I have been working with rough sleepers and the homeless for over ten years now, and yet still when I am asked: "Why are people sleeping on the streets?" I am unable to come up with a simple answer or a clear cause. In our modern, affluent and sophisticated society it seems anathema that something so tragic should continue to be a problem, yet it clearly is. Despite recent government initiatives such as the work of the Rough Sleepers Unit, a special national task force to deal with the issue, led by the homelessness czar, the problem is not on the decline. Why is this?

Well, the most obvious issue is the lack of affordable housing stock in this country.

With the introduction of the 'Right to Buy' policy, council housing stocks were decimated, and it is now a rare council that does not have a long waiting list for reasonable accommodation. However, this issue masks the seriousness and complexity of the problem. The truth is that by the time someone ends up on the street, they usually have a multitude of other problems.

Research consistently shows that the people who end up sleeping rough are often some of the most vulnerable in our society. Most of us have a safety net of friends, family, or work to fall back on when times are difficult. However, for some people this safety net is not so easily available. Approximately one quarter of all the people who end up on the street come from care, and so often lack any sense of stability or support in their early lives. Others, often women, are fleeing difficult domestic situations or violent families. A significant minority of rough sleepers are men who have left the armed forces, and have been unable to re-integrate with the rest of society. Also there are a large number of homeless people who have mental health issues that isolate them from help and support, particularly since the closing down of many mental hospitals in the 1980's. Many of these people suffer appallingly on the streets. One man I worked with, a former physics professor, was so paranoid and frightened by rough sleeping that he glued all the rings he could find to his fingers to protect himself from 'evil forces'. His hands became infected and swelled up - he had to have the rings and several fingers surgically removed, and almost died. Often these kinds of serious mental health issues go undiagnosed or untreated for years, and being homeless does not improve your mental health. All these reasons, and many more, indicate that often by the time that someone comes to have nowhere to live, they can already have many other problems.

Additionally there is the issue of drugs and alcohol. Often, if a person didn't have a substance misuse problem before coming to the streets they often develop it while there. When I worked in street outreach, the rule of thumb was to try to catch people new to the streets within three weeks, otherwise by then the difficulties of being street homeless would have created new problems for them. Alcohol and drug addiction is rife among homeless people - alcohol particularly is so cheap and easily available. It acts as a buffer to the loneliness, misery and the sheer cold of street sleeping. If most people found themselves standing out in the cold and rain, with nowhere to go night after night, I think that they maybe tempted to have a drink or a smoke. However, this can often lead to problems with addictions or worse. Unfortunately, as has been repeatedly proved, substance misuse like this has been shown to have disastrous and damaging long-term effects for the individuals involved.

The problem with dealing with this situation for professionals like me is the multitude of different issues that have to be tackled in each individual case. It's never as simple as finding someone a hostel to stay in, some of which provide excellent accommodation and support for rough sleepers. For example, a recent distinction to be discussed is that of dual diagnosis - which is essentially someone with mental health problems who also uses drugs and /or alcohol. As can be imagined in these cases, it can be extremely difficult to get to the root cause of what the problem is. It certainly needs more than a warm bed and a cup of tea, life saving as these things sometimes are.

And it is in this area that other projects can prove a very valuable source of support. Perhaps the most debilitating aspect of being homeless is the shame, the loss of self-respect and self-confidence. Creative projects can provide this much needed input through developing opportunities for people to express their issues in new and different ways. They give people an opportunity to gain back some of that lost self-respect and take part in activities that may have been denied to them in the past. In a large day centre I worked in, the art group was extremely popular and regularly put on exhibitions. In another a group called Street Opera came in and encouraged clients to perform, which culminated in a big show in Westminster Abbey, in front of an illustrious audience. The rough sleepers involved got a huge boost out of this, and still talk of it today when I see them.

The secret about these events is that for most of the homeless people involved it can be a huge achievement just showing up. In a lifestyle so chaotic and vulnerable, just keeping an appointment can be a major event. When people have so many complex pressures on them they rarely act predictably or rationally. However, that's what makes this kind of work so important, as building self respect and self-confidence is vital in empowering people to make different choices in their life, no matter how many practical measures are put in place by workers like me. For most of us, we never know exactly how or when we touch other's lives or make them think about things - but then this seems to me to be what art is all about.