Mental health has become one of the defining concerns of contemporary public debate. Rising anxiety, burnout, and depression are often presented as symptoms of a society in decline, particularly among younger generations. But Jos van Leeuwen's research at the EUI Department of Political and Social Sciences tells a more uneven story – and, in some places, a more hopeful one.
At the centre of his work is a question he describes as deceptively simple: "Are people really becoming more depressed, stressed, or burned out in modern society?" Answering it raises a second problem. "If this is true, what has caused this change?" For van Leeuwen, those causes cannot be found by looking only at individuals.
With a background in sociology, clinical psychology, and philosophy of science, van Leeuwen has long been dissatisfied with explanations that isolate mental distress from its social environment. Clinical psychology, he argues, focuses too much on the individual. "It's very based on Western ideas of what is a disorder, what is a depression, and also what kind of symptoms belong there. It's also focused very much on the individual processes going on in the brain," he says. "You have a depression, that means you have negative thoughts, maybe some dysfunctional cognitive patterns, but it doesn't really wonder so much about where it comes from." Sociology, by contrast, excels at analysing inequality and institutions but has "always kind of lacked the real attention to what is going on inside individual’s minds, or at least the real knowledge about it." He continues, "What I always tried to do was ask how these actually interact; how to bring them together; how to bridge the gap between the very macro level of society, social institutions, social groups, and the micro level of the individual experience."
That interdisciplinary approach has shaped his doctoral work at the EUI, where he has confronted what would become a central methodological challenge: the age-period-cohort (APC) identification problem. "If I compare a 20-year-old with a 30-year-old in the year 2020, I might see that the 20-year-old is a bit more depressed," he explains. "I could say this is an age thing – that age 20 is simply a harder time of life. But, it could also mean there's a generational change, because those people don't just differ by 10 years in age, they also differ by 10 years in when they were born." The mathematical identity makes it nearly impossible to disentangle whether differences in mental health reflect aging, the period people live through, or the generation they belong to.
Researchers have grappled with this puzzle since the 1950s. Solutions emerged, only to be debunked years later. "Every time they thought they'd found the holy grail, a couple of years later somebody would show that, no, actually it doesn't work," van Leeuwen says. Simulation studies revealed that the methods often produced exactly the wrong answer, confusing generational effects with aging or vice versa.
Van Leeuwen spent his first three years at the EUI investigating different approaches to APC analysis and testing them on data from individual countries. The work was intellectually absorbing but also exhausting. "It can really break your brain," he admits. Once the methodological framework was established, the empirical findings proved striking.
Using longitudinal data from 24 countries, van Leeuwen compared mental health trajectories across cohorts and national contexts. In high-income Western countries, like the UK, the US, the Netherlands, and Germany, younger generations report worse mental health than earlier cohorts did at the same age. "In those countries on the top of the world economy, there you see the most negative changes going on," he says. But, this pattern is far from universal.
"In a lot of emerging economies, you actually see the opposite," he says. Poland stands out as a clear example. "The more recent generations are actually doing a lot better." Young adults there report better mental health than previous generations, even when compared at identical ages. South Korea shows a similar pattern, a result that initially surprised him. "Nowadays we think of South Korea as one of the highest developed countries in the world. We also have this idea that people are very stressed there, and that their suicide rates are extremely high, which is all true. But, if you compare to what happened there before, it was way worse."
To understand why, van Leeuwen points to long-term political and economic trajectories. "Until the 1980s, South Korea was poorer than North Korea. They were completely destroyed in the Korea War," he explains. The country languished under a dictatorship while the North received substantial Soviet and Chinese investment. But once economic development took off, everything changed. "Every year things got so much better that people started to feel like life is indeed getting better and they don't need to worry anymore. Maybe they cannot afford something now, but next year they will be able to." Poland's post-1990 transformation followed a similar arc, with some of the highest GDP growth in the world. The combination mattered. "People's life quality went up a lot because they have more money to spend on healthcare, on education,” he explained. “And, on the other hand, they also became politically free."
Van Leeuwen's interpretation comes down to two factors: material well-being and political freedom. Not just having them, but gaining more of them. "In the end it actually boils down to some very simple things," he says. The pattern reflects what economists call the Easterlin Paradox. "The Easterlin Paradox says that absolute differences in material resources don't help to explain differences in happiness, but changes - they matter," he explains. Western countries may still be wealthier, but their populations have grown accustomed to prosperity. "We have been used to being so rich for such a long time that we don't really see it anymore. We actually start to feel like things are not getting better anymore. They’re maybe staying at the same level, or even going down a bit." In emerging economies experiencing rapid development, by contrast, each year brings tangible improvements that foster optimism about the future.
The research also revealed that mental health decline in the West isn't uniform across all age groups. "It's really people born in the 1990s or in the 2000s who are bearing the heaviest load of all these changes," he notes, while older generations remain relatively stable.
One of the most important implications is that mental health decline is not inevitable. "I can actually show that there are areas in the world, there are specific societies where things are pretty positive," van Leeuwen says. "This can also give us hope." Some societies demonstrate that improvement is possible, even under pressure.
Depression and burnout carry a cost. "Mental health issues have a high social cost. If people are depressed, they are less productive. They will need a lot of mental health services, so it will take a lot of money and investment to actually get them back on track," he says. They are also difficult to reverse. "Depression is a very sticky thing. As soon as you have a depression or a burnout, you reach this kind of tipping point and it takes a lot of effort, time, and patience to get people back to their normal productive state." By avoiding that tipping point through economic stability and opportunities for young people, he argues, prevention proves far more efficient than treatment.
Van Leeuwen hopes his work will reach audiences beyond academic journals. His research resonates widely precisely because it speaks to lived experience. "When I describe it to somebody, they already have an idea like, oh yeah, are you talking about this? Did you also think about that?" he says. "It's not just an academic ivory tower. It's something most people will have an idea about." Mental health, he believes, is a shared social concern. His research directly challenges the narrative that young people are simply "snowflakes" who "complain about everything," as he puts it. By revealing clear social patterns, his work demonstrates that these struggles reflect measurable changes in economic and political conditions, not character flaws.
He remains committed to academic research that bridges individual experience and social structure. His findings offer a clear conclusion: Mental health patterns track political and economic trajectories with remarkable consistency. The crisis dominating Western discourse is not universal or inevitable. It reflects specific conditions – stagnation, precarity, diminished opportunity – that policy can address.
Frans Johannes Van Leeuwen, from the EUI Department of Political and Social Sciences, has recently defended his PhD thesis ‘Mental health in modern society: life course and social change in mental wellbeing in a global perspective’, supervised by Professor Juho Härkönen. He is now a research associate at the Department. See also his latest publication, ‘Mental Health in China: Social Change in Life Course Trajectories.’