Autism Is Associated With Interindividual Variations of Gray and White Matter Morphology.

This brain imaging study looked at 183 autistic people and 157 non-autistic people to understand how their brains differ. Using advanced techniques, researchers found specific patterns of brain differences in autistic individuals, particularly in areas involved in movement, thinking, and emotional processing. They also found connections between certain brain patterns and repetitive behaviors common in autism. The study suggests that autism involves complex changes across multiple brain regions working together.

This neuroimaging study used linked independent component analysis to examine both gray and white matter brain differences in 183 autistic individuals compared to 157 non-autistic controls aged 6-30 years from the EU-AIMS LEAP dataset. The researchers identified one significant multimodal brain pattern associated with autism, involving gray matter volume changes in bilateral insula, frontal, precentral, postcentral, cingulate, and caudate regions, alongside white matter alterations in the superior longitudinal fasciculus. Brain-behavior analyses revealed significant multivariate associations between white matter variation patterns and restricted/repetitive behaviors in the autism group. The findings demonstrate the value of integrated gray and white matter analyses for understanding autism's neurobiological mechanisms and suggest that autism's complex clinical presentation relates to distributed brain covariation patterns across cortical and subcortical areas.

Findings support integrated approaches to understanding autism neurobiology rather than examining brain regions in isolation. The identified brain-behavior relationships, particularly between white matter patterns and repetitive behaviors, may inform development of more targeted interventions and provide objective measures for treatment monitoring.

The study design type is not specified in the provided information. Cross-sectional nature likely limits causal interpretations. The abstract does not detail methodological limitations, sample characteristics, or potential confounding variables that may affect generalizability of findings.

Although many studies have explored atypicalities in gray matter (GM) and white matter (WM) morphology of autism, most of them relied on unimodal analyses that did not benefit from the likelihood that different imaging modalities may reflect common neurobiology. We aimed to establish brain patterns of modalities that differentiate between individuals with and without autism and explore associations between these brain patterns and clinical measures in the autism group. We studied 183 individuals with autism and 157 nonautistic individuals (age range, 6-30 years) in a large, deeply phenotyped autism dataset (EU-AIMS LEAP [European Autism Interventions-A Multicentre Study for Developing New Medications Longitudinal European Autism Project]). Linked independent component analysis was used to link all participants' GM volume and WM diffusion tensor images, and group comparisons of modality shared variances were examined.

Subsequently, we performed univariate and multivariate brain-behavior correlation analyses to separately explore the relationships between brain patterns and clinical profiles. One multimodal pattern was significantly related to autism. This pattern was primarily associated with GM volume in bilateral insula and frontal, precentral and postcentral, cingulate, and caudate areas and co-occurred with altered WM features in the superior longitudinal fasciculus. The brain-behavior correlation analyses showed a significant multivariate association primarily between brain patterns that involved variation of WM and symptoms of restricted and repetitive behavior in the autism group.

Our findings demonstrate the assets of integrated analyses of GM and WM alterations to study the brain mechanisms that underpin autism and show that the complex clinical autism phenotype can be interpreted by brain covariation patterns that are spread across the brain involving both cortical and subcortical areas.