Abstract
Many individuals with autism spectrum disorder (ASD) experience co-occurring internalizing problems, yet little is known about cognitive and neural mechanisms underlying this comorbidity. Repetitive negative thinking (RNT) about self-referential information is a cognitive vulnerability factor across multiple diagnostic groups with well-characterized neurobiological underpinnings. Youth with ASD may be at heightened risk for RNT due to their perseverative cognitive style, which could account for the relationship between ASD and internalizing problems. This study investigates the interaction of brain networks involved in self-referential processing (i.e., the default mode network, DMN) and cognitive inflexibility (i.e., the salience network, SN) to confer increased risk for RNT, leading to internalizing problems in ASD. The sample included youth with ASD (N=15) and typically developing (TD) youth (N=23) aged 8-13. Participants and informants completed questionnaires assessing cognitive flexibility, RNT and internalizing problems, as well as a resting-state brain scan to assess brain network integrity. Groups did not differ in levels of RNT, though youth with ASD exhibited higher rates of internalizing problems and decreased cognitive flexibility. Across both groups, cognitive flexibility was related to RNT, which in turn predicted internalizing problems. The neural mechanism underlying RNT differed for youth with ASD compared with TD youth. The TD group demonstrated the expected effect, where RNT was positively associated with functional connectivity (FC) within the DMN, while the ASD group exhibited a negative association between RNT and DMN FC. Functional connectivity of the SN did not relate to RNT in either group. Implications for understanding heterogeneity in clinical presentation, as well as promise for identifying and treating cognitive flexibility and RNT to reduce comorbid internalizing problems in ASD, are discussed.