According to the mental health charity Mind, one-quarter of staff are likely to have a mental health problem at some point in their career.
This means employers need to be in a position to support workers experiencing such problems in order to keep them in employment.
Spokesperson Alison Kerry said: "There is a lot employers can do to identify if their staff are having problems, it is very much about helping people at an early stage."
And she said flexible working hours and arrangements, as well as counselling services, can help to prevent mental ill health and aid the recovery of sufferers.
According to figures compiled by the Office for National Statistics in 2006, one in six adults suffers from a neurotic disorder such as anxiety or depression.
