The DSM-5 criteria were published in May 2013.1, 2 Although the DSM-5 diagnostic criteria are intended primarily for use by clinicians and researchers in their diagnostic assessments, the IACC is aware that it is important to also remember that these the criteria also have a direct impact on people who have the disorders and their families, and their ability to assess symptoms and obtain services that can help them optimize their health, well-being and quality of life. Any revision of the diagnostic criteria must be made with great care so as to not have the unintended consequence of reducing critical services aimed at improving the ability of persons with autism. In this statement, the IACC describes a range of research, practice, and policy implications that arise as a result of the changes in theDSM criteria which deserve consideration as the DSM-5 is implemented in research, clinical, and educational settings.
Changes in the DSM Criteria
Starting with the DSM-III in 1980, autism was categorized as a Pervasive Developmental Disorders (PDD). In an effort to reflect what has been learned through research and practice since that time, the DSM-5 released in 2013 removed the PDD category and the accompanying subtypes (Autistic Disorder, Asperger Disorder, Childhood Disintegrative Disorder and Pervasive Developmental Disorder – Not Otherwise Specified) with a single disorder, Autism Spectrum Disorder (ASD). The DSM-5 criteria place greater emphasis on the two core symptom domains of ASD (social communication and restrictive, repetitive behaviors), and no longer consider verbal abilities as a diagnostic feature. Other changes included adding ratings of the severity of the two symptom domains and several clinical specifiers. These specifiers provide information about etiology, co-morbidities (e.g., intellectual disability, language delay, and medical conditions such as seizures), and pattern of onset.
Since ASD continues to be defined by a pattern of developmental and behavioral symptoms, changes to the diagnostic criteria come with potential trade-offs. One goal of the recent revisions was to improve specificity of the ASD diagnosis, reducing the number of false positive cases. However, concerns exist that this increased specificity may have gone too far in reducing the sensitivity of the ASD diagnosis, increasing the number of false negative cases. For example, removing a specific age cut-off for diagnosis was intended to improve the sensitivity of theDSM-IV criteria (which had required symptom onset by 3 years of age). By DSM-5's more inclusive criterion, "Symptoms must be present in the early developmental period but may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies in later life" may reduce diagnostic specificity by expanding the list of differential diagnoses that must be considered. The inclusion of historical information also may have unintended consequences on sensitivity and specificity.
Another major change in DSM-5 was the addition of a new diagnosis category, Social Communication Disorder (SCD)which applies to individuals who exhibit persistent difficulty with the social use of verbal and nonverbal communication that cannot be explained by low cognitive ability. The symptoms of SCD have significant overlap with those of the ASD social communication domain, but the two disorders are considered to be unique and separate from each other. The distinction is clarified in the DSM-5 criteria, which note that ASD must be ruled out before a diagnosis of SCD can be considered. However, there is limited published information on SCD with a research basis primarily in the condition previously studied as Pragmatic Language Disorder (PLD). While SCD includes PLD, there is much to learn about the definition, measurement, scope, reliability, and validity of SCD as a diagnosed condition.
