Where a child is tested could affect autism diagnosis, study finds

A recent study supports a growing number of autism experts who wish to diagnose those who meet certain criteria as having autism spectrum disorder. This would end any distinction between subtypes of autism such as Asperger syndrome and pervasive developmental disorder-not otherwise specified (PDD-NOS).

Researchers found autism centers across the country have inconsistent criteria that health professionals use to determine a child’s diagnosis, meaning where a child is diagnosed plays a role in which diagnosis that child receives. Different sites appear to have been using its own criteria for autism versus Asperger and PDD-NOS, leading to many variances when assessing children with milder problems.

Researchers for this study collected data on 2,100 children from age four to 18 who met the criteria for an autism spectrum disorder. Twelve university-based autism centers in the United States provided the data. The children in the study had previously been subject to routine tests, measuring language, thinking and communication skills and behavior. Children were then diagnosed by a psychologist, psychiatrist or other health professional.

At one site, health professionals diagnosed children with an IQ of more than 70 with having Asperger syndrome. At another site, children were only diagnosed with Asperger if their IQ was more than 115, according to lead study author Catherine Lord, director of the Institute for Brain Development at Weill Cornell Medical College and New York-Presbyterian Hospital.

Researchers found large inconsistencies in whether the 39 percent of children with milder problems in the study were labeled with autism, Asperger or PDD-NOS.

The 61 percent of children with classic signs of autism such as severe language problems, communications and social deficits, and repetitive behavior had good consistency among the centers, said a report in the Nov. 7 online issue of Archives of General Psychiatry.

Lord said, “The second most important predictor of which diagnoses the clinician made was where they worked, not any characteristic of the child, which is not good.”

Lord explained that children with significant impairments in language, communications and social skills, who show repetitive behaviors, and who have intellectual disabilities are generally diagnosed with autism. Those children who have some of the characteristics of autism, such as language delays and social problems, but whose characteristic are subtle or not obvious behaviors, can be diagnosed with PDD-NOS. And children who have some characteristics of autism as well but who have good verbal skills, are very intelligent, or have less obvious social impairments, are said to likely have Asperger syndrome.

Whether a child is diagnosed with Asperger or autism does not affect the resulting treatment, but there are many reasons for the inconsistencies in the diagnoses. In some areas, children can only receive certain services if they have autism. There are also personal reasons.

Lord noted that health professionals may be influenced by a parent’s wish to hear their child has Asperger rather than autism.