Sleepwalking – it’s usually harmless
PEOPLE have long been fascinated with sleepwalkers – by those who roam during the night without awareness, climbing out of windows, walking down the street, urinating in a cupboard, or moving furniture.
Sleepwalking is one of a number of behaviours that can occur during deep sleep, known as the “non-rapid eye movement” (non-REM) period of sleep. Others may include talking, sitting up, or just making odd body movements. It’s a relatively common sleep phenomenon with an estimated 7% of people sleepwalking at some time during their lives.
Sleepwalking isn’t necessarily considered a sleep disorder, unless it occurs repeatedly, includes amnesia and causes distress.
Sleepwalking seems to be more common in children, with estimates that about 5% of children have sleepwalked at least once in the previous 12 months compared with 1.5% of adults. The decrease in observed sleepwalking is not well understood, but may be the result of brain maturation, decreased non-REM sleep as we get older and hence fewer opportunities to sleepwalk, or adults being less likely to be observed sleepwalking than younger children.
It is not yet known why some people sleepwalk and others don’t. Sleepwalking happens when some parts of our brain, particularly the limbic system (responsible for emotions) and the motor cortex (responsible for complex motor movements) are awake, while the rest of the brain is asleep.
The underlying cause of sleepwalking is not known. Sleepwalkers have their eyes open, but are relatively unresponsive to what is going on around them. They perceive the environment differently and don’t recognise people they know.
For most people, sleepwalking doesn’t cause any problems and sleepwalkers often consider it an interesting quirk. However, some people may suffer injuries while sleepwalking, from falls or bumping into things. Children who frequently sleepwalk may be worried about going on school camps or sleepovers for fear of sleepwalking. Adults may forego travelling.
On rare occasions, sleepwalkers have been violent towards others, thinking they were responding to someone threatening. Some sleepwalkers have also sexually assaulted someone else during sleepwalking, a phenomenon known as sexsomnia. On very rare occasions, sleepwalkers have died while sleepwalking or have killed people.
In research we conducted which is yet to be published, we found violence during sleepwalking is mediated by biological, psychological and social risk factors that affect impulse control.
What to do?
If you are a sleepwalker, or someone in your family is, there are some things you can do to help minimise the risk of injury, including keeping furniture in the same place and not leaving things on the floor which could be a tripping hazard.
Deadlocks on doors and windows can help prevent sleepwalkers wandering outside, but it is important to ensure they can escape in case of a fire.
Sleepwalkers who are violent can minimise harm to themselves and others by removing objects that could be potential weapons from bedside tables.
It was once thought you shouldn’t wake a sleepwalker because it could harm them – there is no evidence for this. But because they are in the deepest stage of sleep, they will be confused if woken. While sleepwalking doesn’t normally cause daytime tiredness, most likely because the sleepwalker is still asleep, waking the sleepwalker may disrupt their sleep, which in turn may affect how they feel in the morning. If someone in your home is sleepwalking, it is best to just tell them to go back to bed, or gently lead them back to their room.
To date, there have been no clinical trials evaluating the effectiveness of treatments for sleepwalking, though myriad psychological and pharmacological treatments have been used.
If parents are concerned about their child sleepwalking, one of the most promising treatments that doesn’t have side-effects, is scheduled waking. This involves waking the child about 20 minutes before they normally sleepwalk.
Once they are awake, you let them go back to sleep. This should be continued nightly for about three weeks.
Stallman is a senior lecturer in clinical psychology at the University of South Australia.