A new study suggests that generalized anxiety disorder independently correlates with a steeply increased susceptibility to Type 2 diabetes, highlighting a potential and debilitating long-term effect of everyday worrying that's familiar to many.

Published March 30 in the Journal of Psychosomatic Research, the study showed that even after taking into account major risk factors, including prediabetes, people with symptoms of generalized anxiety disorder, or GAD, had a greater likelihood of developing Type 2 diabetes. For those with moderate to severe anxiety, the risk was more than double.

"We were surprised that although individuals with GAD were not more likely to be obese — which is the main risk factor for Type 2 diabetes — they still had a two-times higher risk of developing Type 2 diabetes," Seryan Atasoy, lead author of the study, told The Academic Times. 

Atasoy, a postdoctoral researcher affiliated with the Technical University of Munich, explained that generalized anxiety disorder is relatively common. Characterized by persistent and excessive worrying in daily life, it affects nearly 7 million U.S. adults, but fewer than half report receiving necessary treatment.

When left unaddressed, mental strain such as social anxiety, work-related stress, nervousness about school and other ubiquitous experiences can all manifest as generalized anxiety disorder. These days, researchers are even pondering politics as an anxiety-inducing topic.

"Yet," Atasoy said, "it had come to our attention that the association between GAD and future risk of Type 2 diabetes remained unclear."

"A previous study by our group showed that GAD amplifies the progression from prediabetes to Type 2 diabetes," she added. "Hence, it was of interest whether GAD would have such an effect even without the presence of prediabetes."

In people with Type 2 diabetes, the body is unable to efficiently respond to insulin and maintain proper blood sugar levels. It differs from its counterpart, Type 1 diabetes, in which the body can't make insulin at all. Without therapeutic intervention, which includes routine insulin injections, the condition creates dizziness and fatigue, and if left untreated for longer, it can lead to complications such as nerve and kidney damage.

Another important distinction is that Type 2 diabetes is preventable. According to the researcher, the anxiety that may induce it can be, too.

"Seeking mental health care when feeling high levels of daily anxiety and stress is a crucial preventive measure that could be taken by individuals," Atasoy said, "along with leading a healthy lifestyle, including engaging in physical activity — which itself is a preventive measure against GAD as well as Type 2 diabetes."

The team discovered the strong relationship between anxiety and Type 2 diabetes risk by collecting patient data from already in-place German cohorts, which inform studies relating to prediabetes. After sifting through recruitment criteria, the researchers chose 1,694 participants, almost evenly split in terms of men and women, with a mean age of 51.2 years.

Symptoms of anxiety were tested on a scale called the GAD-7 questionnaire, according to the paper. Study subjects with a score of GE 10, which typically indicates a confirmed case of generalized anxiety disorder and a higher level of generalized anxiety, such as panic disorder, were found to face a doubled risk of developing Type 2 diabetes.

Additionally, "There is evidence that each increasing score is associated with a higher risk of Type 2 diabetes as well, but this finding did not reach significance," Atasoy noted. "Further analyses with a larger sample size are needed to clarify the effect of mild symptoms of GAD on Type 2 diabetes risk."

Another potential limitation of the GAD-7 questionnaire is that it incorporates a subjective telling of anxiety experiences or a self-reported physician diagnosis by the test-taker rather than a formal, clinical diagnosis of the disorder. However, Atasoy conveyed that the GAD screener is highly sensitive and specific.

Aside from this study, which built on a previous work that sought to understand the broader relationship between diabetes and anxiety, it is already speculated that chronic stress and anxiety affect physical processes in the body.

"There could be such a strong correlation because stress is independently associated with biological dysregulations that increase insulin resistance — eventually leading to Type 2 diabetes," Atasoy explained.

She added that, as supported by the study, generalized anxiety disorder is also associated with additional mental health risk factors, including depression. Because depression is known to activate inflammation, that can also disrupt physiological processes.

"We hope that the scientific community considers the vast effect of psychological factors on the incidence of Type 2 diabetes, and that the general public is aware of the long-term consequences of constant daily worrying," Atasoy concluded, "which is the hallmark of GAD."

The study, "Generalized anxiety disorder symptoms and type 2 diabetes onset: Findings from the Prospective Cooperative Health Research in the Region of Augsburg F4 and FF4 studies," published March 30 in the Journal of Psychosomatic Research, was authored by Seryan Atasoy, University of Gießen and Marburg, German Research Center for Environmental Health, German Center for Diabetes Research and Technische Universität München; Hamimatunnisa Johar, Technische Universität München, German Research Center for Environmental Health and German Center for Diabetes Research; Johannes Kruse, Technische Universität München and German Center for Diabetes Research; Karl-Heinz Ladwig, University of Gießen and Marburg, German Research Center for Environmental Health and German Center for Diabetes Research; Wolfgang Koenig, Technische Universität München, German Center for Cardiovascular Research and University of Ulm; Annette Peters, German Research Center for Environmental Health and German Center for Diabetes Research; Wolfgang Rathmann, Technische Universität München, German Center for Cardiovascular Research and University of Ulm; and Michael Roden and Christian Herder, German Center for Diabetes Research, German Diabetes Center and Heinrich Heine University Düsseldorf.