For many years, researchers have noticed a common pattern when it comes to how happy or unhappy people feel throughout life.
People tend to feel okay in childhood, then become more stressed, worried, or even depressed as they move through their 30s and 40s.
This “unhappiness hump” usually peaks around age 50, and then happiness slowly begins to return in later life. This U-shaped curve of well-being has been seen in countries all over the world, both rich and poor.
But a new study now suggests that this pattern may have completely changed. A team led by David Blanchflower from Dartmouth College in the United States has found that the midlife unhappiness peak has disappeared. The results were published in the journal PLOS One in August 2025.
The researchers looked at a large amount of data to better understand what’s happening. They first analyzed surveys from more than 10 million American adults, collected between 1993 and 2024 by the Centers for Disease Control and Prevention.
They also studied responses from the UK Household Longitudinal Study, which has tracked 40,000 households in the United Kingdom from 2009 to 2023.
What they found was surprising. The so-called “unhappiness hump” no longer appears in either country. In fact, it seems that younger people are now more likely to report feeling depressed, anxious, and unhappy than older people.
The older age groups didn’t change much, but the mental health of young adults has declined significantly. This shift caused the old U-shape to flatten and even flip.
To see if this pattern was happening in other countries, the researchers also examined nearly 2 million responses from people in 44 countries, gathered through a project called Global Minds between 2020 and 2025.
Again, the same trend showed up—young people are now reporting more mental health struggles than middle-aged or older adults. This shift seems to be happening around the world.
But why is this happening? The researchers don’t have one clear answer. Instead, they offer several possible reasons. One is the long-lasting effect of the Great Recession, which may have made it harder for younger people to find good jobs and feel financially secure.
Another reason may be that mental health services, especially for young people, are not well funded or easy to access. The COVID-19 pandemic also had a big impact, increasing stress and isolation. And then there’s social media, which has become a bigger part of daily life and may be harming young people’s mental well-being.
This study is one of the first to show such a major shift in how mental health changes with age. According to the authors, the most important finding is that younger people today are struggling more than ever before. In the past, people expected life to get harder during middle age, but now, many are facing these feelings much earlier in life.
The researchers hope their findings will lead to more awareness and better support systems for young people who are struggling. They also call for more research to better understand why this change is happening and what can be done to help.
In conclusion, this study provides strong evidence that the traditional pattern of happiness through life may no longer apply. Mental health challenges are now hitting younger generations the hardest, and this shift needs urgent attention from health professionals, educators, and policymakers.
For more health information, please read studies that one sleepless night can reverse depression for days and scientists find better treatment for older adults with depression.
For more about mental health, please read studies about Middle-aged women with no kids may have this mental issue and findings of scientists find a cause of mental illnesses induced by childhood abuse.
The study is published in PLOS ONE.
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