Objective: The purpose of this article is to further an understanding of the psychological state when aggression follows an episode of partial arousal from early non-REM sleep during which some areas of the brain appear to be functioning as in waking while others appear to remain in a state of sleep. To illustrate this, the author examines a case of homicide for which the defense argued lack of responsibility due to sleepwalking.
Method: A review of the forensic literature on sleepwalking aggression and sleep studies suggests that these fall into one or both of two DSM-IV-TR diagnoses: sleepwalking disorder and sleep terror disorder. The new case, which would meet criteria for an overlap disorder in which sleepwalking is followed by sleep terror, is compared to one previously published.
Results: These findings support sleepwalking violence as a distinct overlap disorder with common disturbed psychological functioning during and for a period up to 1 hour following an aggressive episode.
Conclusions: Research clarifies the pathology of this disorder and highlights the need to both refine the differential diagnosis and test the efficacy of treatment protocols.