Which sleep disorder is characterized by abnormal behaviors during sleep, such as walking or talking?

Somnambulism, commonly known as sleepwalking, is the sleep disorder characterized by the performance of complex behaviors while in a state of sleep. During an episode, individuals may walk around, talk, or even engage in activities without being aware of their actions. This phenomenon typically occurs during non-REM sleep, particularly in the deeper stages, and can range from simple movements to more complicated activities.

Sleepwalking is not accompanied by conscious awareness; hence individuals usually have no recollection of the event once they awaken. This differentiates somnambulism from other disorders like insomnia, where the main issue is difficulty in initiating or maintaining sleep, and sleep apnea, which involves interruptions in breathing during sleep. Narcolepsy, on the other hand, is characterized by excessive daytime sleepiness and sudden attacks of sleep, rather than acting out during sleep. Therefore, somnambulism stands out as the disorder directly linked to abnormal behaviors happening during the sleep state.