SALT LAKE CITY — Sleep disturbances that occur in the weeks immediately after a stressor may predict later development of posttraumatic stress symptoms, data from a post-Sept. 11, 2001, survey suggest.
A total of 782 subjects from an ongoing Web-based research panel completed a measure of acute stress (the Stanford Acute Stress Reaction Questionnaire) 2 weeks after the Sept. 11 attacks, and also completed a posttraumatic stress questionnaire at 2 and 6 months after the attacks, Elaine T. Bailey, a graduate student in psychology at the University of Arizona, Tucson, reported at the annual meeting of the Associated Professional Sleep Societies.
Sleep disturbances, including trouble falling or staying asleep at 2 weeks after the attacks, had a small, but significant predictive value for development of posttraumatic stress symptoms at both 2 and 6 months after controlling for potential effects of preexisting anxiety, depression, and insomnia. Data on these preexisting conditions were available for participants from their ongoing involvement on the Web-based research panel, for which they had completed a health questionnaire before Sept. 11.
However, after controlling for the effects of acute stress symptoms in the early period after the attacks, the findings remained significant only for development of PTS symptoms at 6 months, Ms. Bailey said. The average age of the group was 49 years. About half of the members were men. Demographic distribution of the group closely matches current U.S. census counts in terms of age, sex, race, and geographical region.
These findings raise the possibility that sleep disturbance in the period immediately after a stressor might exacerbate or contribute to the development of PTS symptoms, particularly in those who develop symptoms later in the posttrauma period, she said.