LOSS OF TRUST: CORRELATES OF THE COMORBIDITY OF PTSD AND SEVERE MENTAL ILLNESS

The prevalence of post-traumatic stress disorder (PTSD) in the general population of the United States is a topic of speculation, with estimates ranging from 0.4% to 9% (Breslau, Davis, Andreski, & Peterson, 1991; Helzer, Robins, & McEvoy, 1987; Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). Likewise, estimates of the prevalence of PTSD within the population of persons with serious mental illness have varied widely, depending on how PTSD has been measured. While record verification of PTSD within mental health outpatient samples has routinely been very low (0%-3%), research assessments of PTSD have resulted in estimated rates of co-occurrence of 29% to 43% (Cascardi, Mueser, DeGirolomo, & Murrin, 1996; Craine, Henson, Colliver, & MacLean, 1998; Mueser et al., 1998). A lack of documentation of PTSD in clinical records and inattention to PTSD in clinical diagnoses are thought to greatly underestimate the extent of PTSD within mental health treatment populations. The general consensus among researchers has been that the occurrence of PTSD is much higher within the population of persons with diagnoses of mental illness than in the general population, particularly among those who have major depression (Friedman & Rosenheck, 1996).