James' World 2

People who were overworked showed changes in 17 brain regions compared to those who worked typical hours. These differences included areas responsible for executive functions like logical reasoning, as well as managing emotions.

Lee says the results surprised him, in part because they suggest that the brain changes in response to stress and anxiety, with some potential negative consequences. “We anticipated that prolonged stress from overwork would affect brain structure, but finding increased volume in certain brain areas was somewhat unexpected,” he wrote in an email to TIME. “Our results suggest a potential neuroadaptive response, meaning the brain might initially try to compensate for increased cognitive and emotional demands. These surprising findings underscore the complexity of how the brain responds to prolonged occupational stress.”

Advances in brain imaging now make it possible to detect even small volume differences, Lee says. “These technological breakthroughs have empowered researchers to explore previously invisible biological changes induced by prolonged stress or excessive workloads, thus opening up an entirely new dimension in occupational and environmental health research.”

The changes his team identified involve areas of the brain that are responsible for things like memory, decision-making, attention, planning, and problem-solving. “Changes here could impact a person’s ability to efficiently manage tasks, make decisions, and maintain concentration,” he says.

Differences in other areas could affect how well people regulate emotions; the changes they saw may indicate less emotional stability, increased anxiety, and problems interpreting emotional cues or managing interpersonal connections.

Would reducing workload alleviate or reverse some of these changes? It’s too soon to know if these alterations are permanent, Lee says. “Longitudinal studies will be essential to understand if these brain structural changes are reversible or persist long-term.” He plans to follow up this study with longer-term data and larger populations to determine what happens to these brain changes over time, and whether adjusting workloads can reduce or reverse them.

In the meantime, there are things people can do to alleviate some of the negative effects of overwork on their health, even if they can’t adjust their hours. Getting enough sleep and physical activity, as well as addressing stress with mindfulness or relaxation techniques, can help. But Lee says the burden shouldn’t rest entirely on employees. Businesses should limit excessive working hours, provide stress-management resources, and promote work-life balance “to protect their employees’ long-term brain health and productivity.”