The heterogeneity inherent in autism spectrum disorder (ASD) makes the identification and diagnosis of ASD complex. We survey a large number of diagnostic tools, including screeners and tools designed for in-depth assessment. We also discuss the challenges presented by overlapping symptomatology between ASD and other disorders and the need to determine whether a diagnosis of ASD or another diagnosis best explains the individual's symptoms. We conclude with a call to action for the next steps necessary for meeting the diagnostic challenges presented here to improve the diagnostic process and to help understand each individual's particular ASD profile.
Keywords: Autism; Co-occurring conditions; Diagnostic instruments; Differential diagnosis; Dual diagnosis; Lifespan.
Copyright © 2020 Elsevier Inc. All rights reserved.