Autism diagnoses jump 20 per cent

The likelihood of a child’s being given a diagnosis of autism, Asperger’s syndrome or a related disorder increased more than 20 per cent from 2006 to 2008, according to a report released Thursday by the Centres for Disease Control and Prevention.

The new report estimates that in 2008 one child in 88 received one of these diagnoses, known as autism spectrum disorders, by age 8, compared with about 1 in 110 two years earlier. The estimated rate in 2002 was about 1 in 155.

The frequency of autism spectrum diagnoses has been increasing for decades, but researchers cannot agree on whether the trend is a result of heightened awareness, an expanding definition of the spectrum, an actual increase in incidence or some combination of those factors. Children “on the spectrum” vary widely in their abilities and symptoms, from mute and in- tellectually limited at one extreme to socially awkward at the other.

Doctors working to update the Diagnostic and Statistical Manual of Mental Disorders have proposed significant changes to the definition of autism, due to take effect in 2013. If the changes are carried out, some experts say, they could reduce the number of children being given a diagnosis.

“One thing the data tell us with certainty: There are many children and families who need help,” Dr. Thomas R. Frieden, director of the CDC, said in a news conference Thursday.

The CDC team’s findings were based on evaluations of the children, drawn from 14 states. The estimated rates in those states varied widely, from 1 in 210 children in Alabama to 1 in 47 in Utah.

Overall, boys were almost five times as likely as girls to get such a diagnosis – at a rate of 1 in 54, compared with 1 in 252 for girls. The sharpest increases appeared among Hispanic and black children.