The front room of the Darwin family's house in Barnet, north London, is full of the paraphernalia of domestic life. Books line the walls, jostling for space with wedding photographs, a television and computer workstation. In the middle, a large bouncy castle is occupied by three attractive, lively, children, Miranda, five, Owen, seven, and Camilla, 10. Their parents Andrea and David explain that they have to have the castle for Owen.
On the wall, one of Owen's drawings shows a fairground with a bouncy castle. In breaks from bouncing, he is making a book entitled The Teletubbies and their Bouncy Castle. David says, "If we go to a fete where there's a bouncy castle, Owen makes us stay until it's packed away. We go on holiday to the same place every year because there's a bouncy castle."
Andrea says Owen often gets obsessed with things he likes. It's all part of his autism, diagnosed last year. Andrea explains how her experience with her eldest daughter Gemma, now 12, left her sensitive to Owen's difficulties. "Gem's problems at school started when she was five. I knew she was bright but the teachers said she was slow. She was struggling, and got a statement of special educational needs, but we still didn't know what was really wrong."
For five years, Andrea and Gemma ricocheted around local health and education services. By then, Andrea says, "Gemma wanted to be dead. The strain of school was awful and we were begging for a proper assessment".
Andrea hadn't considered autism until a neighbour, hearing Gemma's tantrums, suggested it. Andrea contacted the National Autistic Society which said that Gemma's flapping, spinning and other behaviour was typical of the condition. They suggested that David Skuse, professor of brain and behavioural sciences at the Institute of Child Health, could help.
Gemma's GP referred her to Skuse's clinic at Great Ormond Street Children's Hospital. Within two months she was diagnosed with Asperger's syndrome, a form of "high-functioning" autism.
After her experience with Gemma, when Owen's teacher mentioned autism, Andrea swung into action. "The GP suggested our local psychiatric service, but I said, 'No, I've not got five years to wait like with Gem.'" She wrote to Skuse and within weeks Rebecca Chilvers, his roving clinic psychologist, had assessed Owen at home.
Chilvers has seen children aged from two to 16 in 80 families across Britain, cutting waiting times for new appointments from five months to just two weeks.
As she explains: "A few other clinics see children with high-functioning autism, but none offer a pre-clinic home visit and follow-up assessment at school. High-functioning autism can be very hard to spot. It's often mistaken for conduct disorder because affected children get intensely frustrated and no one asks why."
Chilvers' home visit involves filming the child doing a structured autism assessment and an IQ test. Within about four weeks families see Skuse, whose computerised system asks parents 140 questions about their child's strengths and difficulties in a standardised, quickly analysed way. He usually makes the diagnosis the same day.
Skuse says that many parents ask, "How autistic is my child?" and that the computer programme allows him to answer. "I assess children who have autism but also those who are developmentally normal or have other problems. I can tell parents quite accurately where their child is on the autism spectrum and offer clues about their future."
Many children such as Gemma and Owen have autistic problems which are sufficiently subtle to be missed or mistaken for something else, and Skuse too is looking to the future.
He believes that those working in local mental health services must be better trained to detect autism. Later this year, a new member of staff joins the Institute of Child Health dedicated to doing just this. Skuse says "We haven't advertised the course yet, but about 80 paediatricians, psychiatrists and clinical psychologists have already signed up. We hope to train 150 annually, enabling them to spot high-functioning autistic children younger and identify the help that can revolutionise lives"
But Skuse is not optimistic that children always get access to the necessary care and support. "We have a psychologist who offers a short course in survival social skills, and children benefit enormously. But we can't provide continuing care for all those we see, and they need to be confident in local education and health services."
Andrea says that these dismally failed her children. Chilvers agrees that getting appropriate support in school is often difficult. "Not all education authorities give children statements of special education needs, so it's hard to see how some will be helped." Her comment reflects last year's audit commission findings that children are often let down by patchy, inefficient services.
Back in the crowded bouncy castle room, it's difficult to imagine that it feels as if something's missing. But it does. It's Gemma. Owen and his sisters talk about her a lot. Gemma has spent the past five months in a psychiatric unit, with obsessive compulsive disorder. Andrea says she's sure that this is a result of the years of trauma before Asperger's syndrome was recognised. "How many 12-year-olds do you know in mental hospital? It was fight, fight, fight all the way to a diagnosis."
Skuse agrees that Gemma's current problems are probably distinct from her autistic disorder, saying that "co-morbidity" - conditions existing alongside autism - is not uncommon.
Andrea is worried that Owen may go down the same route as Gemma. "He was diagnosed quickly, but that's no good if he can't get the support he needs."
It's easy to forget that Owen needs help. He burrows his head deep into the sofa before dashing back to bounce, and Andrea looks tired. She's only missed the trek into central London to see Gemma twice in five months. Andrea and her husband want to put the bouncy castle in the garden when the weather gets better. With any luck, Gemma will be home to enjoy it.
Autism: some facts
· Autism is a lifelong disability affecting the way people communicate with, relate to and understand others. Severity varies, leading to the concept of "autistic spectrum disorders" (ASDs).
· About six in 1,000 people have an ASD. It affects three times as many boys as girls. Recent increases in diagnosis follow greater awareness of and changed ideas about ASDs.
· Autism's "triad of impairments" are in social interaction, communication and imagination; repetitive behaviour, resistance to change and learning disabilities may occur.
· Those with "high-functioning" autism or Asperger's syndrome rarely have learning disabilities and are of average intelligence or above
· 70% of autism cases may be high-functioning or Asperger's. The same person may be diagnosed with both at different times and the distinction between them is possibly insignificant.
· Autism/ASDs are not inherited simply, like eye colour, but genes seem to play major roles. Environment may modify or trigger the condition but no specific risk factor has been proven to do so.
· Recent research suggests that autism may be a combination of two distinct conditions with distinct genetic bases.