Revisiting subcortical brain volume correlates of autism in the ABIDE dataset: effects of age and sex

Background. Autism spectrum disorders (ASD) are characterized by substantial clinical, etiological and neurobiological heterogeneity. Despite this heterogeneity, previous imaging studies have highlighted the role of specific cortical and subcortical structures in ASD and have forwarded the notion of an ASD specific neuroanatomy in which abnormalities in brain structures are present that can be used for diagnostic classification approaches. Method. A large (N = 859, 6-27 years, IQ 70-130) multi-center structural magnetic resonance imaging dataset was examined to specifically test ASD diagnostic effects regarding (sub) cortical volumes. Results. Despite the large sample size, we found virtually no main effects of ASD diagnosis. Yet, several significant twoand three-way interaction effects of diagnosis by age by gender were found. Conclusion. The neuroanatomy of ASD does not exist, but is highly age and gender dependent. Implications for approaches of stratification of ASD into more homogeneous subtypes are discussed.