The purpose of this study is to determine if liquid supplemental melatonin is an effective treatment for children with autism who have sleep problems related to insomnia (difficulty falling asleep).

Sleep difficulties in children with autism spectrum disorders (ASD) are common reasons why parents seek medical intervention for their children. Identifying a safe and effective pharmacologic agent that promotes sleep in ASD would favorably impact the lives of these children and their families. In this study we plan to determine the dose-response, tolerability and any adverse effects of supplemental melatonin in 30 children with ASD.The melatonin dose levels are 1mg, 3mg, 6mg, and 9mg. After a 3 week baseline period, the child will begin melatonin at 1mg and will dose escalate every three weeks until he/she is falling asleep within 30 minutes of bedtime at least 5/7 nights per week. No child will take more than 9 mg of supplemental melatonin.

Inclusion Criteria:

• Children with autism ages 4-10 years.
• Diagnosis of autism based on Autism Diagnostic Observation Schedule (ADOS).
• Time to fall asleep of 30 minutes or longer by parent report at least 3 nights/week in the last 3 months.
• Children may take seasonal allergy medications.
• Children may take the following medications for the same dose at least 3 months: Citalopram (Celexa), Escitalopram (Lexapro), Amphetamine-dextroamphetamine (Adderall), Atomoxetine (Strattera), Methylphenidate(Ritalin), Dextroamphetamine(Dexedrine), Risperidone (Risperdal.

Exclusion Criteria:

• Children taking medications other than those in the inclusion criteria.
• Children with primary sleep disorder other than insomnia (such as sleep-disordered breathing).
• Children with non-febrile unprovoked epileptic seizure within the last two years.
• Children with liver disease or high fat diets, as melatonin metabolism may be affected in these children.
• Children who are visually impaired (partially or completely blind) as light suppresses melatonin synthesis and these children may have altered diurnal melatonin rhythms.
• Children with known genetic syndromes co-morbid with autism including fragile X, Down syndrome, neurofibromatosis, or tuberous sclerosis.
• Children who have outside normal limits on blood work for complete blood count, liver and renal function and hormone levels of ACTH, cortisol, LH, FSH, prolactin, testosterone and estradiol.
• Tanner staging beyond level 1 at any time point in the study.
• Children whose assessment score does not place them on the autism spectrum.