Clinical and Circadian Aspects of Poor Sleep Quality

This presentation will briefly cover basic information about sleep structure, sleep as a circadian rhythm, and the impact of poor sleep quality as a background to discussion of the clinical and circadian aspects of sleep difficulties in autism spectrum disorder and their impact across the lifespan. Sleep has a circadian structure, with 24-hour cycles of waking and sleeping governed by the suprachiasmatic nucleus, and the neurohormone melatonin. The primary zeitgeber for the sleep-wake cycle is the light-dark cycle.Likewise the sleep EEG structure and pattern changes through infancy and early childhood, resulting in approximately 90-minute cycles of rapid eye movement sleep (REM) and non-REM sleep in children and adults. Poor sleep quality can negatively impact learning and memory, mood and behaviour, and physical health. While there is a vast array of sleep problems, the most common are those associated with sleep onset and maintenance, and insufficient sleep. Sleep disorders most commonly associated with these symptoms include behavioural sleep disorders in childhood, insomnia, and circadian sleep-wake rhythm disorders (CSWRDs). Poor sleep in autism begins in early childhood, when sleep patterns begin to deviate from those of age-matched peers, continuing into at least middle age. Across this age range some 50-80% of autistic individuals will suffer from significant symptoms of insomnia or CSWRDs, and at least in childhood, these sleep problems are often chronic. Sleep problems in children with autism spectrum disorder can also have a significant behavioural component. In autism associations between poor sleep quality and intensified autistic symptomatology, aggression, peer relationships, psychopathology, unemployment, screen time, gastrointestinal symptoms, melatonin and clock genes are reported. Parents’ sleep and wellbeing is also affected. Nevertheless, the aetiology of increased susceptibility to poor sleep quality in autistic individuals remains unknown. There are likely subgroups and multiple causal factors including hyperarousal and differences in the melatonin rhythm. Research that examines aetiology, impacts on the individual with autism, and intervention is required.