This study examined the incidence of traumatic experiences and prevalence of lifetime posttraumatic stress disorder (PTSD) in a sample of 141 general hospital psychiatric inpatients. Sixty-one percent of the patients reported at least one traumatic event during their lifetime and 28% met the formal DSM-III-R criteria for a lifetime diagnosis of PTSD. A high degree of comorbidity between PTSD and other psychiatric disorders was found, but PTSD was the incident disorder in at least 50% of cases. The experience of trauma and its associated complex patterns of symptomatology suggest that PTSD complicates the process of recovery from another disorder.