Research from MHFA England found 18 to 24-year-olds were nearly eight times more likely to report poor mental health because of work.
More than one in four said they didn’t feel safe enough to speak up or ask for help, and almost one in three (31%) had considered leaving their job as a result.
Among younger workers, 78% said a lack of psychological safety reduced their motivation, compared with 50% of older colleagues.
Nearly a third (29%) had avoided giving honest feedback to their manager, more than twice the rate among older staff.
Sarah McIntosh, CEO of MHFA England and the Association of Mental Health First Aiders, said: “Young people don’t just need a route into work, they need workplaces that feel safe once they get there.
“When people cannot ask for help, speak honestly, or manage stress openly, employers lose the fresh thinking that early-career talent brings.
“We simply cannot afford to lose more young people from the workplace.”
McIntosh added: “This Mental Health Awareness Week is about action, and that action should start from a young employee’s very first day.”