A recent study published in Occupational & Environmental Medicine has revealed that overwork causes significant adverse changes to brain structure, reinforcing the need for workplace policies that limit excessive working hours. The findings from this study align closely with the research by the World Health Organisation ongoing work at the Opus Centre, which has been highlighting the pressing need to addressing psychosocial risks and their impact on cognitive health and workplace wellbeing.
Key Findings from the Study:
- Participants: 110 healthcare workers were studied, comparing those working ≥52 hours per week with those on standard schedules.
- Results: The overworked group showed notable increases in brain volume in regions responsible for executive function and emotional regulation—specifically the middle frontal gyrus, insula, and superior temporal gyrus. These changes may reflect neuroadaptive responses to chronic stress and sleep deprivation, potentially explaining the cognitive and emotional difficulties often reported by overworked individuals.
Psychological Erosion Effect
The Opus Centre has introduced the concept of the “psychological erosion effect”—a gradual decline in mental health and cognitive capacity due to sustained exposure to psychosocial hazards at work. This concept directly supports the study’s conclusion that long working hours can lead to neuroadaptive changes in the brain, impacting emotional regulation and executive function (Psychological Erosion: A Modern-Day Disease | The Opus Centre)
Workload and Work Addiction
The Opus Centre has explored the concept of work addiction—a compulsive need to work that mirrors addiction behaviours and is linked to emotional stress and perfectionism. This aligns with the study’s suggestion that overwork may be driven by occupational stress and sleep deprivation (Global research survey aims to better understand work addiction – ABC News).
Policy and Practice Recommendations
The Opus Centre’s Psychosocial Safety Hierarchy of Control includes job design, leadership support, and recovery strategies as key levers for mitigating psychosocial risks. These are precisely the types of interventions the study calls for including policies that protect against excessive hours and support to address cognitive and emotional demands.
Implications for Employers:
- The findings provide a biological basis for the mental health risks associated with long working hours.
- Overwork is now recognised as a critical public health issue, with the International Labour Organization attributing over 800,000 deaths annually to long hours.
- The study underscores the need to:
- Address long hours and cognitive demands as a key determinant of psychological health
- Develop interventions that protect mental and promote wellbeing
References:
Manfield, E. (2023, April 13). Global research survey aims to better understand work addiction. ABC News. https://www.abc.net.au/news/2023-04-13/global-survey-research-into-work-addiction/102212352
Jang, W., et al. (2025, May). Overwork and changes in brain structure: A pilot study. Occupational and Environmental Medicine. https://doi.org/10.1136/oemed-2025-110057
World Health Organization. (2021, May 17). Long working hours increasing deaths from heart disease and stroke: WHO, ILO. https://www.who.int/news/item/17-05-2021-long-working-hours-increasing-deaths-from-heart-disease-and-stroke-who-ilo