Study: Long working hours alter brain regions tied to emotion, cognition

Editor's Note

Clocking long hours has impact beyond fatigue. It may also physically reshape the brain. As reported May 13 by CNN, that is the central finding of a new study showing significant structural brain changes in overworked individuals, particularly in areas tied to emotional regulation and executive function.

Conducted by scientists at South Korea’s Chung-Ang University and Yonsei University and published in the Journal of Occupational and Environmental Medicine, the study divided 110 healthcare workers into “overworked” and “non-overworked” groups based on whether they worked 52 hours or more per week (the country’s legal workweek cap). Those in the overworked group were generally younger and more educated, and had spent less time in their current roles, CNN reports.

The researchers used MRI neuroimaging to analyze differences in brain volume. As detailed in the article, they found that overworked participants showed increased volume in regions such as the middle frontal gyrus and the insula. These areas are critical for attention, memory, decision-making, emotional processing, and social awareness. The authors say the findings suggest a potential link between heavy workloads and neuroanatomical changes that may underlie the emotional and cognitive challenges reported by overworked individuals.

Authors say changes may be partially reversible if the environmental stressor—excessive work—is removed, although full recovery could take time. Experts cited by CNN note the small sample size and single-country focus limit generalizability, but the findings represent an important step toward understanding how overwork affects the brain on a biological level.

The outlet also connects the study to broader evidence. A 2021 WHO-ILO report found that overworking led to more than 745,000 deaths in a single year and ranked long work hours as the top occupational risk factor. While much is known about behavioral risks, this new study contributes to filling a gap in understanding the neurological mechanisms involved.