Autism-ness Does Not Exist, but Autism Does. Part 1: A Critic of the "Spectrum" Position Used to Describe, Diagnose, and Research Autism, and Its Alternative.

This article presents the historical roots of the dimensional perspective on autism, the epistemological and clinical critics of its assumptions and effects, and offers an alternative to it. Autism is increasingly being described as the "extreme far end" of a spectrum of traits distributed continuously and heterogeneously throughout the general population, and various comorbid neurodevelopmental conditions. This dimensional perspective, initially a response to the excesses of nominalism in the DSM, creates its own heuristic and clinical dead ends. In contrast with this dimensional paradigm, clinical experts recognize and diagnose prototypical autism based on the high similarity of specific clinical signs that are present during the preschool period. We propose viewing autism as a universal and evolutionarily stable, quasi-categorical possibility of human development, offering a prototypical presentation within a certain age range. We argue that prototypical autism needs to be further clinically described and scientifically investigated before anticipating the inclusion of nonprototypical presentations in an informative "autism spectrum." To achieve this, instruments based on qualitatively defined signs, with weighted diagnostic value, and universally associated with clinical certainty, must be developed. In the meantime, we recommend that all clinicians suspend the use of DSM-5 clinical specifiers to focus on clinical certainty and the application of differential diagnoses, rather than on the diagnostic thresholds of DSM-5 and of standardized instruments.