ELEVATED AWAKING THRESHOLDS DURING SLEEP - CHARACTERISTICS OF CHRONICWAR-RELATED POSTTRAUMATIC-STRESS-DISORDER PATIENTS

Background: Sleep disturbances are one of the hallmarks of posttraumat ic stress disorder (PTSD); however, sleep laboratory, studies have pro vided inconsistent evidence of the existence of objective sleep distur bances in PTSD patients. Reports that awaking thresholds from sleep in war-related PTSD patients were significantly elevated compared to nor mals are discordant with complaints of insomnia. The present study inv estigated 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 polysomnog raphic recordings for 4 nights. Awaking thresholds to clicks were dete rmined during I night, and dreams were collected during 2 nights. Pati ents' symptoms were assessed by the Zung and Beck depression scales, I mpact of Events Scale, State and Trait Anxiety, and Symptom Check List questionnaires. Results: Although there were no significant differenc es between sleep data of patients and controls, PTSD patients had sign ificantly higher awaking thresholds. Awaking thresholds were significa ntly positively related to depression and anxiety scores. Patients' dr eams were significantly more aggressive and hostile, and in 6 patients they included explicit war-related contents. The severity of the clin ical picture was significantly related to the dreams' scores of aggres sion-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.