How Working Long Hours Changes the Brain

What overwork does to the brain—and how to reclaim balance.

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Working long hours can pose an insidious threat to health, as the World Health Organization (WHO) reports that it led to 745,000 deaths from heart disease and stroke in just one year.

While research links overwork with poor health outcomes, the underlying biological mechanisms are unclear. However, a recent study may shed light on them, as it found that working long hours was associated with an increased size of various brain regions. This may be responsible for the cognitive and emotional challenges that frequently come with working well beyond 40 hours per week.

The findings, along with earlier research linking working long hours to a higher risk of conditions affecting physical health, such as heart disease, show the importance of work-life balance. Keeping in mind a few tips can help avoid these threats to health.

Overwork and Brain Structure

Among the participants in the study, 28 percent worked excessive hours—defined as working 52 or more hours per week.

Results showed that participants who worked excessive hours exhibited an increased volume in 17 brain regions, including a 19 percent increase in the size of the middle frontal gyrus. This area plays a major role in cognition and is associated with working memory, attention, and language processing.

Another brain region affected was the superior frontal gyrus, which is involved in planning, attention, and decision-making.

An additional region impacted was the insula, a key structure involved in regulating motor, sensory, and autonomic functions—controlled by nerves that manage involuntary processes such as heartbeat, breathing, and digestion. The insula is also linked to self-awareness, emotional processing, and understanding social context.

“The observed changes in brain volume may provide a biological basis for the cognitive and emotional challenges often reported in overworked individuals,” the researchers wrote.

The findings are eye-opening, according to Dr. Harold Hong, a board-certified psychiatrist and medical director at New Waters Recovery, who wasn’t involved in the study.

“While they found that people working long hours had a larger size of certain brain regions, bigger is not necessarily better here,” he told The Epoch Times in an email.

“It is probably a sign that the brain is under much stress and trying to cope. Although it is early research, it is a potent reminder that overworking is not just something you feel—it can leave a real mark inside your head.”

Overwork and Health Risks

Research indicates a link between overwork and increased risk of the following health conditions.

Type 2 Diabetes

A study published in the Annals of Occupational and Environmental Medicine followed more than 14,000 Korean people with prediabetes, monitoring blood sugar levels and looking for correlations with working hours. Prediabetes means that blood sugar is high, but not high enough for a diabetes diagnosis.

The authors determined that working long hours is an independent risk factor for prediabetes to develop into diabetes. Participants who worked more than 52 hours a week had a significantly higher likelihood compared with those who worked 35 to 40 hours a week.

The mechanisms that underlie the findings are not clear, but researchers have proposed several possibilities. Longer working hours may lead to negative lifestyle changes that elevate diabetes risk, including decreased exercise and increased smoking and alcohol use. Reduced exercise is also tied to weight gain, which makes progression to diabetes more likely. Additionally, longer working hours could increase stress, which disrupts the body’s use of glucose.

Cardiovascular Disease

In a meta-analysis published in Current Cardiology Reports, researchers pooled data to see whether a link exists between overwork and cardiovascular disease. A small association exists between working 55 or more hours a week and an increased risk of maladies, such as coronary heart disease and stroke. Factors underlying the association may involve an increased tendency of the blood to clot, as well as electrical instability, which refers to the system that produces and regulates heartbeats.

The WHO has concluded that sufficient evidence points to a link between long working hours and heart attacks and strokes.

Sleep Problems

A meta-analysis published in the International Journal of Environmental Research and Public Health evaluated 46 studies conducted between 1998 and 2018 to assess the strength of associations between various health conditions and overwork. The highest risk involved short sleep duration, defined as fewer than six or seven hours a day, depending on the study. The authors also noted that the findings indicate short sleep duration is a serious threat to health, as it increases the risk of chronic diseases.

The Motivation Factor

Motivation and the emotional context behind prolonged working hours could potentially influence the brain’s response, study coauthor Wanhyung Lee told The Epoch Times.

