About 1 in 100 people has experienced sleepwalking. In many TV series or movies about sleepwalking, characters will get up during sleep and walk around, clean the house, move furniture, cook, and even drive on the highway. You might think that this is just an exaggerated film-making style, which unlikely to happen in reality. But the truth is, all the above behaviors are common in sleepwalking.
Do sleepwalkers act out their dreams?
You may think that the behavior of sleepwalkers is based on the content of their dreams. In fact, sleepwalking occurs during the stage of non-rapid eye movement (NREM) sleep when dreaming is rare. Sleepwalking usually occurs within 1-2 hours after falling asleep, and the process lasts approximately 1-30 minutes. Sleepwalkers may only sit up in bed or simply wander in the house. They may also put themselves in dangerous or embarrassing situations, such as climbing windows, urinating in inappropriate places, or driving. During the episode, sleepwalkers’ eyes are usually open, if you observe carefully, you will find that their eyes are out of focus. It is usually very difficult to wake them up, and they usually have no memory of the event after waking up.
What triggers sleepwalking?
Sleepwalking is a kind of “parasomnia”, which is usually occurs in children, with a proportion as high as 17%. This may be related to the undeveloped brain’s ability to regulate sleep/wake cycles. In addition, genetics and family history are also the important factors. If parents have sleepwalking, the chance of their children having sleepwalking increases 2-3 times. But no need to worry too much, because sleepwalking often diminishes as children grow older. And the prevalence of sleepwalking in adults is estimated to be up to 4%, which is mostly related to sleep deprivation, stress or anxiety.
Does sleepwalking need to be treated?
Doctors generally believe that treatment is not necessary for sleepwalking. Unless the episodes are more frequent and involve dangerous behaviors, or the episodes last into adulthood and affects daily life. If so, you should seek medical attention as soon as possible. The doctor may recommend you schedule a PSG sleep test in the hospital.
A classic case of sleepwalking murders
A sleepwalking murder occurred in Canada in 1987 can be described as a global shock. It was made into a movie. Many scholars still using this as a case study for their research. On the night of the incident, a 24-year-old man drove 14 miles to the home of his wife’s parents in the middle of the night and attacked them. His mother-in-law died and his father-in-law survived. After the incident, he drove to the police station and surrendered. The police found that he seems to be unconscious, because he did not appear to be in pain despite having cut tendons in both hands. After investigation, based on his family history of sleepwalking and his sleep test report, it was determined that he was sleepwalking at the time and was acquitted at the end.
 The Institute of Mental Health (IMH), Castle Peak Hospital: https://www3.ha.org.hk/cph/imh/docs/20120207_chi.pdf
 Harvard Health Publishing: https://www.health.harvard.edu/staying-healthy/sleepwalking-and-sleep-terrors-a-to-z
 American Academy of Sleep Medicine (AASM): http://sleepeducation.org/sleep-disorders-by-category/parasomnias/sleepwalking/symptoms-risk-factors
 U.S. News & World Report: https://health.usnews.com/health-news/family-health/sleep/articles/2009/05/08/7-criminal-cases-that-invoked-the-sleepwalking-defense