Over two-thirds (69%) of employees who've experienced a mental health condition worry they'll be judged at work because of that condition, research has found.
The poll from AXA PPP healthcare of 2,000 employers also found 73% who'd had a mental health condition such as stress, anxiety or depression said they didn't feel comfortable speaking with people at work about it.
Fewer than half (46%) said that they felt their employer had given them adequate support.
In addition, 1 in 4 employees (24%) working in larger organisations (250+ employees) had been diagnosed with a mental health condition compared with 19% working in smaller sized firms.
Meanwhile 27% of women surveyed said they had been diagnosed with a mental health condition compared with 19% of men.
And 70% of those who had experienced a mental health problem said they didn't like people at work to know about it.
Dr Mark Winwood, director of psychological services at AXA PPP healthcare said: "It's concerning that nearly two thirds of the people we surveyed who said they'd had a mental health problem also indicated they were worried they'd be judged for it at work.
"Stress, anxiety and depression are relatively common but people who experience them are reluctant to open up to others as they fear discrimination, alienation and being stigmatised.
"In the workplace, mental health conditions can be the elephant in the room. By recognising this and positively encouraging open conversations about mental health, employers can take a big step in helping employees who are trying to deal with psychological problems and reduce the associated stigma."