Sleep patterns in children with autism spectrum disorders

Abstract

Appropriate sleep is necessary for maturation of the basic brain functions and sleep is increasingly recognized as a key process in the neuro-developmental processes. Persons with sleep disorders in early childhood, have diffi culties in cognitive functions later in life, as well as a higher incidence of psychiatric disorders. In children with autism spectrum disorders (ASD), pathological sleep patterns occur in 30% to 80% of cases. The most common pathological sleep patterns in children with ASD include diffi culty falling asleep, restless sleep, frequent nocturnal awakenings, early morning awakenings, poor sleep effi ciency, insomnia during the day, as well as nightmares, headaches, crying during sleep, apnoea, and sleepwalking. These fi ndings might be associated with pathological maturation of the circadian system leading to changes in the sleep-wake pattern. One of the key factors in regulating circadian rhythm and proper sleep is melatonin. In children with ASD, dysregulation of melatonin synthesis and release has been demonstrated, as well as changes in the expression of genes responsible for the physiological function of melatonin. Researches suggest that children with ASD have reduced melatonin levels, which is associated with pronounced autism spectrum symptoms. Therefore, in recent years, it has been suggested that desynchronization of the circadian system plays an important role in the development of ASD. The use of exogenous prolonged-release melatonin in children with ASD has been shown to be eff ective in shortening sleep latency, creating eff ective sleep duration, and reducing nocturnal and early morning awakenings. The results also indicate the benefi t of using prolonged-release melatonin in improving certain symptoms of autistic behaviour. Accordingly, by suppressing and treating sleep disorders and circadian sleep patterns in children with ASD, we can possibly contribute to reducing certain behavioural patterns characteristic of children with ASD.