Mental health problems cost employers in the UK £30 billion a year through lost production, recruitment and absence - so why aren't we doing more about it?
The answer is straightforward. Despite the fact that it is very common - one in four of us will suffer mental health problems during our lives - we find it very difficult to talk about.
It often seems too personal, too deep and too complex. You might feel very happy to tell a colleague about a physical injury you've sustained, but when it comes to your mental health, where do you start?
If you can't talk about it, it may prove equally difficult to listen.
Not listening could prove very costly - to the individual and to your business. The Centre for Mental Health charity estimate that employers should be able to cut the cost of mental health - in lost production and replacing staff - by about a third by improving their management of mental health at work.