The investigators will examine whether sleep problems in children with autism spectrum disorder (ASD) are related to alterations in the production of melatonin (MT), a hormone that plays an important role in regulating sleep-wake cycle. Children with ASD experience high rates of sleep disturbances that potentially contribute to problems with thinking and behavior. It is unclear if changes in MT production cause sleep problems in children with ASD. MT is frequently used to treat these sleep problems; however, it has not been well established whether MT is an effective treatment. Our hypotheses concerning MT is children with ASD and sleep problems will have a delayed sleep-wake cycle and/or decreased MT production. This study will compare children diagnosed with ASD to "healthy" control children with no ASD diagnosis. All subjects will be recruited from one of three sites: Baylor College of Medicine, Oregon Health & Science University and Columbia University. The investigators will use a standardized questionnaire to determine whether the child has sleep problems. The investigators will measure MT levels in saliva in ASD children with sleep problems and in a group of control children without sleep problems. Total 24-hour MT production will be determined from urine samples in these same two groups.

This is a proposal to study the relationship between melatonin (MT) and sleep problems in children with autism spectrum disorder (ASD), as part of the collaborative research structure of the Autism Treatment Network (ATN). A major goal of the ATN is to conduct clinical research that will have a significant impact on the daily lives and functioning of individuals with ASD and to address immediate concerns of parents. Children with ASD experience high rates of sleep disturbance, which likely contribute to the severity of their daytime cognitive and behavioral dysfunction and to poorer quality of life for them and their families.

As a step toward addressing sleep problems in ASD, we propose to test the hypothesis that children with ASD and sleep problems will have a delay in MT onset and/or have decreased MT secretion over 24 hours compared to normal controls.

Primary endpoint: Characterize the endogenous MT profiles in children with ASD:

We predict that results from this study will reveal lower levels of metabolized MT in children with ASD when compared to normal children. In addition, we anticipate that children with ASD will have delayed MT onset or altered circadian phase.

Data from this study will provide important information concerning circadian rhythm dysregulation in ASD and will support the development of future studies using MT to modify and correct abnormal circadian rhythms.

Inclusion Criteria:

1. Diagnosis of Autism Spectrum Disorder; supported by ADOS and the ADI or SCQ (subjects).
2. Age greater than or equal to 4 or less than or equal to 9 years;
3. Parents have given informed consent.
4. Parent/Caregiver fluent in written and spoken English.
5. Controls only: A SCQ score of less than 10 without parental or physician concern for another neurodevelopmental disorder will be used to define normal children.

Exclusion Criteria:

1. Current use of psychoactive medications (e.g. fluoxetine, methylphenidate, risperidone, lithium, etc.)*;

2. Current or use within the last 1 month of beta-blockers or melatonin;

3. Current use of sleep aids;

4. Presence of untreated medical problems that could otherwise explain sleep problems (e.g. obstructive sleep apnea, gastroesophageal reflux disease - GERD);

5. Blindness.

6. Controls only: current or past diagnosis of ADHD, depression, anxiety or with any other psychiatric conditions. (7) Controls only: Sibling has a diagnosis of Autism Spectrum Disorder.

   • Psychoactive medications can be discontinued but the parents must discuss medication discontinuation with their prescribing physician prior to reducing or stopping the medications.

Children with the diagnosis of ASD and that are not diagnosised with ASD (controls).