Sleepwalking could run in families and can be passed from parents to their offspring, according to a new study out of Canada. This new insight could lead to a new understanding of a common disorder.

Sleep terrors, similar to nightmares but much more frightening, and which take place in children, also seem to correlate with an increased risk of sleepwalking later in life, according to researchers. Some of these events will lead a child to not even recognizing his or her own parents when they awake.

Researchers examined 1,940 children in Quebec over the course of 12 years. The subjects were born between 1997 and 1998, and the research team tracked the children from 1999 to 2011. The children answered questions about sleep terrors and sleepwalking, and parents were polled about nocturnal walking by themselves and their children.

They found that parents who were sleepwalkers when they were young had a higher-than-normal risk of seeing the same condition in their offspring. If both parents experienced nocturnal walking when they were children, their children were found to have more than a 60 percent risk of the same condition.

The study found that up to 33 percent of the children who experienced night terrors later went on to walk in their sleep as they grew older.

Sleepwalking is fairly common in childhood, and it usually disappears as the child reaches adolescence. The behavior is less common among children around the age of 4 but is experienced by 13.4 percent of children by age 10. The disorder can also continue in later years, even through adulthood.

"Children with one parent who was a sleepwalker had three times the odds of becoming a sleepwalker compared with children whose parents did not sleepwalk; and children whose parents both had a history of sleepwalking had seven times the odds of becoming a sleepwalker, according to the results," researchers reported in a press release.

Sleep terrors are often marked by screaming and extreme fear that persists even after the parent(s) console and comfort the child. Each of these parasomnias is believed to be related to slow-wave sleep.

In all, the study found that 22.5 percent of children from parents who never walked in their sleep experienced the behavior at least once. Having one parent with a history of the disorder raised the risk to 47.4 percent. Children born of two parents with sleepwalking in their past experienced the disorder in 61.5 percent of cases.

"It's definitely genetic. Prevention is really the cure in these situations. You want to make sure the child is not overtired, stressed out, over-scheduled. And have a nice calming ritual at bedtime so the child can actually calm himself down before going to sleep," Hansa Bhargava from Children's Healthcare of Atlanta said.

Analysis of sleepwalking and the role genetics can play in that disorder and night terrors was detailed in the journal JAMA Pediatrics.

Photo: Chris Winters | Flickr