By Jeremy Laurance
London - Almost twice as many children may be affected by autism as had previously been thought, researchers say.
A survey conducted in 12 districts in south London suggests one percent of children in Britain - about 100 000 - are affected by the lifelong developmental disability that impairs the way people communicate with each other.
If confirmed, the finding will have big implications for health, education and social services. Previous estimates by the Medical Research Council suggested 60 000 children were affected. Prior to the 1990s, researchers estimated fewer than 5 000 cases.
The study was carried out by doctors from Guy's and St Thomas' hospitals. Writing in The Lancet, Professor Gillian Baird and colleagues said: "The consensus diagnosis of autism and in particular other autistic spectrum disorder cases could be associated with the broadening of diagnostic criteria over time, which might be responsible for the rise in reported prevalence, but other explanations cannot be ruled out."
The National Autistic Society said: "This research underlines the importance of appropriate services for individuals with autism. Current provision is deeply inadequate given the scale of the need."
A personal story
Sandra Dewar spent five years coping with criticism from teachers and parents over the behaviour of her son, Stewart, before he was finally diagnosed with Asperger's syndrome, a mild form of autism.
Now 13, Stewart is doing well academically, but "if he had been diagnosed before he started school, we would have been spared all that harassment," she said.
"There are programmes that can help children like Stewart but the earlier they start the better. When everyone is against you it is hellish."