“Positive motivations, such as passion, mission-driven work, or personal enjoyment, might buffer some of the negative impacts of chronic stress. Conversely, forced or emotionally draining long hours might exacerbate adverse brain changes,” Lee said.

Hong agreed with Lee up to a point, noting that if you put in long hours because you love what you are doing or believe in the mission, your body and brain usually handle the stress better. That is because you are seeing the work as meaningful, not just as a burden. It creates more of what we call positive stress, which can feel good and push you forward.

“However, you are still human,” Hong said. “No matter how much you love your job, your brain and body will eventually show signs of wear and tear if you are not sleeping enough or taking breaks. Passion helps, but it does not make you invincible.”

Tips for Work–Life Balance

Hong offers the following tips for a healthy work–life balance:

• Set clear boundaries: Define when your workday ends—not just physically, but also mentally—and protect that time. Try to unplug from emails and work messages after hours whenever possible.
• Schedule downtime: Treat it the same way as you would a meeting. Put it on your calendar, if necessary. Whether it is an evening walk, dinner with friends, or just reading a book, treating relaxation as a priority helps you follow through.
• Listen to your body: If you are constantly drained, irritable, or having trouble sleeping, your body is telling you to slow down. Pushing through only makes things worse in the long run.
• Make time for joy: Hobbies, time in nature, exercise, or creative projects can recharge your brain in ways work never can.

“A balanced life does not just happen by accident. You build it on purpose, one small choice at a time,” Hong said.

Workplace Changes

One thing that should not be overlooked in the research is that the whole world is a society of overwork, Lee said.

“Importantly, personal efforts alone are insufficient; organizations must actively manage workloads and promote workplace cultures that emphasize health and well-being,” he said. “Employers should establish clear policies limiting excessive working hours, provide resources for stress management, and foster environments that encourage healthy work-life balance to protect their employees’ long-term brain health and productivity.”

One of the key points in a study published in BioMed Research International supports Lee’s recommendations for employers. The authors found that giving employees control over their job procedures reduced the stress of juggling work and family roles. Such control could involve measures such as the use of flexible work hours and telecommuting.

Importance of Work–Life Balance

Overwork takes too big of a toll on the entirety of life, according to psychotherapist Victoria Grinman, founder of Growing Kind Minds and The Round Table Mentorship.

As a psychotherapist and mentor who works closely with high-performing professionals and mission-driven leaders, she said she often encounters chronic overwork.

“Overwork is the socially sanctioned addiction of our time,“ Grinman said. ”We praise output but rarely pause to ask: At what cost?”

According to Grinman, chronic overwork disconnects us not just from rest, but from our relationships, our bodies, and ultimately, ourselves. The nervous system can’t distinguish between a work emergency and a life emergency, she said. It just knows that we’re in a constant state of survival, and no one can thrive from that place.

Work–life balance isn’t just about time management—it’s about energy allocation, Grinman said. When we live in alignment with our values, not just our to-do lists, we build lives that are sustainable and meaningful.

“The most successful people I work with know this: Performance follows regulation, longevity follows boundaries, and fulfillment follows the courage to hit pause,” she said.

When Life Demands More Than Balance

It’s worth clarifying exactly what work–life balance means.

“Work is a part of life, so we aren’t trying to balance work with every other part of our lives,” La Keita Carter, a psychologist at Institute for HEALing, told The Epoch Times in an email.

“Instead, we are trying to incorporate the important parts of our lives with each other by integrating work, family, volunteerism, self-care, social life, and more.”

The term “balance” implies that all of these things will be equally prioritized, Carter said, but that should never be the goal. There are times that family life takes precedence over work, she said. For example, you may have to take off time to get an older parent settled in at a new facility out of state.

“In this case, you aren’t balancing work and family. Family gets the bulk of your energy—and it should,” Carter said.

Conversely, during some scenarios or seasons of life, such as when starting a new business, it is normal to work long hours. However, normal doesn’t equate to healthy. The pressure to put a business on its feet should be tempered with the ongoing need to make time for family and safeguarding one’s health.