⁃ Participants will meet the following

• Outpatients between 8 and 17 years of age with only 12- 17 years of age at time of consent during year 1

• Diagnostic and Statistical Manual, 5th edition (DSM-5) criteria for Autism Spectrum Disorder (ASD) on the basis of clinical evaluation, confirmed with the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule, 2nd Ed (ADOS-2)

• Males and females

• Availability of polysomnography (PSG) and/or actigraphy data

• Sleep disturbances as assessed using Children's Sleep Habits Questionnaire (CSHQ) with a score of 41 or higher and sleep efficiency of 85% or less and/or total sleep time less than 7 hours and/or wake after sleep onset of more than 30 minutes as measured by polysomnography (PSG) or actigraphy.

• care provider who can reliably bring participant to clinic visits, provide trustworthy ratings, and interacts with participant on a regular basis

• stable medications for at least 2 weeks, with the exception of Prozac which is required to be stable for at least 4 weeks

• no planned changes in psychosocial and biomedical interventions during the trial

• willingness to provide additional saliva samples and participate in key study procedures (i.e., safety measurements every visit, PSG at weeks 4 and 8, and wear the actigraphy watch for 2 weeks before the beginning of trial as well as during the 8 weeks of the trial)

• requirement of dual protection contraception use in females who are sexually active and are of childbearing potential. Dual use contraceptive methods involve the use of both a hormonal method (oral contraceptives, long-acting reversible contraceptives, etc.) and a barrier method (condoms).