Scan analysis revealed those who were βoverworkedβ had a 19 per cent increase on average in the volume of their left caudal middle frontal gyrus, which has a major role in several cognitive functions, particularly in the frontal lobe. It is involved in attention, working memory and language-related processing.
The scans also showed an increase in volume across 17 regions of the brain including parts responsible for attention, planning and decision-making, as well the insula, which has a key role in integrating sensory and motor functions, processing emotions, a personβs self-awareness and understanding social context.
The researchers said: βOverworked individuals exhibited significant changes in brain regions associated with executive function and emotional regulation.β
But they noted it was not possible to determine whether these structural changes were caused by working long hours, or gave the individuals a predisposition to work longer hours.
Also, those putting in long working hours each week were significantly younger, had spent less time in work and were more highly educated than those clocking up standard hours.
Overwork βkills 800,000 a yearβ
Regularly working long weeks has previously been linked to increased risk of heart attack, stroke and mental health issues.
The impact of stress from overworking increases the production of cortisol, raises blood pressure and weakens the immune system.
Other studies have found that overwork, and the resulting stress, can lead to impaired sleep, depression, heavy drinking, poor memory and heart disease.
The study analysed the brain structures of 110 full-time workers, mostly from the healthcare sector, using MRI scans.Credit: iStock
The International Labour Organisation estimates that overwork kills more than 800,000 people a year, the researchers noted.
The research team concluded that the study provided βpreliminary evidence that overwork is associated with structural brain changes, particularly in regions linked to cognition and emotionβ.
They added: βThese findings provide novel neurobiological evidence linking prolonged working hours to structural brain changes, emphasising the need for further research to understand the long-term cognitive and emotional implications of overwork.
βThe results underscore the importance of addressing overwork as an occupational health concern and highlight the need for workplace policies that mitigate excessive working hours.β
In Britain, the legal maximum for a working week is 48 hours.
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Ruth Wilkinson, head of policy and public affairs at the Institution of Occupational Safety and Health charity, said almost a quarter of Britons were regularly working more than that.
βGlobal analysis from the World Health Organisation and International Labour Organisation has found that working long hours is on the increase and is responsible for about one-third of the total estimated work-related burden of disease,β she said.
βA long-hours culture can be experienced in what weβve identified as the βsmall printβ of working life today.β
She added that a YouGov survey had found 44 per cent of employees said working beyond their contracted hours was part of their workplaceβs culture, and more than half βregularly check work emails and messages outside of working hoursβ.
The research findings were published in the journal Occupational and Environmental Medicine.
The Telegraph, London
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