A recent study has received a lot of media attention over its finding that clinical diagnoses of autism spectrum disorders (ASD) may be inconsistent across assessment centers. Current diagnostic criteria for ASD is broken down into three separate diagnoses, which include autistic disorder, pervasive developmental disorder-not otherwise specified (PDD-NOS), and Asperger’s disorder. In this study, the authors set out to determine if clinical diagnoses of these disorders are consistent across different assessment centers.
Participants included 2,102 children and adolescents with ASD, ages 4 to 18 years. Each participant received a diagnostic evaluation at one of 12 university assessment centers across the nation. Diagnostic evaluations included the administration of the Autism Diagnostic Observation Schedule (ADOS), as well as other standardized diagnostic, cognitive, and behavioral instruments. Using the test scores and clinical judgment, clinicians at each center were instructed to give the participants a diagnosis of autistic disorder, PDD-NOS, or Asperger’s disorder. The consistency of clinical diagnoses across assessment centers were determined based on both the participants’ test scores and their final diagnoses.
The results indicated that the participants’ test scores were similar across assessment centers; however, significant differences were found in regards to their clinical diagnoses. This suggests that clinical judgment, not psychological test scores, accounted for the inconsistencies seen in clinical diagnoses.
The findings of this study reveal that clinical diagnoses of ASD may not be consistent across assessment centers. The authors offer several possible explanations for their findings. For starters, clinicians in some areas may be more inclined to give diagnoses of autistic disorder as there may be more services available for autistic disorder as compared to other ASD diagnoses. In other areas, clinicians may avoid giving autistic disorder diagnoses due to the greater stigma associated with a more severe diagnosis. Ultimately, the authors suggest that their findings demonstrate that the current clinical definitions of autistic disorder, PDD-NOS, and Asperger’s disorder do not have distinct diagnostic boundaries, which the authors argue support the transition to a more comprehensive clinical definition of ASD.
Lord, C., Petkova, E., Hus, V., Gan, W., Lu, F., Martin, D. M.,… Risi, S. (in press). A multisite study of the clinical diagnosis of different autism spectrum disorders. Archives of General Psychiatry. doi: 10.1001/archgenpsychiatry.2011.148