Diagnoses of Autism Spectrum Disorders Vary Widely Across Clinics

To diagnose autism spectrum disorders, clinicians typically use a variety of tests and scales, as well as interviews with patients and families. They then classify individuals into subcategories listed in standard psychiatric diagnostic manuals. A study, published online on November 7, 2011, in Archives of General Psychiatry, found that these diagnoses vary widely across centers and that simply reporting the results of diagnostic tests and scales, along with other tests such as IQ and language measures, would more accurately determine who has autism and is likely to continue to have it over time.

Catherine Lord, PhD, and colleagues at the Institute for Brain Development, a partnership of NewYork-Presbyterian Hospital, Columbia University Medical Center, and Weill Cornell Medical College, studied approximately 2,100 people between the ages of 4 and 18 who had been diagnosed with autism spectrum disorder at one of 12 university-based centers. They found that diagnoses of specific categories of autism spectrum disorder varied dramatically across the sites. For example, the percentage of individuals diagnosed with Asperger syndrome ranged from zero to nearly 21 percent. In the future, Dr. Lord plans to work on making diagnostic instruments shorter, easier to use, and appropriate for a broader range of patients.