Last year I discovered a shocking statistic about the state of mental health in the UK. In the 1960s the average age for the initial onset of depression was 45. It’s now 14. The scale of mental health problems among young people has been much commented on in the media but this statistic really brought it home.

It‘s consistent with a wider trend that has seen mental health problems among young people soar.  There are rising levels of body dissatisfaction among young women, with around half of 15-year-old girls and a quarter of boys in England and Scotland believing themselves to be too fat.

Meanwhile, among young women there has been a 68% increase in hospital admissions for self-harming over the last decade.

One can’t help speculating on the role of social media, with its relentless capacity for peer comparison and criticism, in fuelling this rise.

The causes are likely to be more complex but what is clear is that the NHS is struggling to cope. And that means as young people enter the world of employment, businesses are going to find more mental health issues playing out in the workplace.

Common psychological problems like stress anxiety and depression already account for the largest proportion of sickness absence among employees. Significantly these conditions also represent the commonest cause of long-term sickness absence. So employers have reason to be concerned.

To be fair lots of them already treat mental health in the workplace as a strategic priority. A large number of organisations have now signed up to the Time to Change pledge, which commits them to tackling the stigma of mental ill health at work. Indeed many have gone beyond that with comprehensive wellbeing programmes in place to support the psychological health of employees and to help those that are well, to remain so.

Whilst this represents real progress, something vital is missing and without it we’ll never change the culture around mental health in the workplace.  To do that employers need to equip line managers with the ability to engage sensitively with employees who disclose they have a problem.

That means training for line managers that will enable them to understand and recognise the signs of common mental health problems and give them the skills and the confidence to provide the right kind of support when it’s needed.

But most employers are a long way from achieving that. A recent BITC survey found that only 24% of line managers had received the kind of training that would make a difference. Yet the need is clearly there and managers have the appetite for it. A year or so ago I attended an impressive mental health event held by one large UK employer. It included some great examples of best practice and the session was hosted by a senior manager who was championing the mental health agenda.

But when it came to Q&As an employee put their hand up and said - ”Look - I’m a manager and I’ve had a couple of situations in which I felt a member of my team had mental health issues but I didn’t say anything. And I didn’t say anything because I was scared that if I did, it might be the wrong thing and I might end up making the situation worse …so I said nothing and to this day I feel terrible about it.  I feel I let them down. What are you supposed to say?”

Now I’m convinced there are managers like this in almost every business...

They’re not uncaring people, indifferent to the welfare of their people. On the contrary, they want to say and do the right thing but they’re not sure how and that’s why this kind of training is so important.

This crucial gap in provision was one of the reasons Bank Workers Charity (BWC) in partnership with Mind, developed a mental health training programme for line managers that ran as a pilot in some of the UK’s biggest banks.  Its success was confirmed not just by line managers, whose confidence in tackling mental health issues soared but by their subordinates who, after their managers had completed the training, found their workplace a less stressful place to be.

This vindicated our decision to develop the programme and I remain convinced that skills based training is the way forward. But as we’ve seen, line managers in most companies are not so well served and, in the absence of effective training, are having to wing it when faced with workplace mental health issues.

Whilst some, notably those who are natural communicators with strong people skills, respond with the required sensitivity, there must be thousands of situations where the managers do their best but get it wrong.

Only 24% of line managers had received the kind of training that would make a difference.

At BWC we’ve made workplace mental health a priority issue, so I have followed with interest the different approaches companies have taken to offering mental health training.

Over the last five years there has been a significant increase in the number of organisations providing training to their people, which is encouraging, but a note of caution is needed. Firstly, much of it has been awareness raising rather than skills development.

Secondly and importantly, much of it doesn’t target the people for whom it could make the biggest difference - the line managers. That needs to change and I think it will, if only because the increased prevalence of mental health issues in the workplace will force it up the business agenda.

As corporations continue to focus on mental health and with influential bodies like Business in the Community and Mental Health Foundation publically calling for mental health training for line managers, I fully expect it to become the norm in the years ahead.