Sleep Intervention in Children With ASD

Inclusion Criteria: * (1) Parents/caregivers with a child aged 6 to 12 years old, and attending a local mainstream primary school at the time of recruitment; * (2) The child is diagnosed to have ASD, which will be based on the assessment conducted by a psychiatrist or a clinical psychologist that incorporates the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) assessment criteria, with corroboration by the Autism Diagnostic Interview - Revised (ADI-R); * (3) The child is reported by the parent/caregiver to have insomnia symptoms, typically a difficulty in falling asleep with or without bedtime resistance, which is operationally defined as sleep onset latency exceeding 25 minutes and occurring three or more times per week. The child's sleep problems have lasted for a minimum of three months and have led to an impairment in the daily functioning of the child and/or parents. Such inclusion criteria are based on the DSM-V criteria for insomnia, with the choice of a 25-minute sleep onset latency criteria based on the normative values reported by Scholle et al.; * (4) Parent owns and knows how to use smartphones and can comprehend Chinese language; * (5) The child's parent or guardian gives written informed consent of participation into the study; * (6) Being able to comply with the study protocol. Exclusion Criteria: * (1) Children with diagnosed intellectual disability; * (2) Children with any diagnosed co-morbid neurological or medical conditions which could have affected their sleep, such as blindness, traumatic brain injury, epilepsy and poorly controlled eczema; * (3) Children with diagnosed sleep disorders other than insomnia or with suspected sleep apnoea (as assessed by the Children's Sleep Habits Questionnaire (CSHQ): obtaining a score of 4 or above on the sleep-disordered breathing subscale on the CSHQ) that may potentially contribute to a disruption in sleep continuity and quality. Children who are currently receiving regular melatonin treatment, as well as other medications such as Selective Serotonin Reuptake Inhibitors (SSRIs), will be considered for inclusion in the trial if they continue to meet the eligibility criteria.