At the initial assessment, 71 percent of the women and 50 percent of the men met symptom criteria for PTSD. The incidence of PTSD decreased to 42 percent of the women and 32 percent of the men by the fourth assessment; and at the final assessment, 21 percent of the women but none of the men remained with PTSD. An examination of specific PTSD symptoms showed that many subjects who were not diagnosed with PTSD at the final assessment retained significant symptoms of PTSD, particularly re-experiencing and arousal symptoms. The severity of PTSD did not decrease significantly over the course of the study, but only in those groups that were not diagnosed with the disorder at the final assessment. Women who were diagnosed with PTSD at the final assessment did not show a significant decrease in symptom severity over the course of the study. The results are discussed regarding implications for understanding the development and persistence of posttrauma pathology, and directions for future research are outlined. 2 tables, 2 figures, and 21 references