A new study finds that diabetes and mental health are linked. People with chronic diabetes complications are at a three-times greater risk of having a mental health condition.

People who have one of several chronic complications from diabetes — such as nerve damage, stroke, and heart attack — are more likely to have a mental health disorder and vice versa, finds new research from the University of Michigan.

In fact, people with chronic diabetes complications had up to a three-times greater risk of having a mental health condition, such as anxiety or depression. This effect increased as adults got older. And those diabetes and a mental health disorder were up to 2.5 times more likely to experience sustained diabetes complications. These results were published in July 2024 in Diabetes Care.

Brian C. Callaghan, M.D.

“We wanted to see if chronic diabetes complications led to mental health disorders or if mental health disorders led to those diabetes complications – but we found that both relationships are true,” Brian C. Callaghan, M.D., professor of Neurology and a neuromuscular specialist at the University of Michigan and one of the authors, said in a news release.

Because of this association, researchers suggested that “clinicians and healthcare systems should revise standards of care practices to include MHD [mental health disorder] screening and treatment …active and universal screening for MHDs is needed for all patients with diabetes at the point of care,” they wrote.

Researchers — led by Maya Watanabe, M.S., a biostatistician at the Harvard T.H. Chan School of Public Health — wanted to understand whether mental health disorders lead to chronic diabetes complications or whether chronic diabetes complications lead to mental health disorders in people with type 1 or type 2 diabetes.

The research team examined insurance claims data from 2001 to 2018 from more than 500,000 people with type 1 or type 2 diabetes and 350,000 people without diabetes. Researchers identified patients using the Optum’s Clinformatics Data Mart Database with validated ICD-9 and ICD-10 codes. In addition, researchers identified a random sample of 20% of the study population without type 1 or 2 diabetes ICD-9 or ICD-10 codes.

The researchers found a consistent bidirectional association between chronic diabetes complications and mental health disorders in patients with both type 1 and type 2 diabetes.

In adults younger than 60 years old, having type 1 diabetes was more associated with chronic complications. People with type 2 diabetes were more likely to experience mental health difficulties.

Researchers also tried to understand whether chronic diabetes complications led to mental health disorders or whether it was the other way. They found, however, that both were true.

Researchers suggested that having a diabetes complication or mental health condition has direct effects on developing the other complication. “For instance, a stroke causes detrimental effects on the brain, which may directly lead to depression,” Callaghan said. “And having a mental health condition and diabetes may affect a person’s self-management of their condition — like poor glycemic control or not taking medications — which, in turn, may increase their risk of diabetes complications.”

But the relationship may be less direct. “Most likely, a combination of direct and indirect effects and shared risk factors drive the association we are seeing,” said Watanabe.