Study reveals bidirectional relationship between diabetes complications and mental illness

Heart attacks, strokes, nerve damage.

These are just a few of the complications that put millions of Americans with diabetes at greater risk.

A University of Michigan-led study found that people with chronic diabetes complications are more likely to suffer from mental illness, and vice versa.

This means the relationship is bidirectional, and having a mental illness also increases the risk of developing chronic complications of diabetes.

“We wanted to find out whether chronic diabetes complications lead to mental illness or whether mental illness leads to diabetes complications, and we found that both relationships were true.”

Brian Callahan, MD, MS, senior author, and Eva L. Feldman, MD, professor of neurology in the U-M School of Medicine.

“The findings highlight the need for clinicians to proactively screen for mental illness in their diabetic patients, in addition to screening for chronic complications, which is the recommended standard of care for patients with diabetes.”

A research team led by the Department of Biostatistics at the University of Michigan Medicine and the University of Michigan School of Public Health examined insurance claims data from more than 500,000 people with type 1 or type 2 diabetes and 350,000 people without diabetes.

The results were announced Diabetes Care People with chronic diabetes complications were found to be up to three times more likely to develop mental disorders such as anxiety and depression, and this effect increased as adults grew older.

People with mental illness were up to 2.5 times more likely to experience lasting complications from diabetes.

In adults under 60, type 1 diabetes is associated with more chronic complications. People with type 2 diabetes, which is more common, are more likely to experience mental health problems.

According to the researchers, a possible reason for this two-way relationship may be that diabetic complications and psychiatric disorders directly influence the development of other complications.

“For example, a stroke can have detrimental effects on the brain that can directly lead to depression,” Callahan said.

“Furthermore, the comorbidity of psychiatric disorders and diabetes may affect self-management of the disease, such as poor glycemic control and non-compliance with medication, which may increase the risk of diabetes complications.”

And the relationship may not be so direct: Diabetes complications and mental illness share common risk factors, and obesity, problems with blood sugar control, and social determinants of health can all increase the chance of developing both complications.

“It's probably a combination of direct and indirect effects and shared risk factors that are driving the associations we're seeing,” said lead author Shinya Watanabe, a biostatistician at the Harvard T.H. Chan School of Public Health and a former graduate research assistant at the University of Michigan.

“By offering interventions to treat these common risk factors, diabetes care providers may be able to prevent the risk of multiple complications simultaneously.”

According to the CDC, over any 18-month period, up to 50% of people with diabetes may experience distress related to their condition.

Although some national diabetes centers screen patients for depression and distress, no universal screening process for mental health in diabetes care exists.

The researchers note that screening for and managing psychiatric disorders will require additional resources, as many clinicians who manage diabetes do not have specific training to appropriately identify and treat them.

This is consistent with a statement from the U.S. Preventive Services Task Force, which says that patients who test positive for a mental illness should receive “an appropriate diagnosis and treatment with evidence-based care or referral to a facility that can provide the necessary care.”

“Primary care providers and endocrinologists are already overwhelmed, so we need to put in place systems of care that allow them to provide mental health care when needed,” said co-author Eva Feldman, MD, James W. Albers Distinguished Professor, director of the ALS Center of Excellence at the University of Michigan.

“These systems should include mental health screening, readily accessible insurance coverage for mental health services, and education programs for both doctors and patients. Action is needed, and our new study provides further evidence that this action is needed now.”