The occurrence of depression is two to three times higher in people with diabetes mellitus, most cases remain underdiagnosed.

Depression is a common and very serious medical illness, with a lifetime prevalence ranging from approximately 11% in low-income countries to 15% in high-income countries. The lifetime risk of having a mental health problem is around 50% and this leads to a drop in employment, productivity and wages. Depression and anxiety are the fourth cause, while diabetes is the 8th cause of disability-adjusted life years (DALYS) in developed countries.

As defined by the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-5), diabetes is a mood disorder that brings together several symptoms that alter an individual’s functionality. Depression disrupts emotions, cognition, and behavior.

Signs and symptoms

Due to the negative aspects in relation to the individual’s health and also to the health systems, the co-morbidity of diabetes and depression has provoked many studies in the last decade. There are three possibilities for the association of diabetes and depression: both diseases may have a common etiology; diabetes increases the prevalence or risk of future depression; and depression increases the prevalence or risk for future diabetes.

Recent studies have shown that there are no common genetic factors to explain the positive association between depression and type 1 or 2 diabetes. However, different environmental factors (epigenetic factors) may activate common pathways that promote DM2 and ultimately depression. An important factor is a low socioeconomic status that increases the chances of DM2, but also seems to be a cause of depression. The other common causes of T2DM and depression are poor sleep, lack of exercise and diet.

Chronic stress activates the hypothalamic-pituitary-adrenal axis (HPA axis) and the sympathetic nervous system (SNS), increasing cortisol production in the adrenal cortex and adrenaline and noradrenaline production in the adrenal medulla. Chronic hypercortisolemia and prolonged activation of the SNS promote insulin resistance, visceral obesity and lead to metabolic syndrome and T2DM. On the other hand, chronic stress has behavioral consequences: noradrenaline, cortisol and other hormones activate the fear system, determining anxiety, anorexia or hyperphagia; the same mediators cause tachyphylaxis of the reward system, which produces depression and cravings for food, other substances, or stress. Excess cortisol disrupts neurogenesis in the hippocampus, a region involved in depression as well as T2DM.

Furthermore, chronic stress induces immune dysfunction either directly or through the HPA axis or SNS by increasing the production of inflammatory cytokines. Elevated amounts of inflammatory cytokines interact with the normal functioning of pancreatic beta cells, induce insulin resistance, and thus promote the onset of T2DM. New studies suggest that inflammatory responses are also involved in the pathophysiology of depression. Pro-inflammatory cytokines have been found to interact with many of the pathophysiologic domains that characterize depression, including neurotransmitter metabolism, neuroendocrine function, synaptic plasticity, and behavior. 50% of patients treated with interferon Alfa developed depression and patients with depression had statistically higher blood levels of cytokines such as tumor necrosis factor and interleukin 6 than those without depression.

These correlations suggest that stress and inflammation promote depression and T2D, giving a viable common link between them.

Patients with DM1 need a different and more complicated treatment of their disease compared to DM2: they need frequent blood glucose monitoring, adjusting insulin doses, diet and physical activity. The age of onset for DM1 is much earlier than for DM2; the close chronological relationship between DM1 and the onset of depression is surprising, the diagnosis of DM1 and its treatment burden occurs at a time when the individual has an increased vulnerability to depression.

Children and adolescents with diabetes have a two to three times higher prevalence of depression than young people without diabetes. Poor glycemic control in pediatric DM1 is related to both depression and lower socioeconomic status, and the chances of depression in these patients increase as glycemic control worsens. There are not many studies on T1DM and depression, but an important review on the subject highlights a biological link: increased circulating cytokines associated with autoimmune diabetes, lack of insulin affecting neurogenesis and neurotransmitter metabolism, the effects of chronic hyperglycemia and the iatrogenic effects of hypoglycemia and hyperactivity in the HPA axis. Similar to T2DM, it appears that T1DM and depression have common pathophysiological pathways, contrary to what was traditionally thought that the burden of diabetes increases the prevalence of depression.

Risks

Many risks are considerable as the rampant increase of diabetes. Non-medication and lack of body care can develop obesity and many risks can arise ahead and that can cause blurred vision, blindness, cardiorespiratory problems and even death.

diagnosis

The incipient diagnosis of depression should speed up your way of treating it. Therefore, be aware of the references that are more naturally located in the early stages of the depressive process, such as:

• Losing the feeling of pleasure in doing things you used to enjoy;
• Increased sadness without apparent motivational action, mainly in the morning;
• Certain change in sleeping habits. Incipient awakening and difficulty going back to sleep;
• Certain essential changes in appetite, more or less in quantity;
• Experience difficulties in concentration;
• Having a feeling of tiredness and strength damage;
• Increased anxiety, nervousness or excessive guilt;
• Suicidal or self-harm thoughts.

The appearance of three or more of these symptoms, or only, or only one or two symptoms, however, associated with a feeling of fado due to two weeks or more, demonstrates the need for the patient or victim to adhere, whether in a depressive state and, due to this, he or she orders toseek contributions with expert and competent collaborators in assisting the person with diabetes.

Treatment

The best way to treat with antidepressants should be necessary and, to this end, a medical professional orders to be consulted. Antidepressants can be administered and a basic diet with moderate physical activity suggested.

When symptoms of depression appear, it is not advisable to wait a long time to seek professional assistance, and to find out more about the disease and seek multidisciplinary care services for those who already have diabetes.

Bibliographic references

DIAS, A.M. et al. Adherence to therapeutic regimen in chronic disease: literature review. Millennium, 40, p. 201-219, 2011

Hermanns, N; Caputo, S; Dzida, G. et al. Screening, evaluation and management of depression in people with diabetes in primary care. Primary Care Diabetes. 2013; 7: 1-10

Tapash, R; Lloyd Cathy, E. Epidemiology of depression and diabetes: A systematic review. Journal of Affective Disorders. 2012; 142S1:S8-S21.