Mental health-related absence is costing UK employers more than £9bn a year, according to research by the Shaw Trust charity.
One in five companies said staff who had been off work with stress, depression or some form of mental ill health for more than a few weeks were unlikely to ever recover, its survey of 550 employers showed.
Just 3% believed their company had an effective policy for dealing with stress and mental ill health in the workplace. And eight in 10 said they had no company policy at all for mental health issues.
Tim Cooper, managing director of the Shaw Trust, said mental health was the last taboo in the workplace.
“Society has confronted discrimination on the basis of age, gender, race, sexual orientation and religion, but there is a worrying lack of understanding about mental health, and it is not often openly discussed,” he said.
“There is still workplace discrimination towards people who have suffered mental ill health, although it may not be deliberate or conscious. It wastes ability, talent and skills and spoils lives.”
Mental health charity MIND estimates that a third of employees will experience stress, depression or some other form of mental ill heath at some point in their lives.