Role of the Sleep Laboratory in the Evaluation of Hypnotic Drugs

Pioneering studies evaluating hypnotic drugs in the sleep laboratory have been conducted by two groups: Oswald and his colleagues in Scotland and our group in the USA. In 1965, Oswald and Priest published their classical study that introduced an innovative design including three successive study conditions: placebo baseline, drug administration and placebo withdrawal22. The investigators were able to observe marked changes in sleep stages during drug administration and following drug withdrawal. Moreover, they were able to correlate these changes with clinical findings such as frequency and intensity of dreaming and their subjects’ feelings. Specifically, they found that a rebound increase in REM sleep following drug withdrawal was correlated with an occurrence of unpleasant dreams and nightmares.