Nightmares can be defined as vivid and terrifying dreams which awaken the dreamer from sleep. Typically, the dreamer wakes from the rapid eye movement (REM) stage of sleep and can remember a detailed, perhaps bizarre dream plot. There is evidence that frequent nightmares are associated with insomnia and poor-quality sleep.Nightmares are associated with a range of psychiatric symptoms, full-blown psychiatric disorders such as post-traumatic stress disorder (PTSD) and sleep disturbances. While some psychiatric, personality, sleep and biological correlates of nightmares have been described, the vast majority of extant studies are cross-sectional, precluding conclusive determination of causality and etiology.
Imagery rehearsal treatment is a promising cognitive behavioral therapy for recurrent nightmares and nightmares caused by PTSD. The technique helps chronic sufferers change their nightmares by rehearsing how they would like them to transpire. In some cases, medications may be used in conjunction with therapy to treat PTSD-related nightmares, though their efficacy has not been demonstrated as clearly as that of imagery rehearsal treatment.Nightmare disorder is a parasomnia associated usually- but not exclusively- with REM sleep. It is found in 2–8% of the general population. Sleepwalking is another frequent parasomnia. It is relatively common in childhood (3–13.5%), but its prevalence decreases during adolescence and falls to 2–4% in adulthood.A great majority of the research focuses on management of individual patients and case reports.