Defining the Optimal Threshold Scores for Adult Autism Subthreshold Spectrum (AdAS Spectrum) in Clinical and General Population

• Published in: Clinical practice and epidemiology in mental health Vol. 16; no. 1; pp. 204 - 211
• Main Authors: Dell'Osso, Liliana, Carmassi, Claudia, Cremone, Ivan Mirko, Muti, Dario, Salerni, Antonio, Barberi, Filippo Maria, Massimetti, Enrico, Gesi, Camilla, Politi, Pierluigi, Aguglia, Eugenio, Maj, Mario, Carpita, Barbara
• Format: Journal Article
• Language: English
• Published: United Arab Emirates Bentham Science Publishers 2020
• Subjects: Autism Spectrum Disorder; Psychometric instrument; AdAS Spectrum; RAADS; Diagnostic threshold; Autistic traits
• ISSN: 1745-0179; 1745-0179
• DOI: 10.2174/1745017902016010204

The Adult Autism Subthreshold Spectrum (AdAS Spectrum) is a recently developed instrument tailored to assess the broad range of full-threshold as well as sub-threshold manifestations related to the autism spectrum. Although it has proved to be a valuable instrument for quantitative assessment of autistic symptoms, the AdAS Spectrum still lacks validated diagnostic thresholds. The aim of this study was to define the best cut-off scores of the AdAS Spectrum for determining the presence of subthreshold autistic traits as well as a clinically significant autism spectrum disorder (ASD). Our sample was composed of 39 patients with full-blown ASD, 73 subjects with autistic traits, and 150 healthy controls. Subjects were evaluated by trained psychiatrists, who performed a clinical diagnosis according to DSM-5 and then assessed with the AdAS Spectrum and the Autism Spectrum Quotient. Our results showed that the most discriminant cut-off scores were 70 for identifying subjects with full-blown ASD, and 43 for determining the presence of significant autistic traits. The threshold values proposed here showed satisfying levels of specificity and sensibility, as well as a good agreement with the diagnosis according to DSM-5 criteria, confirming the validity of the AdAS Spectrum as a psychometric tool for measuring ASD-related conditions in the clinical and general population.