Overview of Sleepwalking
Sleepwalking is a common type of parasomnia (i.e., condition that occurs during sleep and creates a disruptive event) called an arousal disorder. Sleepwalking, which also is called somnambulism, is more prevalent in children.
Sleepwalkers (somnambulists) are aroused out of their deep sleep during motor activity, which usually includes, but is not limited to, walking.
A sleepwalker can go back to sleep some place other than bed, depending on how far he or she has walked. Sleepwalkers are usually unaware of their activity. Some cases of autonomic (independently functioning) behavior that occur with sleepwalking involve dressing and even eating.
What causes sleepwalking is unknown. Most people have sleepwalked on at least one occasion. Sleepwalking poses no serious health threat to those who experience it, although the risk of injury, however minor, is a matter of concern. Injury prevention is the primary objective of sleepwalking management.
Sleepwalking is currently being evaluated in a social and legal context—responsibility for criminal actions during sleepwalking is being determined.
Incidence of Sleepwalking
Sleepwalking affects approximately 1% to 17% of children and is more frequently seen in boys. The incidence of sleepwalking decreases with age. Although the exact prevalence of sleepwalking in adults is not known, it is estimated to be as high as 10%. The cause for decreased incidence in adults is also not known. Evidence from casework and published sleep diaries indicates that sleepwalkers often feel they are alone with their condition. This is not the case.
Current Research on Sleepwalking
Currently, there is nonspecific medical evidence that suggests that there may be psychiatric issues involved in sleepwalking and that the actions of sleepwalkers in certain cases may not be autonomous and need to be reevaluated.
For example, in Britain, a man actually killed someone while sleepwalking. The issue is whether or not to acquit the defendant on the basis of autonomic actions or to find him insane and, therefore, release him to treatment for mental illness. Subsequently, there is controversy surrounding an individual's right to plead insanity in cases like this, which complicates our perspective of agency in sleepwalking behavior. Sleepwalking is not currently defined or treated as a mental illness.
Future research may involve the development of a medical-legal definition of sleepwalking. Of course, cases like this are rare, but the media coverage of it is greatly responsible for public recognition of sleepwalking.