Overwork Health Risks Include Structural Brain Changes

A recent study, by Occupational and Environmental Medicine reveals that workers who log prolonged hours exhibit structural changes in brain regions responsible for executive function and emotional regulation. Using advanced neuroimaging techniques, researchers identified significant increases in brain volume among individuals working 52 hours or more per week compared to peers with standard schedules.

“These volumetric changes may represent neuroadaptive responses to chronic occupational stress and insufficient recovery,” notes the study, titled Overwork and Changes in Brain Structure, underscoring the neurological consequences of extended work periods.

The research involved 110 healthcare workers divided into overworked and non-overworked groups. Brain volume differences were analyzed using voxel-based morphometry (VBM) and atlas-based methods. Researchers applied general linear models adjusting for age, sex, and total intracranial volume, and examined correlations between weekly working hours and brain volume in regions showing significant differences.

The left caudal middle frontal gyrus was found to be approximately 19% larger in the overworked group. Additionally, 17 brain regions exhibited significantly greater volumes that positively correlated with weekly working hours. These findings remained consistent after adjusting for lifestyle factors such as smoking, drinking, and exercise.

The affected brain areas are critical for managing cognitive tasks and emotional health, which aligns with known mental health risks, including depression and anxiety, linked to excessive work hours. Experts caution that such structural changes may impair cognitive performance and increase emotional vulnerability, reinforcing the classification of overwork as a serious occupational health concern.

While the study’s cross-sectional design limits causal conclusions and its healthcare-specific sample may restrict broader applicability, it calls for longitudinal research to assess long-term effects. Moreover, it urges workplace policies to limit excessive working hours to safeguard brain health and overall well-being.

Supporting this urgency, a global analysis by the WHO and ILO estimated that working 55 hours or more per week caused 745,000 deaths worldwide in 2016, primarily from stroke and ischemic heart disease, a 29% increase since 2000. Men accounted for 72% of these deaths, with the greatest impact observed in the Western Pacific and Southeast Asia regions among workers aged 45 to 74.

WHO attributes these outcomes to physiological stress responses affecting the cardiovascular system, alongside health behaviors triggered by stress, such as smoking, alcohol consumption, poor diet, and inadequate sleep. The COVID-19 pandemic has intensified these issues, as many remote workers face longer working hours, blurring the boundaries between personal and professional time.

Tedros Adhanom, Director General, WHO, emphasized the urgency of addressing this risk, in CNN Business. “No job is worth the risk of stroke or heart disease. Governments, employers, and workers need to work together to agree on limits to protect the health of workers.”

Amid this global discussion, Mexico’s federal government plans a gradual reduction of the workweek to 40 hours, aiming to complete the transition by January 2030, according to Marath Bolaños, Minister of Labor and Social Welfare. “Reducing working hours does not decrease productivity; it dignifies workers' lives by giving them back time and valuing the work they do,” says Bolaños.

This initiative, following directives from President Claudia Sheinbaum, addresses a long-standing demand from Mexican workers and aligns with the administration’s broader agenda for structural transformation. Mexico has recently promoted policies to improve working conditions, including the Ley Silla proposal, which aims to extend rest periods during the workday, alongside the workweek reduction.

“Excessive working hours and inadequate rest and recovery periods can harm workers’ health and increase the risk of workplace accidents,” states the ILO. Among OECD member countries, Mexico bears the highest cost of free time due to the combination of long annual working hours and comparatively low wages, reports MBN. 

The proposal also addresses workers’ long commutes. In Mexico City, workers spend an average of 2.5 hours daily commuting to their workplaces. “When you add this 2.5-hour commute to an extended 9.4-hour workday, workers in Mexico City are effectively spending 12 hours a day working; that is half of their day,” reports UNAM.