Over a third of employees describe mental health issues as a "taboo" subject and over half believe physical illness will always carry less stigma than mental health problems, according to research by Aviva.
Encouragingly the survey found over a quarter of UK employees believed the stigma associated with mental health issues in the workplace was decreasing.
Better understanding of mental health by peers and colleagues was the most common cause suggested while over a third also highlighted the impact of TV and press campaigns.
Celebrities talking openly about mental health issues and government policies were also mentioned by roughly a quarter of respondents.
Depression Alliance chief executive Emer O'Neill said: "The stigma has been decreasing year on year and that is backed by evidence and high profile people speaking in the papers, celebrities as well as business people.
"We are making a dent in the right direction. But we are nowhere near the level we should be. The majority of people are still frightened to talk openly about their condition especially in the current climate as people are nervous about their jobs."
The research also found a growth in awareness at the top - the most popular health initiative employers mentioned they would like to implement was support on mental health issues.
Moderate depression was the most common of psychiatric conditions, according to Aviva claims data, followed by anxiety and stress.