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Mondays Really Are More Stressful

Scientific American

January 2026

The start of the workweek can be a biologically measurable stressor, with consequences for long-term health that can stretch into retirement

FOR DECADES THE TERM “MONDAY BLUES” has been shorthand for the collective groan that greets the start of each workweek. It’s also well documented in medical statistics. Mondays come with higher rates of anxiety, stress and even suicide compared with other days. Studies on the phenomenon across entire countries have found a 19 percent increase in the chance of sudden cardiac death from confirmed heart attacks and other cardiovascular events on Mondays, affecting both men and women across age groups.

It now turns out that the effect of Mondays can extend well beyond fleeting fluctuations in mood. One of us (Chandola) recently discovered that people who report feeling anxious on Mondays show evidence of heightened activity in the body’s stress-response system over months. More surprising, this effect persisted among older adults who were no longer in the workforce, suggesting that, for some people, the stress of Mondays is a lifelong burden.

The biological underpinnings of the “Monday effect” have long been unclear, however. Is the type of stress and anxiety experienced on Monday biologically distinct? And could it be leaving a mark on the body even after people stop working?

To answer these questions, Chandola focused on the stress hormone cortisol. The hypothalamic-pituitary-adrenal axis, a central stress pathway linking brain and body, manages much of people’s response to stress. When we experience a stressor—whether it’s something psychological, such as a looming deadline, or physical, such as a biting cold morning—our brain triggers the release of cortisol. The hormone helps us manage short-term stress by mobilizing energy and sharping focus. But chronically high levels of cortisol disrupt the brain and bodily systems, impairing immune function and increasing the risk of anxiety, depression, cardiovascular disease, diabetes and obesity.