Global Study Shows Unhappiness Hump Has Vanished With Age todayheadline

A familiar pattern in mental health has disappeared. A new study finds the so-called unhappiness hump, a midlife peak in worry and despair, no longer exists. Instead, mental ill-being now falls steadily with age, with young people reporting the worst outcomes.

The analysis, led by David Blanchflower of Dartmouth College and colleagues in the U.S. and U.K., appears in PLOS One and draws on data from over 12 million survey responses across 44 countries between 1993 and 2025.

From U-shape to straight line

For nearly two decades, researchers observed a U-shaped curve in wellbeing. Happiness declined from childhood until about 50, then rebounded in older age. Its mirror image was the ill-being hump, where stress, depression, and despair peaked in midlife before easing later. That steady pattern, replicated in hundreds of studies, has abruptly shifted.

In U.S. data from the CDC’s Behavioral Risk Factor Surveillance System, covering more than 10 million adults since 1993, and in the U.K.’s Household Longitudinal Study, the hump flattened out. Mental health among people in their 40s and older has barely changed. Instead, worsening youth mental health has reversed the curve. By 2023, despair was highest among those under 25, especially young women, and lowest among the oldest surveyed. Similar results emerged from the Global Minds Project, which tracked nearly 2 million people in 44 countries between 2020 and 2025.

“Ours is the first paper to show that the decline in young people’s mental health in recent years means that today, both in the United States and the United Kingdom, mental ill-being is highest among the young and declines with age.”

Why youth mental health is falling

The reasons are murky. The authors point to the long shadow of the 2008 financial crisis, which scarred job prospects for young workers. They cite chronic underfunding of mental health care systems. They note the isolating effects of COVID-19 and its school closures. And, not least, they highlight the role of smartphones and social media in reshaping how young people see themselves and others. All of these forces may be feeding the trend, but untangling them remains a challenge.

Other data underscore the crisis. U.S. suicide rates among teens rose 70 percent between 2008 and 2020. Antidepressant prescribing doubled for U.K. children between 2005 and 2017. Teachers in U.S. schools now identify anxiety and depression as major barriers to learning. Chronic absenteeism, linked closely to mental distress, surged after the pandemic. In each metric, the youngest show the steepest decline.

“This is a huge change from the past when mental ill-being peaked in middle-age. The reasons for the change are disputed but our concern is that today there is a serious mental health crisis among the young that needs addressing.”

Global implications

The disappearance of the unhappiness hump is not just a statistical quirk. It matters for policy and public health. For decades, researchers and governments treated the midlife crisis as a predictable phase, something most people recovered from. Now the crisis point has shifted downward in age, to those least equipped with resources and coping strategies.

What comes next depends on whether societies treat this as an urgent crisis or a passing generational wave. If the pattern holds, then today’s young adults may carry scars that affect health, work, and family life for decades. The decline is not uniform either—young women consistently report worse outcomes than men across all 44 countries. That gender gap is widening.

A vanishing shape, a new concern

The study closes with a stark reminder: mental ill-being no longer rises and falls with midlife but instead declines steadily with age. The unhappiness hump has disappeared, replaced by something more unsettling. Old age no longer looks like the relief from a storm. It looks like calm compared to the turbulence of youth.

PLOS One, DOI: 10.1371/journal.pone.0327858