One size does not fit all: An individualized approach to understand heterogeneous cognitive performance in autistic adults.

Researchers studied thinking skills in autistic adults using a new method that looks at each person individually rather than comparing groups. They tested 204 autistic adults on memory, thinking speed, and social understanding. While some autistic adults showed different thinking patterns, most (over 80%) had similar thinking skills to non-autistic people. Those with different patterns experienced more stress, suggesting this approach could help identify who might need extra support.

This study examined cognitive performance in autistic adults using Multivariate Normative Comparisons (MNC), a statistical method that assesses individual cognitive profiles across multiple domains. The research included 254 non-autistic adults and 204 autistic adults (ages 20-85) across two independent samples. Cognitive performance was measured across 11 outcomes in six domains including verbal/visual memory, working memory, verbal fluency, Theory of Mind, and psychomotor speed. Results showed that approximately twice as many autistic individuals had statistically deviant cognitive profiles compared to non-autistic individuals.

However, most autistic adults (>80%) showed typical cognitive profiles. Deviant profiles were associated with higher psychological distress in autistic adults, demonstrating clinical relevance.

MNC appears useful for individually assessing cognitive differences in autism, potentially identifying vulnerable individuals who may benefit from targeted interventions. The approach recognizes autism heterogeneity and could inform personalized support strategies, particularly for those showing cognitive deviancy and associated psychological distress.

Study limitations are not explicitly stated in the abstract. The cross-sectional design limits understanding of cognitive changes over time. The method's predictive validity for cognitive decline in autistic populations requires further validation.

Cognitive performances of autistic people vary widely. Therefore, previous group-based comparisons on cognitive aging in autistic adults might have overlooked those autistic adults that are particularly vulnerable for cognitive decline. Multivariate normative comparisons (MNC) statistically assess individual cognitive differences on the entire cognitive profile. Cognitive deviancy as indicated by MNC accurately predicts future cognitive decline, and is therefore sensitive in detecting meaningful cognitive differences.

The current study aimed to (1) investigate the applicability of MNC to assess cognitive performance in autism individually, and (2) understand heterogeneous cognitive performance in autistic adults. As pre-registered, we performed MNC in a sample of 254 non-autistic adults, and two independent samples of respectively 118, and 86 autistic adults (20-85 years, mean: 50 years). Cognitive performance was measured on 11 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 (i.e., deviated statistically from the multivariate normspace) as compared to non-autistic individuals.

Importantly, most autistic individuals (>80%) did not have a deviant cognitive profile. Having a deviant profile 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 adults show fairly similar cognitive profiles to non-autistic adults, yet highlight the necessity for approaches reflecting the heterogeneity observed in autistic people.