Exploring the association between sleep disturbances and repetitive behaviors in autistic children and adolescents: a systematic review

Introduction Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by difficulties in social interaction and the presence of restricted and repetitive behaviors (RBs), which can be distinguished into lower and higher-level RBs. Autistic individuals frequently experience sleep disturbances that may be related to the autistic core features, particularly RBs. However, the current literature on this topic is fragmented. This systematic review aims to examine the relationship between RBs and sleep difficulties in autistic children and adolescents, also exploring whether this relationship varies between lower versus higher-level RBs. Method This systematic review followed PRISMA guidelines and it is registered in PROSPERO (ID CRD420250644207). The search in the PubMed, Psycinfo, PsycArticles, and Scopus databases yielded 379 unique English-language records According to inclusion/exclusion criteria, 21 records were considered eligible. Results Eleven studies explored the relationship between RBs and sleep disturbances, without distinguishing between lower and higher-level RBs. The remaining records examined the relationship between RBs and sleep disturbances considering the two different levels of RBs. All studies found a clear relationship between RBs and sleep difficulties, although mixed evidence emerged regarding lower-level RBs (i.e., self-injurious behaviors). Various hypotheses were proposed regarding the associative links between RBs and sleep disturbances. Further, some studies underscored that the relationship between RBs and sleep could be modulating by emotional symptoms, such as anxiety. Conclusion The reviewed studies support the connection between sleep disturbances and RBs in autistic children and adolescents. This relationship appears to vary based on the levels of RBs and the presence of co-occurring symptoms.