Diabetes and Depression

Over 30 million people in the United States live with diabetes and studies have shown that individuals who have diabetes are 2-3 times more likely to have depression than the general public. While the reason for this common comorbidity is unknown, many scientists believe that it may be connected to both biology and behavior. In both people with depression and people with diabetes, it is common for the HPA (hypothalamic-pituitary-adrenal) axis to be activated which is known to control responses to stress and also helps to regulate body functions such as digestion and mood. Additionally, things like poor sleep, poor nutrition and lack of exercise are common to both a diagnosis of depression and of diabetes.

Depression and diabetes seem to have a bidirectional connection, meaning that having depression seems to lead to an increased chance in developing diabetes and having diabetes seems to lead to an increased chance of developing depression. Additionally, it seems that when symptoms of diabetes are more severe, it is common for depression symptoms to increase—which often leads to less self-care—creating a vicious cycle.

Unlike some other comorbid conditions, diabetes and depression have an added complication in that the medications often used to treat depression, while still very effective, can have effects on glycemic control making it very important that your health care physicians can work in collaboration to provide the best treatment.

People with diabetes and even their physicians may misinterpret depression's warning signs, mistaking them for normal responses to a new diagnosis of diabetes or thinking common symptoms like lethargy and weight change are only due to diabetes. Feelings related to a new diagnosis will usually begin to go away within a few weeks. If these feelings last longer and are interfering with your ability to live your life, it may be time to seek help for depression.

Notes and Sources

Diabetes and depression occur together approximately twice as frequently as would be predicted by chance alone. Comorbid diabetes and depression are a major clinical challenge as the outcomes of both conditions are worsened by the other. Although the psychological burden of diabetes may contribute to depression, this explanation does not fully explain the relationship between these 2 conditions. Both conditions may be driven by shared underlying biological and behavioral mechanisms, such as hypothalamic-pituitary-adrenal axis activation, inflammation, sleep disturbance, inactive lifestyle, poor dietary habits, and environmental and cultural risk factors. Depression is frequently missed in people with diabetes despite effective screening tools being available. Both psychological interventions and antidepressants are effective in treating depressive symptoms in people with diabetes but have mixed effects on glycemic control. Clear care pathways involving a multidisciplinary team are needed to obtain optimal medical and psychiatric outcomes for people with comorbid diabetes and depression.

A meta-analysis of 9 cohort studies found that adults with depression had a 37 % increased risk of developing type 2 diabetes [18] after accounting for factors common to both disorders including sex, body mass index, and poverty.

In addition, there are a number of diabetes specific risk factors associated with depression. In people with type 2 diabetes, the rates of depression are higher amongst those using insulin compared with noninsulin medications or dietary and lifestyle interventions alone [1920]. 
A number of symptoms, such as lethargy, irritability, or weight change, are common to both conditions

As poor metabolic control, low rates of blood glucose self-monitoring, and diabetes complications all predict inadequate response to depression treatment, an equal emphasis on both diabetes and depression is needed.

Depression can strike anyone, but people who have diabetes appear to be at greater risk. In fact, studies suggest that people who have type 2 diabetes have a much as double the risk of depression as people who don’t. The rate of depression is thought to be at least three times higher in people with type 1 diabetes than in people without diabetes.

In a vicious cycle, people with depression may be at greater risk for developing diabetes. Thus, the strong diabetes depression link.

As diabetes complications get worse, it is common for depression to increase as well, which can lead to a lack of proper self-care.

The reason for the link between diabetes and depression is unclear. It may be due to the stress of having diabetes, by behaviors that contribute to both conditions or by shared underlying biological mechanisms.

Some symptoms of depression may reduce overall physical and mental health, not only increasing the risk for diabetes but making diabetes symptoms worse. For example, overeating may cause weight gain, a major risk factor for diabetes. Fatigue or feelings of worthlessness may cause people to ignore a special diet or medication plan needed to control their diabetes. Studies have shown that people who have both diabetes and depression have more severe diabetes symptoms than people who have diabetes alone.