How working long hours may be changing your brain

Working for 52 hours or more a week changes the structure of the brain, research suggests.

Scientists have found that specific regions of the brain are altered in “overworked” people who regularly pull long working weeks.

The biggest impact is seen in parts of the brain responsible for problem-solving and memory, as well as emotional regulation.

A new study suggests that consistently working a longer week affects critical thinking and emotional responses.Credit: Getty

While the impact of “burnout” and overwork on people’s behaviour and mental health is widely recognised, researchers wanted to find out whether there were underlying neurological causes at play.

Scientists led by experts at Yonsei University in South Korea analysed the brain structures of 110 full-time workers, most of them healthcare staff, using MRI scans.

They found 32 people were working excessive hours of at least 52 hours a week, while 78 worked standard hours – typically about 40 hours. The legal limit in South Korea is 52 hours a week unless all parties agree to waive it.

‘Significant changes’ in overworked brains

Researchers used a neuroimaging technique called voxel-based morphometry to compare levels of grey matter and assess brain volume.

Scan analysis revealed those who were “overworked” 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 person’s self-awareness and understanding social context.

The researchers said: “Overworked individuals exhibited significant changes in brain regions associated with executive function and emotional regulation.”

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 ‘kills 800,000 a year’

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 “preliminary evidence that overwork is associated with structural brain changes, particularly in regions linked to cognition and emotion”.

They added: “These 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.

“The results underscore the importance of addressing overwork as an occupational health concern and highlight the need for workplace policies that mitigate excessive working hours.”

In Britain, the legal maximum for a working week is 48 hours.

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.

“Global 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,” she said.

“A long-hours culture can be experienced in what we’ve identified as the ‘small print’ of working life today.”

She added that a YouGov survey had found 44 per cent of employees said working beyond their contracted hours was part of their workplace’s culture, and more than half “regularly check work emails and messages outside of working hours”.

The research findings were published in the journal Occupational and Environmental Medicine.

The Telegraph, London

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