WE PREVIOUSLY reported that altered sleep patterns occur during the administration and following withdrawal of glutethimide (Doriden), methyprylon (Noludar), and pentobarbital (Nembutal).¹ The clinical problems associated with these alterations, such as unpleasant dreams, nightmares, drug dependency, and insomnia, were also discussed. These studies suggested that further investigation of the effects of other drugs would be necessary in order to find hypnotics which did not result in sleep alterations and adverse clinical disturbance. Preliminary findings suggested that the nonbarbiturate hypnotics chloral hydrate (Noctec),² flurazepam (Dalmane) ,^3,4 and methaqualone (Quaalude)⁵ might fulfill these requirements. We decided, therefore, to systematically study each of these hypnotic drugs.

MethodsÌý Subjects were male, 20 to 30 years of age without any medical illnesses, allergies, drug use, or sleep disturbance. During the experiment they were instructed to continue to abstain from using any drugs, including alcohol, to maintain their usual level of physical