Diabetes mellitus is a chronic violation of all types of metabolism in the body, especially carbohydrate metabolism. Moreover, with type 1 diabetes mellitus, the insulin necessary for breaking down sugar is simply not produced by pancreatic cells, and with type 2 diabetes it is produced, but the cells and tissues of the body do not perceive it.
Statistics show that diabetes is as widespread among the population as depression. But, despite numerous studies, the causes of both conditions leave a lot of blank spots. Recently, the attention of doctors and scientists has been increasingly attracted by the fact that both of these diseases are often found together in one patient. It turned out that people with depression have a higher risk of carbohydrate metabolism disorders, which is typical for diabetes. And, on the other hand, patients with diabetes often have a persistently low level of mood.
In the first scientific work devoted to this issue, the author noted a clear connection between depression and diabetes. In his opinion, “grief and prolonged sadness” ultimately disrupted the patient’s carbohydrate metabolism and caused diabetes. The article was released several centuries ago, and all this time it was believed that a diabetes patient is depressed because of his problems and anxiety.
In 1988, it was hypothesized that depression may be accompanied by lower tissue susceptibility to pancreatic hormone insulin, which is important in the development of diabetes. Another author published the data of his study, during which he gave antidepressants to diabetic patients with diabetic neuropathy. It turned out that such treatment reduced both depression and pain caused by neuropathy.
Almost 10 years later, another work came out. This time, the author observed 1715 patients with diabetes for 13 years and concluded that with type 2 diabetes, the risk of depression is higher than in healthy people. His data began to be double-checked, a lot of interesting work was done that made it possible to establish: yes, indeed diabetes is often accompanied by depression.
Insulin sensitivity and cortisol
It only remained to find out the sheer smallness – why. Eight years ago, the results of a large meta-analysis were described in the literature (when they take a few scientific papers and look for general things in them). It turned out that patients with depression are at risk for carbohydrate metabolism disorders. And this violation was associated with a number of important points:
- A depressed person is characterized by a sedentary lifestyle; such patients smoke a lot, and some directly “seize” their troubles with sweets.
- It is shown that adrenal hormone cortisol and pro-inflammatory cytokines (substances that contribute to inflammation) are released during depression. These events may decrease the sensitivity of cells and tissues to insulin. \
- Increasing cortisol levels contributes to obesity with the accumulation of major fatty deposits on the abdomen, and such obesity is already a risk factor for type 2 diabetes.
A diabetic patient, on the other hand, has many reasons to develop depression. Having been diagnosed with diabetes, patients have to start monitoring their blood glucose levels on their own, change their diet, drink medication or take insulin on time, increase physical activity, reduce weight, and at the same time regularly visit a doctor to monitor the progress of the disease. Some patients are seriously afraid of complications, including hypoglycemia. And all this taken together can easily end in depression. One of the authors working on this problem showed that depression is less common in patients with undiagnosed type 2 diabetes than in patients with a diagnosis.
Do diabetes complications make depression worse?
Even worse is the development of diabetes complications. Scientists have proven that damage to the eyes, kidneys, nervous system and large vessels in diabetes affects the formation of a depressive state. How exactly is this influence realized? Researchers suggest that slow inflammation and poor nutrition of the nerve tissue caused by cytokines reduce the flexibility and adaptability of the nervous system and can become a source of depression in the future. In addition, complications of diabetes are also associated with an increase in the level of the hormone cortisol, which, as we recall, can be released during depression.
Diabetes, Depression, and Stress in Diabetes Patients
Another theory has been developed that can combine depression with type 2 diabetes. The fact is that both of these conditions can be caused by stress. Various experts pointed out that the impaired carbohydrate metabolism is associated with mental injuries received when the patient was still a child (for example, with insufficient warmth in relations with parents). Stress can contribute to unhealthy behavior – smoking, alcohol abuse, unhealthy diets, and decreased activity in everyday life. In addition, under stress, the same cortisol is released, which causes obesity in the abdomen and tissue resistance to insulin. However, this theory does not explain why depression is equally common in patients with type 1 and type 2 diabetes.
The effect of depression on diabetes
With depression, a patient with diabetes is more difficult to achieve improvement and complications more often occur. The patient’s quality of life and, in general, desire to be treated are reduced. Interestingly, a combination of both diseases leads to an increase in healthcare costs for treatment.
Thus, depression is often associated with diabetes. However, today a lowered mood in a diabetic patient is considered a normal response to the diagnosis of a chronic serious illness, and signs of depression are not given any significance. Methods for detecting depression in patients with diabetes mellitus and new, additional studies are needed, because, despite the abundance of publications on the relationship between depression and diabetes, many aspects of the process are still unclear.
Meanwhile, it is estimated that in children born today, the risk of diabetes during life exceeds 35%. Therefore, it is so important to find out how this disease is associated with depression, and to develop methods for treating patients with both pathologies.