The RAADS was designed to address a major gap in screening services for adults with autism spectrum disorders. With the increased prevalence of the condition and the fact that adults are being referred or self-referred for services or diagnosis with increasing frequency, this instrument is a useful clinical tool to assist clinicians with the diagnosis of this growing population of higher functioning individuals in adulthood. This study was designed to standardize the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R) in a large number of subjects at nine centers on three continents.
The RAADS-R is a modified version of the Ritvo Autism Asperger’s Diagnostic Scale (Ritvo et al. 2008
). The rationale for its development was the need for a clinical adjunct diagnostic tool. While several diagnostic scales for children and adolescents with ASD are available (Attwood 1998
; Ehlers et al. 1999
), only one peer- reviewed scale, The Autism-Spectrum Quotient (AQ) was designed specifically for adults (Baron-Cohen et al. 2001
). Its authors emphasize that it is useful in identifying autistic traits and as a screening instrument but not as a diagnostic tool. The AQ is mailed in by the participant, unlike the RAADS-R, which is designed to be administered by a clinician in a clinical setting. Baron-Cohen et al. (2005
) propose a diagnostic system as well: The Adult Asperger’s Assessment (AAA): A Diagnostic Method. While the AAA is a good system, it is a complete diagnostic system, unlike the RAADS-R. It is lengthy and complicated to administer and is still relatively new. The initial RAADS was developed around the same time period. The original RAADS contains 78 empirically derived questions that assess symptoms based upon DSM-IV-TR (American Psychiatric Association 2000
) and ICD-10 World Health Organization (1992
) diagnostic criteria that were extensively tested prior to inclusion on the scale. It proved accurate in discriminating autistic and Asperger’s subjects (N
= 37) from comparison subjects (N
= 57) when tested (e.g., sensitivity = 1, specificity = 1). Seventy-six of the 78 questions significantly distinguished ASD subjects from comparison subjects (Ritvo et al. 2008
Questions on the initial RAADS assess developmental pathology in three symptom areas: language, social relatedness, and sensory-motor (re: DSM-IV-TR). After critical review and the results of a factor analysis, a revised 80-item version was developed (the RAADS-R) with the addition of a fourth symptom area (circumscribed interests), two questions, and several word clarifications. Like the RAADS, the RAADS-R is a self-report instrument, designed for adults (18 +) with average or above average intelligence.
In order to validate the RAADS-R, a uniform research protocol was developed to be implemented at nine research centers on three continents. The protocol assured uniformity of diagnosis and data acquisition, and its implementation in multiple centers afforded an opportunity to assess the applicability of the scale in a variety of international clinical settings: (a) UCLA; (b) The Child Study Center, Yale University; (c) University of Utah; (d) Mt. Sinai Medical School, New York; (e) The Geneva Center, Toronto, Canada; (f) King’s College, London, England; (g) Monash University, Melbourne, Australia; (h) Griffith University, Brisbane, Australia; and (i) ASPECT, Sidney, Australia.
At the time this research was concluding, the American Psychiatric Association’s DSM-V committee proposed new diagnostic criteria for Autism Spectrum Disorders (APA DSM-5 2010
These new guidelines propose combining individuals who meet the DSM-IV-TR criteria for Autistic Disorder and Asperger’s Disorder into one category called Autistic Spectrum Disorder (ASD). The results of this study will present subjects grouped according to both the DSM-IV-TR and proposed DSM-V criteria. There has been ongoing controversy among clinicians about the relationship of autism and Asperger’s disorder. Diagnostic approaches and definitions are described in the literature (Fitzgerald and Corvin 2001
; Klin et al. 2005
; Volkmar and Lord 1998