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

Liliana Dell’Osso,Claudia Carmassi,Eugenio Aguglia,Camilla Gesi,Dario Muti,Filippo Maria Barberi,Barbara Carpita,Enrico Massimetti,Ivan Mirko Cremone,Antonio Salerni,Pierluigi Politi,Mario Maj

doi:10.2174/1745017902016010204

Abstract

Background: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.Objective: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).Methods: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.Results: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.Conclusion: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.

Highlights

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 Autism spectrum disorder (ASD)-related conditions in the clinical and general population
The mean age was significantly different amongst groups (F(2.259)= 9.20; p < .001): in particular, the group with autistic traits showed a mean age significantly lower when compared with both the ASD group (p = .007) and the healthy controls (HC) (p < .001)
No significant gender differences were found between HC and subjects with autistic traits as well as between subjects with autistic traits and patients with ASD, while HC showed a significantly higher proportion of females when compared with the ASD subjects (Chi-square = 13.22, p < .001) ( Table 1)

Summary

Introduction

DSM-5, these diagnoses have been merged into the broader label of ASD [4, 5] This choice went in the direction of a dimensional approach to psychopathology, according to the purpose of classifying psychiatric disorders on the basis of both common clinical presentations and shared pathophysiology, in the framework of a link between symptomatic manifestations and brain functioning [1, 4 - 7]. DSM-5 classification of ASD does not encompass the broader spectrum of ASD milder (or atypical) manifestations and subthreshold autistic traits, whose relevance is increasingly gaining attention in the recent literature [5, 8 - 12]. The recent interest in investigating autistic traits is justified by the body of evidence that highlighted how such features, when subthreshold, may be associated with significant clinical correlates, including a higher vulnerability towards the development of psychiatric disorders and suicidal ideation and behaviours [20, 25, 26]. It has proved to be a valuable instrument for quantitative assessment of autistic symptoms, the AdAS Spectrum still lacks validated diagnostic thresholds

Methods

Results

Discussion

Conclusion