Rapid eye movement and non-REM sleep parasomnias

Parasomnias comprise the behavioral, experiential, and autonomic nervous system disorders surrounding rapid eye movement (REM) and non-REM sleep and can cause injuries, sleep disruption, and adverse health effects. Parasomnias often involve the abnormal release of instinctual drives, such as locomotion, aggression, feeding, and sex during sleep, and can manifest with dream-enacting behaviors. Parasomnias are relevant to psychiatrists in regards to their misdiagnosis as a psychiatric disorder; their nocturnal extension of a daytime psychiatric disorder; their stress-responsivity; their induction or aggravation by psychotropic drugs; their adverse psychologic consequences; their link to various neurologic and medical disorders; and their forensic implications. Parasomnias can be categorized as primary disorders of sleep, or as secondary organ system disorders emerging during the sleep period. The evaluation of parasomnias includes clinical interviews, review of medical records, screening psychologic tests, neurologic examination, and hospital-based polysomnographic monitoring. This article discusses the six most prominent behavioral parasomnias: REM sleep behavior disorder, sleepwalking, sleep terrors, confusional arousals (including abnormal sleep related sexual behaviors and severe morning sleep inertia), sleep related eating disorder, and sleep related dissociative disorders. Parasomnias can appear at any time in the human life cycle, often demonstrate prominent gender discordances, and can usually be accurately diagnosed and effectively treated.