Exploring the multidimensional nature of repetitive and restricted behaviors and interests (RRBI) in autism: neuroanatomical correlates and clinical implications.

The study excluded people with IQ below 70, so it says little about autistic people with intellectual disability. Brain associations were based on 152 MRI participants, a small subset of the 792, and none survived correction for multiple comparisons. The MRI subsample was unbalanced: 42 autistic people, 89 relatives and 13 controls. The study was cross-sectional, so it cannot show how symptoms or brain volumes change over time. Symptoms were measured with separate autism and OCD scales, so the clusters may reflect the tools as much as the condition. The study did not include comorbidities or executive dysfunction as covariates. The study did not investigate gender differences because females were too few.

Funding came from Assistance Publique - Hôpitaux de Paris, Institut Pasteur, Fondation FondaMental, Roche Institute for Research and Translational Medicine, INSERM, Fondation de France, Fondation à la Recherche Médicale and Investissements d'Avenir program. The supplied text does not state author conflicts of interest.

Do not use the putamen findings to guide assessment or therapy. The brain-volume associations did not survive the authors' correction for multiple comparisons, and the study did not test a treatment.