History
Sporadic nightmares are common in children and usually occur in the middle of the night or early morning, when REM sleep is more common.
The content of nightmares is age related, with imaginary creatures most common in 7- to 9-year-old children and being kidnapped common in 10- to 12-year-old children. [3] Other common themes are loss of control and fear of injury.
Vocalizations may occur, but movement and autonomic symptoms are minimal.
When awakened, the child becomes oriented, can be calmed, and usually recalls the details of the dream.
Good history taking allows the clinician to rule out other sleep disorders such as night terrors.
Physical
Nightmares are not associated with specific physical findings.
Heart rate and respiratory rate may increase or show increased variability before the child awakens from a nightmare. Mild autonomic arousal, including tachycardia, tachypnea, and sweating, may occur transiently upon awakening.
Movement is uncommon owing to REM sleep–induced atonia.
Causes
Developmental, genetic, psychological, and organic factors can contribute to occurrence. A high prevalence of parasomnias in early childhood has been associated with separation anxiety. [5]
Multiple studies have demonstrated that a child’s general level of anxiety is related to nightmare severity and frequency. [3]
Approximately 7% of individuals who have frequent nightmares have family history of nightmares.
Nightmares are more common in children with mental retardation, depression, and CNS diseases; an association has also been reported with febrile illnesses.
Medications may induce frightening dreams, either during treatment or following withdrawal. Withdrawal of medications that suppress REM sleep, including tricyclic antidepressants and selective serotonin reuptake inhibitors, can lead to an REM rebound effect that is accompanied by nightmares.
Nightmares are associated with anxiety disorders, particularly in adolescents. [11]
Daytime emotional conflicts and psychological stress often contaminate sleep and predispose the child to nightmares.
Nightmares may result from a severe traumatic event and may indicate posttraumatic stress disorder.
In a mainly female adult sample from the United Kingdom, nightmare occurence was associated with higher levels of worry, depersonalization, hallucinatory experiences, paranoia, and sleep duration. Nightmare severity was associated with higher levels of worry, depersonalization, hallucinatory experiences, and paranoia. [12]
In a Finnish adult population, depression and insomnia were the strongest risk factors for nightmare frequency. [13]
Nightmares may be more frequent during pregnancy. [14]
