any questions, feel free to contact us. We’ll do our best to answer you with the best information we can glean from professionals. Thanks for reading and keeping ahead of the curve.