Can Long Working Hours Alter Brain Structure? Study Finds Out

New Delhi: Working long hours could lead to structural changes in the brain, particularly in regions linked to emotional regulation and executive functions like memory and problem-solving, according to preliminary research published in Occupational & Environmental Medicine. The study adds to growing evidence that overwork poses serious health risks, potentially extending to cognitive and emotional well-being.

Previous research has linked prolonged work hours to increased risks of cardiovascular disease, metabolic disorders, and mental health problems. The International Labour Organization (ILO) estimates that overwork claims more than 800,000 lives globally each year. While the behavioural and psychological effects of overwork are relatively well documented, this new study explores the less-understood neurological and anatomical impacts.

Researchers conducted structural brain volume analysis using data from the Gachon Regional Occupational Cohort Study (GROCS) and MRI scans from a separate project on working conditions. A total of 110 healthcare workers, most of them clinicians, were included in the final analysis. Of these, 32 routinely worked 52 or more hours per week—classified as long working hours—while 78 worked standard hours.

Those working longer hours tended to be younger and more highly educated and had spent less time in the workforce compared to their standard-hour counterparts. Brain volume differences were analyzed using voxel-based morphometry (VBM) and atlas-based analysis, both advanced neuroimaging techniques.

The results revealed significant differences in grey matter volume in key brain regions among those logging long hours. Notably, there was a 19% increase in the volume of the middle frontal gyrus—an area associated with attention, working memory, and language processing. Voxel-based morphometry also identified peak volume increases in 17 brain regions, including the superior frontal gyrus, involved in planning and decision-making, and the insula, which processes emotion and self-awareness.

While these findings suggest a potential link between overwork and changes in brain structure, the researchers caution that the study is observational and cannot establish causation. They also note that it remains unclear whether these brain changes are a result of long hours or pre-existing traits that influence work habits.

Researchers said, “While the results should be interpreted cautiously due to the exploratory nature of this pilot study, they represent a meaningful first step in understanding the relationship between overwork and brain health.”

They add, “Notably, the increased brain volumes observed in overworked individuals may reflect neuroadaptive responses to chronic occupational stress, although the exact mechanisms remain speculative.”

Reference: https://oem.bmj.com/content/early/2025/05/08/oemed-2025-110057