One Size Does Not Fit All: An Individualized Approach to Understand Heterogeneous Cognitive Performance in Autistic Adults

Abstract

Cognitive performances of autistic people vary widely. When studying cognitive aging in autistic adults, this heterogeneity might have caused previous group-based comparisons to overlook those autistic adults that are particularly vulnerable for cognitive decline. The current study aimed to 1) assess the applicability of a new statistical method, namely multivariate normative comparisons (MNC), to assess cognitive performance in autism individually, 2) understand cognitive heterogeneity in autistic adults using MNC. As pre-registered, we performed MNC in a comparison sample of 254 non-autistic adults, and two independent autism samples of 118, and respectively 86 autistic adults (range: 20-85 years, mean: 50 years). MNC statistically assess cognitive deviancy on the entire cognitive profile, in an individual manner. Cognitive performance was measured on eleven outcomes in six domains (verbal/visual memory, working memory, verbal fluency, Theory of Mind, and psychomotor speed). Using MNC, about twice as many autistic individuals had a deviant cognitive profile as compared to non-autistic individuals. Importantly, most autistic individuals (>80%) did not have a deviant cognitive profile. Cognitive deviancy as indicated by MNC was significantly associated with higher levels of psychological distress in autistic adults specifically, showing the clinical relevance of this method. Therefore, MNC seem a useful tool to individually detect meaningful cognitive differences in autism. These results are consistent with previous cognitive studies suggesting that most autistic individuals show fairly similar cognitive profiles to non-autistic individuals in adulthood, but also highlight the necessity for individualized approaches which better reflect the (cognitive) heterogeneity observed in autistic people.

Tackling emotional processing in adults with attention deficit hyperactivity disorder and attention deficit hyperactivity disorder + autism spectrum disorder using emotional and action verbal fluency tasks

“…In contrast, the process-oriented measures of VFT, including clustering, switching, imaginability, and concreteness, did not differ from the NT controls (75,77). These discrepant findings may be due to the heterogeneity of ASD presentations (80,81). Indeed, autistic adults without intellectual disability have been found to produce fewer words during the first thirty seconds of letter and semantic conditions of VFT, which could be explained by an initiation deficit (82).…”