The city-government worker was just getting the hang of his job when a new hire upended everything. She became his mentee, and she asked him if he could put together a manual on how to do her work. He told her okay, but begrudgingly. The manual was a good idea in theory, but he was busy, and he wished she could just learn through observation, as he had.

Over the next months, as he dealt with more immediate deadlines, the worker kept pushing the manual off. His new colleague grew frustrated. “All day, morning and evening, she kept asking me, ‘When will the manual be ready? When will the manual be ready?’” the worker told me through an interpreter.

The manual was a mundane request, but it made him feel confused and powerless. He didn’t know how to communicate to the new colleague that he didn’t have the time and the job was difficult. Repeated over and over, her request caused his anxiety to ratchet up to extreme levels. He hesitated to delegate work to her, which meant that he took on even more. He started having problems sleeping and eating.

Finally, the worker says, he went to lunch with his boss to discuss the situation. His boss assured him that it wasn’t his fault and asked him to work on the manual as best he could. Still, when he came back to the office, he could see the new colleague giving him the side-eye. Later, she asked him why she hadn’t been invited out, too.

That evening, the worker went home and collapsed in his living room. He felt like he couldn’t go to work anymore. The next day, his wife took him to the hospital, where he was diagnosed with depression. He was allowed to take a hiatus from his job for a few months. After graduating with a degree from a prestigious state-run university, he couldn’t believe what was happening to him.

The worker was one of a few patients in similar situations introduced to me by Takahiro Kato, a neuropsychiatry professor at Kyushu University in Japan. (Kato requested anonymity for the patients to maintain their privacy and protect them from repercussions at work.) Kato believes that these patients’ distress is an example of an emerging condition that he refers to as “modern-type depression.” At its heart, the condition is a struggle by some workers to learn how to assert themselves in a social context where they have little practice. And its reach might extend far beyond Japan.

Aside from a few researchers, most mental-health professionals in Japan don’t use the term modern-type depression. It isn’t a clinical diagnosis, and despite its “modern” tag, characteristics of the condition likely have always existed alongside other forms of depression. The term first gained prominence in the 1990s, when Japanese media seized on it to portray young workers who took time off from work for mental-health reasons as immature and lazy.

While the term still carries stigma, Kato believes it’s useful to examine as an emerging cultural phenomenon. In the West, depression is often seen as a disease of sadness that is highly personal. But in Japan, it has long been considered a disease of fatigue caused by overwork. The traditional depressed patient has been a “yes man,” someone who always acquiesces to extra tasks at the expense of his social life and health. What makes modern-type depression different, according to Kato, is that patients have the desire to stand up for their personal rights, but instead of communicating clearly, they become withdrawn and defiant.

Clinically, this type of behavior first started to appear with some frequency in the work of Shin Tarumi, a colleague in Kato’s department at Kyushu University. In the early 2000s, Tarumi noticed that some of his younger depression patients, particularly those born after 1970, had an entirely different personality profile than traditional depression patients. They didn’t try to maintain harmony at the expense of themselves, and they had less loyalty to social structures. Instead, they avoided responsibility. They tended to fault others for their unhappiness.

Several years after Tarumi died, Kato took over the line of research based on his own clinical observations. There are no definitive statistics on the prevalence of this type of patient. Patients exhibiting these characteristics tend to be middle class. Most are men, because men are more likely to seek professional help in Japan. There’s no connection to a particular type of job, because the issues patients face are mostly interpersonal. What they do share are similar personality traits and social conditions.

Kato connected his findings about these patients to Japan’s public discourse around modern-type depression because he found the term useful for exploring a fairly recent cultural flux. Modern-type-depression patients, Kato believes, are in an uncomfortable limbo state, trained to be dependent in their family and social lives and unclear on how to adapt to a quickly evolving company culture that asks them to be more assertive. While they want to speak up for themselves, their ways of going about it are ineffective and immature.

Read: The social contradictions of Japanese capitalism

One patient Kato introduced me to was a 34-year-old engineer. At first, the engineer was happily employed at a government office, but he says he was transferred against his wishes to another known for its long hours. He repeatedly asked if he could be moved again, but his supervisor told him it was impossible. He lost his motivation. Months after he started asking, he was finally granted the transfer, but it was too late for him to snap out of his withdrawn state. When we spoke, the engineer was in the middle of a long hiatus from work.

Kato has found that a variety of disruptive changes in Japanese culture, from childhood through the workplace, have made it difficult for many workers to adjust to a corporate ethos in the country more and more based on Western individualism. He lays out these causes in two papers in the journals Psychiatry and Clinical Neurosciences and American Journal of Psychiatry.

