Elevated awaking thresholds during sleep: Characteristics of chronic war-related posttraumatic stress disorder patients

Background: Sleep disturbances are one of the hallmarks of posttraumatic stress disorder (PTSD); however, sleep laboratory, studies have provided inconsistent evidence of the existence of objective sleep disturbances in PTSD patients. Reports that awaking thresholds from sleep in war-related PTSD patients were significantly elevated compared to normals are discordant with complaints of insomnia. The present study investigated the relationship between awaking threshold from REM sleep in war-related PTSD patients and their dream recall, dream content, and clinical condition. Methods: After informed consent was obtained from 12 PTSD patients and 12 controls, they were investigated by polysomnographic recordings for 4 nights. Awaking thresholds to clicks were determined during I night, and dreams were collected during 2 nights. Patients' symptoms were assessed by the Zung and Beck depression scales, Impact of Events Scale, State and Trait Anxiety, and Symptom Check List questionnaires. Results: Although there were no significant differences between sleep data of patients and controls, PTSD patients had significantly higher awaking thresholds. Awaking thresholds were significantly positively related to depression and anxiety scores. Patients' dreams were significantly more aggressive and hostile, and in 6 patients they included explicit war-related contents. The severity of the clinical picture was significantly related to the dreams' scores of aggression-hostility, and to sleep quality variables, Conclusions: Elevated awaking thresholds from sleep are a characteristic finding in chronic war-related PTSD patients, which may help to explain the diverse sleep laboratory findings in this syndrome. (C) 1998 Society of Biological Psychiatry.