MedicalResearch.com: What are the main findings of the study?
Dr. Leventhal: In the American Psychiatric Association’s Diagnostic and Statistical Manual for Mental Disorders, 5th Edition (DSM5) released in May 2013, changes include major alterations in criteria for developmental disorders, in particular, the DSMIV diagnostic criteria for Pervasive Developmental Disorder (PDD), including elimination of subtypes found in DSMIV such as Asperger Disorder and PDD NOS. Additionally, DSM 5 adds a new diagnostic category, Social Communication Disorder (SCD): individuals with SCD have difficulties similar to ASD but these problems are solely restricted to the realm of social communication and do not include the restrictive and repetitive behaviors found in ASD.
Apparent differences between DSMIV PDD and DSM5 ASD criteria have led to debates, in both the scientific and lay communities, over whether these changes in diagnostic criteria will: materially affect ASD prevalence; alter the way individuals will be diagnosed with ASD; and, possibly, the eligibility of individuals for clinical and other services. Such debates are creating controversy amongst professionals, as well as confusion and anxiety for service providers, policy makers, and, most importantly, for patients and their families.
In order to answer these pressing questions, we computed DSM5 ASD and SCD prevalence and compare them to DSMIV PDD prevalence estimates, utilizing our published, total-population Korean prevalence data. We also describe individuals previously diagnosed with DSMIV PDD when diagnoses change with DSM-5 criteria.
The target population was all 7-12-year-old children in a South Korean community (n= 55,266), those in regular and special education schools and a disability registry. We utilized the Autism Spectrum Screening Questionnaire for systematic, multi-informant (both parents and teachers) screening. Parents of screen-positive children were offered comprehensive assessments using standardized diagnostic procedures, including the Autism Diagnostic Interview-Revised (ADI-R) and Autism Diagnostic Observation Schedule (ADOS). Board certified child and adolescent psychiatrists made consensus best estimate clinical diagnoses using DSMIV PDD and DSM5 ASD and SCD criteria.
DSM5 ASD estimated prevalence is 2.20% (CI: 1.77-3.64). Combined DSM-5 ASD and SCD prevalence (0.49%) is virtually the same as DSM-IV PDD prevalence (2.64%). Most children with Autistic Disorder (99%), Asperger Disorder (92%), and PDD NOS (63%) met DSM-5 ASD criteria, whereas 1%, 8% and 32%, respectively, met SCD criteria. All remaining children (2%) had other psychopathology, principally Attention Deficit Hyperactivity Disorder (ADHD) and anxiety disorder. These data provide essentially no support for the concerns that individuals affected with DSMIV PDD will “lose a diagnosis” with the advent of DSM5.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Leventhal: When ASD and SCD are combined, then virtually everyone with a DSMIV PDD remains on the “new spectrum.” Since, until proven otherwise, the treatments for ASD and SCD remain the same or similar, it is important for children moving to SCD (and their families), to continue receiving the interventions they received with the DSMIV PDD diagnosis. And, for those falling out of the DSM5 ASD/SCD group, they appear to have other significant and impairing disorders that are also important and certainly deserve the care and attention appropriate for those conditions; clinicians should promptly point these children in the right directions, even though ASD is not that direction. Whether the label is PDD, ASD or SCD, extant diagnostic criteria are helpful in identifying a relatively large, clinically meaningful group of individuals and families who deserve comprehensive evaluations and evidence-based treatments, as early as possible.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Leventhal: There is a need to follow up the DSMIV- DSM 5 divergent children to understand the natural course and outcomes of their conditions and how they are related or unrelated to ASD.