I can't remember when I started to pull out my hair. I remember certain episodes, stills that are framed in my mind: a young girl sitting at her desk in a Portakabin classroom at Christmas time. She is having trouble with an exam question and her mind wanders. When she finally looks back down she finds the paper covered in long, mousey-brown individual hairs, stuck to the page by their wet roots. Unable to blow the hairs away from the paper, she pulls each individually from the page and hopes no one notices.

Another: coming home from school, Mum's horrified look when she discovers the almost perfect circular bald patch that had appeared on the crown of my head. The talk of ringworm and quickly being taken to see a tricholigist. When he asked me if I had been pulling out my hair I don't know how I reacted. I knew I had been pulling out my hair, but I had somehow managed to remove the normal, never-had-any-problems-girl from the 11-year-old who had started to rip out her hair one at a time so that she now had a bald patch. What I do remember, and it would come back on many occasions to mock me, were the words of my mother: "Oh what a relief - I thought it could have been something serious. We will be able to sort this out in no time, won't we darling?"

I am now 25 and almost totally bald. For the past 15 years I have suffered the humiliating ignominy of being sent back to school with scarves instead of hair, cheap pudding bowl type wigs that scratched and bothered, scared of the wind, scared of swimming pools, scared of boys. For the rest of my school career I retreated into myself. I recently heard an old school friend describing me as "painfully shy at school" and it is not an unfair comment.

No one really knew how to help. It was a problem rarely come across and although compared to other OCDs (obsessive compulsive disorders) hair-pulling somehow seemed foreign.

During my school years I was paraded in front of all sorts of child psychologists, psychiatrists, hypnotists, acupuncturists and doctors who fed me large amounts of Prozac, all determined to stop my bizarre behaviour. My parents were desperate to help but were unsure where to start. I remember sitting in front of one such child psychologist who specialised in bulimia and thinking, why am I here? I don't want to make myself sick and I am sure a bulimic doesn't want to tear her hair out. We don't share the same desires so why should we share the same treatment? There were the the constant references to my childhood - the searching for a single event or problem that might explain my strange behaviour. It was as if they needed to tick a box before they could move on. Homesickness and a dislike of boarding school were simply not good enough.

No one specialised in trichotillomania (the medical word given to hair-pulling), which added to the feeling of isolation. I did not have one of the more fashionable teenage problems such as anorexia or bulimia for which there were hundreds of Harley Street doctors, all trained to deal with precisely your problem. I am not saying that what I had was worse, because it wasn't - for a start it didn't threaten my life - but not knowing a single other person with the same problem increased the mental sense of being an outsider. I was unable to explain my motives and the craving that lay behind my addiction. Anorexia and bulimia are fuelled, initially, by a desire to make oneself more attractive by losing weight. What I was doing, and I suppose still am, is the opposite; a woman without hair is hardly attractive.

I call it an addiction because that is what I believe it is. When I am tense and need to pull out my hair I try to keep my mind on other things, try to ignore it, pushing the urge to pull to the back of my mind. But the need is too great and merely increases, my whole body tightens like screws until I crack. There is an instant feeling of relief followed by self-disgust.

While at university I decided to shave off what was left of my hair in the hope that it would deter me from pulling but this was not so. I found that even with a shaved head, after a day or two of not shaving, my hair would again be long enough to pull out with tweezers. If I had lost my tweezers I would resort to driving to all-night chemists in order to buy some more and satisfy my craving. Slowly it was not only my hair that I attacked but also my eyebrows that became victim to my craving.

Thanks to numerous realistic wigs, colourful scarves and wonderfully understanding friends, I have managed to limit the extent to which I allow my hair (or lack of it) to affect my life. But I do want to stop and when I think of the future it scares me. I don't want my children to have to explain to inquisitive friends why their mother doesn't have hair. I don't always want to worry when it's windy, feel embarrassed when the subject of hair is brought up by colleagues at work, explain to concerned strangers that, no, I don't have cancer but that I pull my hair out and watch as their expression changes.

However many times I am reassured by friends and family that my lack of hair doesn't matter I know that in the long run they, particularly my boyfriend, want me to stop and look forward to when I have my own hair instead of an assortment of wigs and scarves. They see this period of my life as being only temporary and are waiting for me to move on. I, on the other hand, can't remember a time when I had a full head of hair. There have been brief interludes over the past 15 years when I have stopped for a couple of months, my hair grows back and I have felt relatively normal again. Then something triggers the impulse to pull and as soon as that first hair comes out the rest follow in a frenzy, an almost mad sense to totally rid my head of hair followed by pangs of guilt and lack of self-worth. Pulling my hair out is what I know, so intrinsically part of me that I can hardly imagine what it would be like to be free of the desire to tear individual hairs from my head.

I know there are a few organisations that do try and help people who pull out their hair. I have tried to contact one or two but found my letters unanswered. Perhaps the lack of patients precipitates closure. Despite statistics that show that 2% to 4% of people in the US pull out their hair, the causes and treatment of trichotillomania have not yet been thoroughly addressed. Unsurprisingly, although numerous support groups and websites have sprung up in the US, in the UK the number of people that understand the true nature of the problem - and are able to offer help and advice - are few and far between.

I hope that one day when a young girl finds her exam papers covered in her own hair she will be able to get help, to talk to someone who really understands what she is doing and may just be able to halt the craving before it goes on to affect the rest of her life.