Characterizing associations between emotion dysregulation, anxiety, and repetitive behaviors in autistic youth with intellectual disability.

There is a paucity of research that explores associations between emotion dysregulation and the expression and severity of core and co-occurring characteristics of autism spectrum disorder (ASD), especially in autistic youth with co-occurring intellectual disability (ID). This study explored the interplay between developmental characteristics and emotion dysregulation, anxiety, and specific subtypes of RRBs that are elevated in autistic youth with co-occurring ID. Generalized additive models demonstrated that age, sex, language level, dysregulation, and anxiety showed unique patterns of association with subtypes of RRBs in a sample of 150 autistic youth with co-occurring ID who are non-speaking or minimally verbal. More specifically, higher anxiety levels were significantly associated with elevations in repetitive sensory motor behaviors (RSMB), self-injurious behaviors (SIB), insistence on sameness (IS), and unusual interests (UI). While emotion dysregulation was a significant predictor of UI, it demonstrated positive, albeit not significant, associations with the intensity of SIB and RSMB. Language level was a significant predictor of RSMB, such that the intensity of RSMB was higher for individuals who were non-speaking relative to those who spoke in single words. These findings provide preliminary insights into patterns of associations between emotion dysregulation, anxiety, and specific subdomains of RRBs in autistic youth with ID.