A Trial of the Drug Donepezil for Sleep Enhancement and Behavioral Change in Children With Autism

Background: \- Some children with autism spectrum disorders (ASD) do not have normal sleep cycles. Some of these children spend very little time in the rapid eye movement (REM) stage of sleep. Some studies suggest that less time in REM sleep can be associated with learning and behavior problems. Donepezil is a medication used to treat Alzheimer s disease. Donepezil can increase REM sleep in some adults with different disorders. A small study showed that Donepezil can also increase REM sleep in children with ASD. Researchers now want to see if Donepezil can improve communication skills and social interaction in children with ASD. They also want to see if any change in symptoms seems to come from changes in REM sleep. Objectives: \- To see if a medication, Donepezil, can improve the way communication skills and social interaction develop in young children with autism spectrum disorders. Eligibility: \- Children 22 to 44 months of age with ASD. Design: * Participants will be screened with a blood test, heart tests, and a sleep study. During the sleep study, children will sleep in a darkened room for 2 nights with electrodes on their body and a tube under their nose. Parents can sleep in the room with their child. A technician will monitor the room all night. * Participants will take the study medication once a day. * Treatment will be monitored at visits every 3 months. At each visit the participant will take blood tests, heart tests, or behavior tests. Participants will have 2 more sleep studies. * Participation will end after 18 months.