Characteristics of patients with nocturnal dissociative disorders

Frequency of nocturnal dissociative episodes (NDE) in patients with dissociative disorders (DD) was determined and clinical characteristics of patients with nocturnal dissociative disorders was compared with those DD only. Extensive overnight polysomnographic monitoring with nocturnal video-polysomnography was performed in 8 patients with NDE and 21 patients with DD only. We found a 27.5% prevalence of NDE in patients with DD. A clear transition from one personality to another was observed during sleep in 2 (about 7%) patients. Hallucinations, self-mutilating behaviors during sleep, and violent behavior during sleep were more common in the patients with NDE. Sleep may facilitate the transition from one personality to the other one. Patients with DD may use dissociation as a defense mechanism during sleep.