Ever woken up and found yourself with half a sandwich in your mouth and you just can’t remember how it got there? Have you ever found yourself in your pyjamas in the middle of the street and can’t recall how you got there? Well if you have, chances are you suffer somnambulism or commonly called sleepwalking, a mysterious disorder which is reportedly suffered by 1 in 25 adults. Before we start a common myth should be dispelled, it is not dangerous to wake up someone who is sleepwalking. It is recommended that you don’t startle them and slowly walk them back to their bed, but if the person is in immediate danger, waking them is probably the best option.
The DSM-V (diagnostic and statistical manual of mental health disorders version five) defines sleepwalking as “repeated episodes of rising from bed during sleep and walking about, usually occurring during the first third of the major sleep episode. While sleepwalking, the person has a blank, staring face, is relatively unresponsive to the efforts of others to communicate with him or her, and can be awakened only with great difficulty”. The episodes can last from a few minutes to half an hour. The majority of sufferers develop sleepwalking as a child but most people grow out of it. This results in a relatively small population of adult sufferers. It is unknown why children sleepwalk more than adults, but it has been theorised it is related to the activity in a developing child’s brain being different to adults.
So what causes sleepwalking? Well the cause is unknown. What is known is that there appears to be some form of genetic link in relation to sleepwalking. Sufferers who come from a family where one parent suffers the condition are 45% more likely to develop it. This number jumps to 60% if both parents suffer from the condition. There also appears to be some relation to other disorders and sleep walking. Sufferers with schizophrenia, hysteria, anxiety neuroses, Tourette and even people who suffer migraines have all shown to have a high incidence of sleepwalking.
Besides this, the only other information we have surrounding sleepwalking is when it occurs in the sleep cycle. The sleep cycle can be divided into two stages Non-REM and REM (Rapid Eye Movement). REM sleep is the deep stage of sleep, where a person dreams. The body is put in a “paralysis” like state, in order not to act out dream. This goes against the myth that people sleep walking are acting out their dream. Sleep walking occurs during Non-REM sleep, where the person is unconscious but the body has not yet activated the “paralysis” like state yet. This means the person is free to move about.
Although very little is known about the underlying causes for sleep walking, there are things which can. These include:
not getting enough sleep
stress and anxiety
infection with a fever (especially in children)
drinking too much alcohol
taking recreational drugs
certain types of medication, such as some sedatives
being startled by a sudden noise or touch, causing abrupt waking from deep sleep
waking up suddenly from deep sleep because you need to go to the toilet
The little we understand about sleepwalking makes the extreme actions some people commit under an episode even more bizarre. One such example comes from Manchester in the case of Jules Lowe, who murdered his father during an episode. The jury acquitted Mr Lowe after it was concluded that he could not have performed the action voluntary. This is one of the few cases where the defence of sleepwalking has actually worked, in relation to homicide.
To conclude we know that sleep walking occurs during Non-REM sleep and that the majority of sleepwalkers are children. We also know some triggers that can result in an episode, but generally speaking, sleepwalking isn’t something to lose sleep about.