Sleep disturbance is associated with increased repetitive sensorimotor behaviour in autism but not in learning/intellectual disabilities or ADHD: A comparative study

The interplay of sleep and sensorimotor processing is a fundamental neurobiological process crucial for well-being. Individuals with neurodevelopmental conditions like autism, ADHD, and learning disabilities frequently experience both significant sleep disturbance and repetitive sensorimotor behaviours. Although a link between these domains is established, it is unclear whether this relationship and its functional impact are consistent across different neurodevelopmental conditions. In a cross-sectional dataset of individuals aged 5-21 (n = 212), we investigated whether the interplay between sleep disturbance and repetitive sensorimotor behaviours differs between individuals diagnosed with autism (IQ>70), ADHD, a learning disability (IQ<70), as well as typically developed controls. We also examined whether interactions between sleep and repetitive sensorimotor behaviours predicts distinct functional outcomes between neurodevelopmental groups. We found that individuals with autism (IQ>70) were most strongly affected by both sleep disturbance and repetitive sensorimotor behaviours. Crucially, we show that while a robust bidirectional link between sleep and repetitive sensorimotor behaviours exists across the entire sample, sleep problems amplify repetitive sensorimotor behaviours more strongly only in autistic people than in typical controls. Contrary to previous work, we found that learning disabled children and adolescents engaged in more repetitive sensorimotor behaviour but did not experience more sleep disturbance. Although the interaction between sleep problems and repetitive sensorimotor behaviours did not determine functional outcomes in autistic people, the interplay of sleep problems and repetitive sensorimotor behaviour impaired social awareness in people with ADHD. These findings challenge a transdiagnostic view that treats the reinforcement between sleep and sensorimotor problems as a general marker of neurodevelopmental conditions. Understanding the distinct pathways between sleep and waking behaviours is a critical step toward developing personalized, mechanistic interventions targeting specific sleep and sensory impairment profiles in different neurodevelopmental conditions.