Somnambulism (often also referred to as Nocturnal Somnambulism) describes a condition in which an individual repeatedly sleep-walks. In Psychology, it is classified as a dissociative disorder, which also includes amnesia, fugue, and multiple personality disorders. Somnambulism is now thought to be a relatively benign disorder, and is usually not treated. However, there is a risk that the person could be injured accidentally (walking into things, falling down stairs, etc.) during sleep walking.