Putting in excessive hours at work may do more than leave people feeling exhausted. New research suggests it could be physically altering the brain.
A study published in Occupational & Environmental Medicine links chronic overwork to structural changes in areas responsible for regulating emotions and managing tasks such as memory, attention, and planning.
Researchers examined the brains of healthcare professionals, some of whom regularly worked 52 hours or more per week. Using neuroimaging techniques, including voxel-based morphometry and atlas-based analysis, they compared those working long hours with peers who kept to standard schedules.
The study drew on data from the Gachon Regional Occupational Cohort Study, focusing on 110 participants. Among them, 32 individuals were identified as regularly working extended hours. This group tended to be younger, more educated, and had spent less time in the workforce overall compared to those working standard hours.
The brain scans showed notable differences. Participants with longer working hours displayed increased grey matter volume in several regions, including the middle frontal gyrus (an area associated with working memory and language) and the superior frontal gyrus, linked to attention and decision-making.
Another affected region, the insula, plays a role in emotional awareness, social perception, and processing signals from the body.
These findings suggest the brain may be adapting to prolonged occupational stress, although the long-term impact of these changes remains unclear. Researchers caution that this was a small observational study and cannot establish direct cause and effect. It also remains uncertain whether these differences reflect a response to overwork or pre-existing traits among individuals more likely to take on longer hours.
What is clear, however, is that the mental strain of overwork may be accompanied by physical changes in the brain.
This research adds to a growing body of evidence linking long hours to health risks, including heart disease, metabolic disorders, and mental health issues. The International Labour Organization has previously estimated that overwork contributes to more than 800,000 deaths globally each year.
Though more in-depth, long-term studies are needed to confirm the brain changes and their consequences, the current findings support concerns about the cognitive and emotional toll of extended working hours.
Researchers suggest that employers and policymakers should take these early indicators seriously and consider strategies to limit excessive workloads in order to protect both brain and overall health.
