Sleepwalking is a common parasomnia affecting up to four percent of adults. It involves complex behaviors that occur during arousals from non-rapid eye movement (NREM) sleep. During an episode of sleepwalking the brain is partially awake, resulting in complex behaviors, and partially in NREM sleep with no conscious awareness of actions. Triggering factors that increased both the frequency and severity of episodes were reported in 59 percent of the study participants. These factors , related mainly to:
- stressful events
- strong positive emotions
- sleep deprivation
- drug or alcohol intake
- intense evening physical activity
Such factors tend to promote increased slow wave sleep (SWS) and NREM sleep instability.