But Joe is lucky. He is about to be freed from the torment he has suffered since his 11th birthday, because he is attending an innovative new clinic at the Maudsley Hospital in south London. Here, specialist Dr Isobel Heyman and clinical psychologist Dr Ian Frampton are running a new treatment programme for young sufferers of OCD, which is thought to affect one in every 100 people .
Obsessive and compulsive behaviour such as continuous washing, checking (to see if the light is on or off, for instance) and perfectionism in work can sometimes be contained by adult sufferers, though most commonly they retreat to a life indoors, trapped by their OCD. For children, the intrusive and "bullying" thoughts which dominate their lives are almost unbearable, made more burdensome by the apparent silliness of being worried by specks of dirt or light bulbs that haven't been turned off.
Children with OCD are not "mad". They fall within the normal range of intelligence and come from a variety of backgrounds. Dr Heyman believes that the cause of their disorders is biological, and cites an American programme which used blood transfusions to cure children who developed OCD after suffering streptococ cal throat infections. What is certain is that individualised programmes using drugs to regulate the uptake of serotonin (a brain chemical), and behaviour modification to give children control of their lives, are helping patients at the Maudsley clinic.
After help from the clinic, Joe was able to go back to school and is now hoping to take his GCSEs and able to recognise the symptoms of his OCD. When he gets worried by something dirty, he has the confidence to reach out, touch and "disarm" it, even if it is his little brother's football. His parents are also able to get him out of the bathroom. Family involvement is crucial to behaviour management.
Dr Heyman's clinic relies on the interplay between research and treatment that is the hallmark of the Maudsley's approach to mental health. Whether it is conditions little known to lay people such as Fragile X, a chromosome abnormality which results in learning difficulties and "oddness" in manner and appearance (and which affects more than one in 3,000 including associated inherited chromosome impairments), or the more common affliction of juvenile delinquency, the hospital pioneers treatment.
The Maudsley's child and adolescent service is at the forefront of research and treatment development, treating 750 new patients a year from all over Britain; its child guidance clinic sees another 750, mostly from south London.
Professor Sir Michael Rutter, the world-famous child psychiatrist, is at the helm of two of the hospital's research units and its 750th anniversary appeal to build a new centre for children and young people. "It is a great chance," he says, "to bring together under one roof facilities for research and patient care and benefit the children and adolescents who need our help. "
The sprawling site on Denmark Hill is home to some of the best work in child mental health being carried out anywhere today. A rarefied biochemical study on the role of brain chemicals in hyperactivity is conducted next door to cognitive therapy sessions for depressed or suicidal children. Inherited autism can be treated with behavioural techniques; drug misuse and criminality linked to family breakdown and poor educational achievement can spring either from genetic misfortune or social adversity, or both. It can therefore be treated with a mixture of family therapy and medication.
Along the corridor from Dr Heyman's office, Dr Robert Goodman, reader in brain and behavioural medicine, has for the past 10 years been running the country's only hemiplegia clinic. He sees 40 new patients a year and has 400 on his books from all over the UK. Hemiplegia, a cerebral palsy affecting one side of the brain, leaves sufferers weak, stiff and with problems handling everyday social situations. It affects one in 1,000 children. These are children, says Dr Goodman, who are "always being told how lucky they are that they haven't got worse cerebral palsy. But that's not how it seems to them".
Hemiplegics may well have learning difficulties as well as physical disabilities; they get very anxious, and are likely to be hyperactive; they may need medication and physiotherapy; they may also have special educational needs, specifically in relating to their peers. Yet because they may have learned to adapt, their needs are often dismissed by the educational system. As Dr Goodman says: "A lot of the children I see come because school is such a bad experience for them."
Dr Goodman has appeared as an expert witness at three SEN tribunals. While he has nothing but praise for the tribunals themselves, he is uneasy with a system that forces parents to demand recognition of their child's needs from teachers who lack special training, while cutting back on educational psychologists. Children with moderate learning difficulties are often squeezed both ways, says Dr Goodman, "by having unrealistic demands made on them, or having their disability recognised but not given adequate provision". In addition, because children with learning problems often seem "good" (well behaved) at school, teachers and parents may be slow to recognise their problems.
Hemiplegics, like children with OCD or depression or phobias, may be bullied, not for their physical problems, but because their social skills are not up to those of their peers. Where the depressed or OCD child may be too preoccupied to respond properly, a child with autism or hemiplegia may have brain malfunction which means they have trouble "reading" the nuances of behaviour.
Dr Goodman and his team test what is called "theory of mind" by trying out fictional stories which require an understanding of the use of lies and ambiguities. Children with inadequate social skills will misread the following:
"Jim wants to buy a puppy. He goes with his parents to Mrs Smith's house. Her dog has just had four puppies. She is an animal lover who would never harm the dogs in her care. Jim wants a female pup but Mrs Smith only has male pups. Although they are cute, he still wants a female. But Mrs Smith says that if he does not buy one, she is going to have to drown it. The pups need a home. What should Jim do?"
Hemiplegic children will not spot the bluff (that Mrs Smith would never harm the animals), nor be able to put themselves in the shoes of another with mixed motives. They are socially "nuance-blind".
With this kind of deficiency, the help that can be received with the right SEN statement is crucial. In an ideal world, says Dr Goodman - author of controversial articles on the need to stop medicalising educational problems and concentrate instead on developing classroom solutions to social problems - educational psychologists would be assessing the educational needs of children. In the real world, highly paid and trained psychiatrists have to go to tribunals. Why, asks Dr Goodman, should it take a tribunal to allow Katie, born six hours before midnight on August 31, to repeat a year of school, given that she is not only the youngest in her year by a long way but also suffers from speech delay, physical impairment, specific learning difficulties and social problems?
Dr Goodman is involved in one strand of the Maudsley's work. Another concentrates on conduct disorder, including Attention Deficit Hyperactivity Disorder, which is estimated to affect up to 2 per cent of the population. New services, such as a 24-hour parasuicide service for adolescents, based at King's College Hospital next door, continue to be added.
For the young people who use it, the Maudsley is an unparalleled and growing resource. As Dr Brian Jacobs, clinical director of the child and adolescent service, modestly puts it: "Our work is highly significant."
For details of The Maudsley's appeal, contact: Rosina Pullman, appeal director, on 0171 919 2014