Autism Spectrum Disorders in Adulthood: Empirical Findings on Comorbidities, Differential Diagnoses, and the Clinical Utility of the AQ

Abstract

Autism spectrum disorders (ASD) often remain undiagnosed until adulthood. The aim of this study is to report differential diagnoses (DDX) and comorbidities of adults without intellectual impairment suspected of having an ASD and to test the self-assessment questionnaire Autism Quotient (AQ) for its suitability for screening. Methods DDX and comorbidities were recorded with standardized scales in an autism outpatient clinic in 106 individuals. The AQ was tested against the expert judgment of an interdisciplinary case conference using ROC analysis. Results Affective disorders were common in both groups (48%); other DDX were phobias (33%) and personality disorders (22%). The AQ showed an AUC of 0,527 with sensitivity/specificity of 70%/35%. Conclusions Adults suspected of having autism are highly burdened by DDX and comorbidities. An interdisciplinary diagnostic procedure based on standardized scales is useful, whereas the AQ hardly differentiates between persons with and without ASD.