[Nightmares in the bedroom of science: mapping of a neglected sleep disorder]

Nightmares are intense and unpleasant dream experiences that characterize approximately 4 percent of the adult population at least on a weekly basis. Nightmare frequency is often co-morbid with other mental complaints; however, recent results indicate that nightmare disorder is independent from waking mental dysfunctions. Nightmare disorder is intimately related to poor subjective sleep quality, and according to polysomnographic studies nightmare subjects' sleep is characterized by increased sleep fragmentation and hyper-arousal. These findings suggest that instead of the psychopathological perspective nightmare disorder should be viewed as a specific sleep disorder that requires targeted treatment. Nevertheless, in order to choose the adequate treatment procedure clinicians should examine the co-morbid mental disorders as well taking into consideration the severity of nightmare distress, the latter supposed to be the mediator between nightmare frequency and waking mental dysfunctions.