Ongoing concerns about the utility and reliability of diagnostic distinctions between specific autism spectrum disorders (e.g., Autistic Disorder, Asperger’s Disorder, Pervasive Developmental Disorder: NOS) have led to proposals for reform in the upcoming revision of the Diagnostic and Statistical Manual (DSM-V). Under the current proposal, the DSM-V will offer only one diagnosis, “Autism Spectrum Disorder” (ASD), rather than the five diagnoses currently falling under the umbrella of Pervasive Developmental Disorders. However, some clinicians and researchers have raised concerns about the proposed DSM-V diagnostic criteria. Retrospective reviews of existing data sets suggest that the DSM-V may not be as sensitive as DSM-IV, particularly for individuals with IQs in the average range or above.
Objectives:
The goal of this study was to better understand the distinctions between DSM-IV and DSM-V criteria, and to determine whether there are specific features that distinguish individuals who differentially meet criteria across the two versions of the Diagnostic and Statistical Manual.
Methods:
Data are currently being collected from individuals presenting for psychological evaluation at a clinical center specializing in assessment and treatment of ASD’s. The comprehensive psychological evaluation includes developmental history, cognitive/ developmental testing, diagnostic assessment, and adaptive assessment. Licensed psychologists complete the evaluations and most patients are seen by two psychologists. Following assessment, the psychologist(s) complete a rating form indicating which of the specific symptoms of ASD the individual meets under DSM-IV criteria and a separate form indicating the specific symptoms met under DSM-V criteria.
Results:
Based on the number of patients currently scheduled for assessment, we expect our subject pool to reach 100 by the end of April, with a range of cognitive functioning. Preliminary results indicate that among the 22 children who met DSM-IV criteria for ASD, three did not meet criteria for diagnosis under DSM-V. All children who met criteria under DSM-V also met under DSM-IV. A multilevel item response model was conducted to explore sources of variability contributing to the discrepancy between criteria in DSM-IV and DSM-V. Current results suggest that DSM-V criteria are met as the severity of symptoms increases, i.e., higher functioning individuals are less likely to meet criteria for diagnosis on DSM-V. Further, individuals exhibiting more heterogeneous patterns of behavior are less likely to meet diagnostic criteria under DSM-V. Ongoing analyses will extend this model with predictive power from the Vineland Adaptive Behavior Scales, ADOS classification and IQ.
Conclusions:
Current results replicate findings that the proposed DSM-V criteria for ASD have reduced sensitivity for higher functioning individuals diagnosed with ASD according to DSM-IV. Our pending results represent the first field trial of the proposed criteria in a clinic sample and suggest that the DSM-V will have a significant impact on ASD diagnosis. This has the potential to affect access to intervention across all ages and in a number of settings. In addition to educational services, 26 states in the U.S. specifically require insurers to provide coverage for the diagnosis and treatment of autism. Many children could lose access to these entitlements under the proposed DSM-V criteria.
See more of: Clinical Phenotype
See more of: Symptoms, Diagnosis & Phenotype