New York, December 1: A new study suggests that night terrors in which children display sudden bouts of fear and screaming an hour or two after sleep, seems to have a strong hereditary component.
Dr Jacques Montplaisir, a professor of neuroscience and psychiatry at the University of Montreal stated, “The study brings strong evidence that genetics play a major role.”
An examination of 390 sets of twins, demonstrated that identical twins had a greater chance of experiencing night terrors than fraternal twins. Following them from birth, Dr Jacques assessed them for sleep disorders at 18 months and then 30 months as a part of the Quebec Newborn Twin Study.
Identical twins share practically the same genesdefine while fraternal twins have only half their genes in common. A comparative study of the effects of genes and environment became the focus of his research. The results revealed that 37 percent of the twins had sleep terrors at 18 months with the problem dropping to 19.7 percent by 30 months.
The researcher further determined that 43.7 percent of the child’s sleep terror was genetic at 18 months and 41.5 percent of the risk was genetic at 30 months.
Environmental factors not shared by the twins were also responsible for the risk. Sleep terror can be related to separation, anxiety and tension in the family. Psychological and physiological factors also attribute to sleep horrors in children.
Dr Adam Moscovitch, medical director of the Canadian Sleep Institute believed, “It can very much be, because especially in that age group, waking up and not having the reassuring or assuring presence of a parent physically in the immediate proximity can trigger it. That is where the whole concept of getting attached to your teddy bear or your blanky or sucking your thumb as a relaxing thing as replacement.”
Night fright occurs about two hours after the child falls asleep. It is a confusional arousal, which lasts for ten minutes or it may be as short as one minute. Sometimes it may linger for much longer, for about 40 minutes. Montplaisir explained that “the sleep terrors are an abrupt and frightening sensation associated with sudden arousal and screams. And contrary to nightmares the child does not remember anything.”
The child is confused, disoriented and inconsolable. The event is a storm of neural emissions in which a child experiences an intense flight or fight sensations. Efforts to wake up the sufferer increase their agitation and prolong the episode. “Otherwise most episodes will be brief and will cease abruptly and the child returns to sleep afterwards.” added Dr Jacques.
Explaining further Moscovitch said the sleep terrors are “The typical experience that triggers a night of terror related phenomenon, a sense of being in danger, either running away from it or responding to it.” He reassured parents that it is a transient condition common in children which usually disappears before adolescence. It is not linked to cognitive or behavioral problems in children.
The study was published in the US journal Pediatrics.