Only 34% of global workers describe themselves as “thriving” according to a new report from workplace analytics company Gallup—down one percentage point from the year prior. But the proportion of staffers under the age of 35 who say they’re thriving dropped to 31% in 2023, compared to 35% the year before. That means that young employees have the lowest percentage of flourishing workers, and have also experienced the biggest drop in morale. About 20% of global staffers surveyed also said they felt lonely, compared to 22% of staffers under 35, according to the report. 

Jim Harter, chief scientist of workplace and wellbeing at Gallup, tells Fortune young workers’ mental health dip stems from the psychological impacts of various economic downturns and the COVID-19 pandemic. Lockdowns in 2020 also led to social isolation during formative years of their lives, and obsessive tech habits can push people further into chronic loneliness. 

“I think the distance between people is greater than it ever has been before,” Harter says. “When people become more distant physically, you become more mentally distant. That’s what’s happened with younger workers.”

But managers have often missed the mark when it comes to leading their youngest employees, or have branded them as difficult to work with. But if bosses don’t understand Gen Z and millennial workers, or take the time to learn how they tick, workplace cultures will inevitably corrode and worsen young employee’s mental health. 

“They’re coming to work wanting to build an identity, be inspired, make a difference. And they’ve got a lousy boss that is just critiquing all the time, or worse, ignoring them,” he says. “That leads to the condition we call ‘actively disengaged.’ Those people have the worst wellbeing, as we’ve seen that people who are actively disengaged are more likely to have new incidents of depression.”

When left untreated, employee mental health issues can boil over and become big workplace problems. They’ve kept millions of people out of the labor force, led to higher rates of turnover, and contributed to sweeping burnout. 

Harter says the best way to foster positive well-being among young workers is to ensure that managers are good leaders: bosses who have weekly one-on-ones with staffers, provide meaningful feedback, listen to their input, and create collaborative ways to engage their teams. 

“Part of getting work right is reducing misery. Get rid of the terrible managers and make sure you increase the number of great managers over time, so people look forward to being there,” he says. “Feeling that somebody cares about me at work, that I can do what I do best, can reduce loneliness. So they should pay attention to practices that not only inspire people, but also build high productivity, higher retention rates, and customer results.”