Japanese parenting is one major factor. As Japan focused on rebuilding economically after its defeat in World War II, Kato observes, men were busy working and mostly absent, so the culture began promoting the ideal of the nurturing, even coddling, mother. The mother-child bond became symbolic of the Japanese behavioral pattern of amae, a desire by children to be loved and act self-indulgently well into adulthood. While some psychologists have promoted the importance of this nurturing relationship, others say that, taken to extremes, it discourages children from becoming autonomous adults.

Kato believes that this problem of dependence was compounded by Japan’s education structure. In the 1970s, the government education system deemphasized competition and focused more on allowing students to develop their own interests. This approach, called yutori kyōiku, was a huge contrast to the strict schooling that had led to Japanese success in the past. Today, yutori is widely criticized for bringing down the overall rigor of Japanese education. Some blame the idea itself, and others believe that it was just implemented incorrectly. Either way, the more relaxed system offered fewer opportunities to contend with demanding authority figures or competition from peers.

As Kato explains, many who were brought up within this environment had a major wake-up call when Japan’s economy hit a period of stagnation in the 1990s. At work, they faced an older, paternalistic model of leadership and had to put up with heavy criticism from bosses. In the past, unending diligence under such pressures would at least lead to senior positions; job stability was pretty much guaranteed as the country experienced years of steady economic progress. But the rupture of the bubble economy meant that this silver lining had disappeared.

Read: What Americans should understand about Japan’s 1990s economic bust

To keep a job, it was no longer sufficient to follow basic orders. Now workers had to prove themselves as individuals, and many had never developed that skill. It was especially hard on those whose personalities tended to be withdrawn or less socially skilled, who might have been able to fly under the radar in the past. Some simply gave up. “Modern-type-depression patients are living out the consequences of a nation transitioning from a culture of collectivism, in which they have to accept their rank within a family, to a capitalistic workplace where they have to forge their own path,” Kato says.

Modern-type depression does not seem to be isolated to Japan. In a 2011 study, Kato surveyed 247 psychiatrists, half of them from Japan and half from eight other countries, including Australia, Bangladesh, and South Korea. He gave the psychiatrists two case vignettes resembling traditional and modern-type depression, and found that both descriptions were familiar to many of the participants.

Based on these doctors’ replies, modern-type depression appears to be most prevalent in urban areas within collectivistic cultures that are experiencing rapid socioeconomic changes. Taiwan, another collectivist society that has rapidly urbanized, had an even higher rate of such cases than Japan; Bangladesh and Thailand also had a high prevalence. As cultures around the world adapt to a globalized workplace, this psychologically demanding adjustment might be in store for many more workers, which could lead to a wave of mental-health troubles that psychologists so far don’t know how to treat. (The same pattern might appear in immigrant populations who move from a country with a collectivist culture to the West, though Kato has not yet looked at such examples.)

In Japan, some researchers remain concerned about continuing to use the term modern-type depression. Junko Kitanaka, a medical anthropologist at Keio University, worries the historical stigma that comes with the label unnecessarily pathologizes young people’s dissatisfaction at work, when it would be more helpful to build a workplace culture in which they can thrive. “If it’s used to better understand workers’ psyche and the genesis of depression, then it’s good,” she says. “But I don’t think it is used that way in general discourse. It is used in a way that places blame unnecessarily on the individual worker’s personality.”

So far, no medical consensus exists on therapeutic interventions for the condition, whatever it’s called. While efforts to normalize depression in Japan have led many people to seek treatment, Kitanaka says that the country still needs to educate people about the many different forms depression can take beyond the current stereotype of self-sacrifice. Kato has proposed that psychosocial interventions such as group therapy and changing companies’ work environments should be the primary treatment strategies, because medication has shown itself to be less effective for modern-type depression.

Kato is currently studying 400 patients long-term to see what protocols work best. In the meantime, one therapy he recommends is Rework, a program that Tsuyoshi Akiyama, a psychiatrist at NTT Medical Center in Tokyo, started for treating conventional workplace depression. More than 220 clinics in Japan use it. The program is run as an imitation workplace, where participants do readings, have discussions, play sports, and work out puzzles with one another. Trained staff members watch and give them ideas about where their interpersonal problems might lie and how to work more effectively.

The city-government worker I spoke with who struggled with writing the manual for his colleague is one beneficiary of Rework. After returning to his job, he had a hard time adjusting, because he felt everyone was handling him with kid gloves. He couldn’t find a way to reassure them he was okay, and all of his overthinking about the situation made him lag behind and relapse. Through Rework, he began to see that he needed to start simply doing the work instead of getting caught up in the social dynamics.

Today, he says, if a co-worker asked him to make a manual, he wouldn’t blame himself so much if he couldn’t get it done. He would simply state what his limits are. “I was hesitant before to talk to someone who I didn’t want to communicate with,” he says. “Now if I have a difficult colleague, I can handle it.”