Sleep Disorders May Predict Development of PTSD

Not surprisingly, persons who have been robbed, sexually assaulted, or otherwise traumatized often experience insomnia or daytime sleepiness after the event. But if such individuals go on to experience persistent insomnia and daytime sleepiness over subsequent months, it may signal that they are “coming down” with posttraumatic stress disorder.

So suggests an Israeli study reported in the May American Journal of Psychiatry.

Ehud Klein, M.D., a psychiatrist at the Rambam Medical Center in Haifa, Israel, and his colleagues selected as subjects for their study 102 individuals between the ages of 18 and 65 years old who had survived car accidents and who had been hospitalized for limb injuries or fractures. None of the subjects had experienced head injury or brain damage as a result of their accidents. Thus, Klein and his team were in a position to explore any possible links between the subjects’ psychological traumas and sleep disturbances without having to worry that the sleep disturbances might be due to head injury or brain damage rather than to psychological traumas.

The researchers then tracked, for a year, any insomnia or daytime sleepiness that the 102 subjects had. They did so by administering the Mini Sleep Questionnaire at one week into the study and again at one, three, six, and 12 months. This questionnaire has 10 questions that explore insomnia and daytime sleepiness. At the end of the year, the investigators then used the Structured Clinical Interview for DSM-III-R to assess which of the subjects had developed posttraumatic stress disorder. Twenty-six (26 percent) of the subjects had.

Klein and his team then compared the insomnia and daytime sleepiness of the 26 subjects who later went on to develop PTSD with those of the 76 subjects who did not. They found that insomnia and daytime sleepiness from one month on predicted the presence of of PTSD a year later.

Specifically, only one week after their accidents, the 26 subjects who developed PTSD scored higher on both insomnia and excessive daytime sleepiness than the 76 who did not, but the difference was statistically significant only for insomnia. At one month after their accidents, however, the 26 subjects scored significantly higher on both excessive daytime sleepiness and insomnia than the other 76 subjects. And from three to 12 months, these differences were sustained.

There was “a clear divergence of sleep-quality profiles between motor vehicle accident survivors with and without PTSD,” Klein and his colleagues concluded in their study report. “First, even though most subjects reported sleep difficulties immediately after the accident, the severity was slightly greater in those who developed PTSD. Second, this initial difference appeared to widen over the first three months and stabilize over the next nine months. These results suggest that, on the basis of sleep complaints, it is possible to detect subjects who will later develop PTSD as early as one month after the trauma.”

Before persistent insomnia and daytime sleepiness can be used to predict PTSD, the results of this study need to be confirmed by other investigators, Klein and his team wrote. A related question also needs to be answered, they pointed out: Would early treatment of sleep disturbances following a traumatic event reduce the risk of developing PTSD?

The study, “Sleep Complaints as Early Predictors of Posttraumatic Stress Disorder: A One-Year Prospective Study of Injured Survivors of Motor Vehicle Accidents,” is posted on the Web at http://ajp.psychiatryonline.org/cgi/content/full/159/5/855?. ▪