Autism 'may have quadrupled'

The cases of autism are thought to be increasing

The number of cases of autism could be four times higher than previously reckoned, warn scientists.

A study by researchers from the Central Clinic, Stafford, and King's College, London, looked at 15,000 children aged between two and six.

Earlier studies estimated the prevalence of autism at between four to six cases per 10,000, but the latest study on children in Staffordshire showed the rate to be nearer 17 cases per 10,000.

Even autism experts who suspected that existing studies had produced overly conservative results said that the latest findings were unexpectedly high.

Most people will agree that there has been an increase

David Potter, National Autistic Society

Autism is a developmental disability that affects the way a person communicates and interacts with other people.

Many people with autism cannot relate to others in a meaningful way and may also have trouble making sense of the world at large.

The study also found that "pervasive developmental disorders" which fall short of the strict diagnostic criteria for autism were running at a rate of nearly 46 per 10,000.

Among these were Asperger syndrome, a condition in which children display autistic behaviour, but have well-developed language skills, Rett syndrome, a disorder in which skills that have been acquired, such as walking and talking, gradually disappear; and childhood disintegrative disorder, a rare condition involving severe deterioration of mental and social functioning.

The report, published in the Journal of the American Medical Association (JAMA), conceded that methodological limitations in the study prevented a conclusion that the disorders looked at are actually on the increase but it said that possibility required "further rigorous testing."

No central data base

David Potter, a spokesman for the National Autistic Society, said it was difficult to record autism figures as there was no central data base.

But he said it was a widely held view that cases were on the increase and that this could be due to better diagnosis.

"Most people will agree that there has been an increase. We thought there were about 10 cases per 10,000.

"If the figures in this study show the new levels then there will be significant ramifications for local authorities when it comes to planning for people with autism."

Those figures will assist in planning for services that affected children and their families will need

Susan Hyman
University of Rochester

In an editorial in JAMA commenting on the study, Susan Hyman, a physician with the University of Rochester School of Medicine and Dentistry in Rochester, New York, said the findings highlighted the need for improving the early detection of affected children.

"There is increasing evidence that behavioural and educational intervention with young children may significantly improve developmental and behavioural outcomes and that basic deficits in play and communication may be therapeutically modified.

"Those figures will assist in planning for services that affected children and their families will need."