- 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.