Nightmare disorder

Nightmare disorder is a sleep disorder characterized by repeated intense nightmares that most often center on threats to physical safety and security. The nightmares usually occur during the REM stage of sleep, and the person who experiences the nightmares typically remembers them well upon waking. More specifically, nightmare disorder is a type of parasomnia, a subset of sleep disorders categorized by abnormal movement or behavior or verbal actions during sleep or shortly before or after. Other parasomnias include sleepwalking, sleep terrors, bedwetting, and sleep paralysis.

Nightmare disorders can be confused with sleep terror disorders. The difference is that after a sleep terror episode, the patient wakes up with more dramatic symptoms than with a nightmare disorder, such as screaming and crying. Furthermore, they do not remember the reason of the fear, while a patient with a nightmare disorder remembers every detail of the dream. Finally, the sleep terrors usually occur during NREM Sleep.

Nightmares also have to be distinguished from bad dreams, which are less emotionally intense. Furthermore, nightmares contain more scenes of aggression than bad dreams and more bad endings. Finally, people experiencing nightmares feel more fear than with bad dreams.

The treatment depends on whether or not there is a comorbid PTSD diagnosis. About 4% of American adults are affected. Studies examining nightmare disorders have found that the prevalence rates ranges 2–6% with the prevalence being similar in the US, Canada, France, Iceland, Sweden, Belgium, Finland, Austria, Japan, and the Middle East.