No evidence of sleep disturbance in post-traumatic stress disorder: A polysomnographic study in injured victims of traffic accidents

Background: Disturbed sleep is a common complaint among patients with PTSD. This complaint can be found in both the reexperiencing and hyperarousal symptom clusters in the DSM-IV. However, laboratory studies of sleep in PTSD have provided inconsistent evidence of objective sleep disturbances. Shortened REM latency, reduced sleep efficiency, restless sleep and increased prevalence of sleep apnea have been reported, but were not confirmed by all. A major shortcoming of most previous studies is the fact that they were done retrospectively in patients with chronic PTSD, often complicated by psychiatric comorbidity and drug abuse. Thus, little is known about the development of sleep disturbances in recently traumatized subjects. Method: Eight injured victims of traffic accidents with PTSD and 6 injured victims without PTSD participated in a 3-night polysomnographic study one year after the accident. Results: No significant differences between PTSD and non-PTSD patients were noted on any of the PSG measures. In addition, the two groups did not differ significantly from each other with respect to awakening thresholds during REM sleep. Conclusion: Considering that the present sample was free of active psychiatric comorbidity at the time of trauma and free of hypnotic medications, these results strengthen previous PSG studies suggesting that altered sleep perception, rather than sleep disturbance per se, may be the key problem in PTSD. More research is needed in order to examine whether this problem is specific to sleep or generalizes to other domains as well.