Sleepwalking through history: medicine, arts, and courts of law.

Somnambulism, or sleepwalking, has always been of interest to theologians, writers, philosophers, physicians, and others fascinated by unusual behaviors. This parasomnia, which was defined less precisely in the past than it is today, has long been featured in medical dissertations and books of medicine. Further, Shakespeare, Bellini, and Brown, among others, incorporated it into their plays, operas, and novels. Because some somnambulists turned violent and committed other acts detrimental to society, sleepwalking also demanded attention from legal systems, and guidelines were set for whether somnambulists could be held responsible for their actions. This historical review focuses on these developments pertaining to somnambulism through the seventeenth, eighteenth, and nineteenth centuries.