Working 52+ hours weekly? It could alter your brain structure
14 May 2025

A recent study has revealed that working long hours can significantly change the brain's structure.

The research was conducted by scientists from South Korea's Chung-Ang University and Yonsei University. They studied 110 healthcare workers, dividing them into "overworked" and "non-overworked" categories.

In South Korea, where a 52-hour work week is the legal maximum, overworking has become a major public health issue.

Study participants and methodology
Research details

The "overworked" group included 32 people who worked 52 hours or more every week.

This group was on average younger, in employment for less time, and more highly educated than their standard-hour counterparts.

The researchers used a neuroimaging technique to analyze the workers' brain volume, utilizing MRI scans to identify differences in gray matter levels across different brain regions.

Brain regions impacted by overworking
Neuroplasticity

The study found notable changes in brain regions associated with executive function and emotional regulation, among those who worked 52 hours or more per week.

Areas that exhibited increased volume included the middle frontal gyrus, important for cognitive functions, attention, memory and language-related processes.

The insula also exhibited increased volume, which is involved in emotional processing, self-awareness and understanding social context.

Potential reversibility of brain changes
Reversibility

Joon Yul Choi, co-author of the study and an assistant professor at Yonsei University's Department of Biomedical Engineering, said these changes might be "at least in part, reversible" if environmental stressors are eliminated.

However, returning to the brain's baseline state could be a lengthy process.

This indicates a possible connection between increased workload and changes in certain parts of the brain.

Long working hours linked to health risks
Health concerns

Previous research has also underscored the adverse health effects of long working hours.

A 2021 joint study by the International Labour Organization (ILO) and the World Health Organization (WHO) estimated that overworking resulted in over 745,000 deaths every year.

Long hours have been linked to a higher risk of diabetes in women and a decrease in cognitive ability.

Need for more research
Further investigation

Frank Pega, who led the WHO-ILO 2021 study, said that these latest findings provide "important new evidence" that could help understand how long working hours "radically" impact physical health.

He stressed the need for more studies in different populations as this study had a small sample size and focused only on healthcare workers in South Korea.

Call for action to protect workers' health
Protective measures

The study's authors emphasized the need to tackle overwork as an occupational health issue.

They recommended that governments, employers, and workers alike can take steps to shield workers' health from long hours.

Jonny Gifford, principal research fellow at the Institute for Employment Studies in Brighton, England, said this research "confirms some physiological reasons that working long hours affects our wellbeing."