The staff you manage are there to work. They have a job to do, you have a job to do, and there's an aim between you to complete tasks that the organisation you're all employed by needs done. But we're none of us machines, with machine minds and machine hearts. We exist separately to our work, and it's important that all workplaces, all employers recognise the role that a job plays in an individual's life, and that their life plays in how they do their job.

Why? Well, again, we're not machines. We can't switch one part of ourselves on and another off when we walk through the door, much as we may try to; if we're not able to lead a healthy and happy life in one aspect of our days, then we can't lead a healthy and happy life overall. And this will inevitably impact on the quality of work we produce - so, as a manager, it really is essential that we do what we can to help our staff to be happy and healthy.

There's much that we can do within the office. It's important not to place excessive burdens on your staff - don't overload them with work, don't give them so much to do that it eats away the time they need to relax and recover. No-one's saying that there should never be a time when the needs of the company require an employee to work beyond their standard hours, but it must always be borne in mind that everyone needs a healthy work-life balance, and that if the former is eating up too much of the latter, both mental and physical health can suffer. In cases where the job is intrinsically more stressful, it becomes even more critical to ensure that staff can get away from it.

There are also other factors that can have a substantial impact upon the staff, such as the atmosphere within the office, and a sense of being involved, of understanding managers and their aims. But however considerate and pleasant the working environment, there may still be cases where employees feel unable to cope, and a successful manager will need to have strategies to deal with these issues as and when they arise. A study by Mind in 2010 reported that 70 million working days are lost in the UK every year due to mental health issues, primarily stress and depression; that employees leaving their jobs due to mental health issues costs UK businesses £2.4 billion each year; and that those who remain in work but without support cost £15.1 billion in lost productivity. It's not hard to see why it's essential for your business to be able to support staff suffering from such conditions.

It's important to have an understanding of what stress and depression actually mean, as a good deal of misunderstanding exists. Stress first: it's not simply a matter of feeling browbeaten and overwhelmed, not just something that affects those whose daily life is a struggle (although such conditions certainly can cause an enormous amount of stress). Rather, it's a physical reaction, the body producing a range of hormones - including adrenaline - in order to give us a boost of energy when we need it most. In nature, this is the 'fight or flight' response, allowing an escape from a dangerous situation, but our bodies are conditioned to reproduce that response whenever we need it. And it can be a good thing, certainly, giving us the energy to meet a crucial deadline or succeed in a difficult negotiation. However, over time the accumulated impact of stress can create a genuine and harmful strain, on our bodies and on our brains.

Depression, it's essential to understand, is not simply feeling sad. It's an illness, and one that can be highly debilitating. There are many potential causes - amongst which, it can often be caused or exacerbated by stress - and a wide variety of treatments that a GP can help the sufferer with. As a manager, the first thing you need is understanding; there's long been a tendency to expect those with depressive illnesses just to 'suck it up' or 'pull themselves together', but that's neither possible nor a fair response, any more than it is for an employee with a physical disease. You should always be prepared to listen, and to offer support and encouragement; your staff should never feel afraid to discuss any problems they are having with you, and you should be ready to take an interest if you're concerned about changes in anyone's behaviour. Remember, it's a big step for anyone to admit that they have mental health issues, and it's critical that they feel supported, not dismissed - if they have support in their working life, they're considerably more likely to feel confident enough to seek professional assistance, which in turn will help your business by reducing those costs and lost days.

There may be times, however, when individuals find that they can't cope with their regular job. Again, as a manager you need to be sympathetic. Of course, if they need time off it's important that they don't feel that they're causing a problem for the company in doing so. But is time off always necessary? If the individual is in a pressurised job, are there other duties they can do instead, which will help them to recover while still remaining productive (which is good for their morale, and good for the business)? Could you consider more flexible working hours for a period? In providing a way for your employee to get better without feeling shunned or isolated, you'll be helping them to recover, and to continue as an effective and needed member of your team.

All this can be difficult, particularly at first and if you've no experience of managing mental health issues at work. But don't worry; making an effort, being sympathetic and simply applying common sense is at the heart of everything, and we can all do that. You might also want to consider a short management training course, to help develop strategies for whatever issues may arise at work. After all, the organisation relies on its staff; helping them to be as healthy and happy as can be can only benefit the company as a whole.