Nightmares and Post-traumatic Stress Disorder

Frightening Dreams: The Nightmare

Nightmares are vivid and terrifying nocturnal episodes in which the dreamer is abruptly awakened from sleep. Typically, the dreamer wakes from REM sleep and is able to describe a detailed, associative, often bizarre dream plot. Usually, the dreamer has difficulty returning to sleep. In a two-week study of college students, 47 percent described having at least one nightmare. Results of a general population study of 1,049 persons with insomnia revealed that 18.3 percent had nightmares. In this study, nightmares were more common in women and were associated with increases in nocturnal awakenings, sleep onset insomnia, and daytime memory impairment and anxiety following poor nocturnal sleep. Studies of the general population reveal that 5 to 8 percent of the adult populations have a current problem with nightmares.

Nightmares affect 20 to 39 percent of children between 5 and 12 years of age. Contrary to popular belief, frequent nightmares in children do not suggest underlying psychopathology. Nightmares are often described by creative persons who demonstrate "thin boundaries" on psychologic tests. Persons with thin boundaries are less likely than others to define the world around them in concrete terms. They rarely define issues as being black and white, but instead see themselves and the world in shades of gray.

Nightmares are also associated with the use of medication, primarily those medications that affect neurotransmitter levels of the central nervous system, such as antidepressants, narcotics or barbiturates. Intense, frightening dreams may occur during the withdrawal of drugs that cause REM sleep rebound, such as ethanol, barbiturates and benzodiazepines.

Nightmares and Post-traumatic Stress Disorder

Nightmares are a defining symptom in post-traumatic stress disorder (PTSD). The latter is not a new disorder. In 1667, after the great fire of London, Samuel Pepys wrote, "To this very day I cannot sleep a-night without great terrors of the fire." Nightmares related to PTSD occur after an intensely frightening or highly emotional experience. These nightmares are often associated with disturbed sleep and altered daytime behavior, which is best described as hyperarousability.

The occurrence of PTSD following trauma varies. Thirty percent of veterans of the Vietnam War were affected by PTSD, as were 68 percent of veterans who were in the Arab-Israeli conflict of 1973 and 8 percent of veterans of the Gulf War. Among the civilian population, PTSD affects approximately 25 percent of persons who have experienced emotional and physical trauma or have suffered a severe medical illness. However, among some groups of patients, such as psychiatric patients, the incidence of PTSD approaches 40 percent.

The frequency of PTSD increases with severity of trauma, hostility, depression and poor health habits. Persons with PTSD generally report awakening from dreams that involve reliving the trauma. In these dreams, they experience strong emotions, such as rage, intense fear or grief, that would have been appropriate reactions to the original traumatic event. Nightmares related to PTSD generally happen during REM sleep but also occur at sleep onset, which can interfere with the initiation of sleep. Polysomnographic studies in these patients have shown that they have poor sleep maintenance, increased eye movement density, decreased percentage of REM sleep and an increased tendency to have REM sleep at sleep onset (REM pressure). This phenomenon is similar to that occurring in patients with narcolepsy. Recurrent nightmares are the most defining symptom of post-traumatic stress disorder.

Symptoms of PTSD can persist for decades after the traumatic experience; however, the occurrence of PTSD after trauma is the exception rather than the rule. Patients who experience PTSD are divided into two groups based on the presence or absence of impaired psychologic functioning before the trauma.

Date: 2015-12-11; view: 766