Excitation/Inhibition Balance as a Mechanistic Link Between Sleep Disturbance and Autism Spectrum Disorder: A Bidirectional Framework.

Sleep disturbances are highly prevalent in autism spectrum disorder (ASD), yet their significance may extend beyond that of a common co-occurring condition. Growing evidence suggests that excitation/inhibition (E/I)-related network dysregulation may provide a valuable framework for understanding the association between sleep disturbances and variability in core ASD symptom expression. This review synthesizes findings from polysomnography, actigraphy, circadian rhythm research, neuroimaging, electrophysiological studies, and animal models to examine how E/I-related vulnerability in ASD may contribute to impaired sleep initiation and maintenance. It further explores how sleep and circadian disruption may, in turn, influence daytime symptom expression through alterations in synaptic homeostasis and network rebalancing. By proposing a bidirectional framework, this review aims to integrate current evidence on sleep-related symptom variability in ASD and to inform future longitudinal, mechanistic, and biomarker-driven research.