Many neurodevelopmental disorders adversely affect sleep; children often have difficulty in falling asleep, wake up more often during the night, and sleep less than their typically developing peers. ‘Sleep problems’ were found in 53% of over 300 children with autism, compared with 44% of 63 children with delayed development, and 32% of 163 children with normal (typical) development.1 Sleep problems arise from complex interactions between biological, psychological, social, family and cultural factors. Circadian sleep rhythm disorders (CSRD) may be acute but are more often chronic, and frequently result in associated health problems. CSRDs usually exacerbate any pre-existing learning and behavioural difficulties, and may affect the entire family's whole health and well-being and impair their ability to continue in employment or further education.

There is considerable pressure for both parents and paediatricians to try and improve a child's disturbed sleep. Management options include behavioural, or pharmacological, or both. Behavioural interventions are probably undervalued, but may be difficult to implement, and may take weeks or months to show any benefit. Conventional medications including hypnotics and sedatives are frequently associated with unacceptable day-time sedation that may adversely affect the child's quality of life. The past 20 years have witnessed the introduction of melatonin which continues to be increasingly prescribed to many children both with and without neurodevelopmental disorders and using a wide range of doses. To many, it is the ubiquitous safe solution to any ‘sleep problem’. The popularity of melatonin reflects the …