Are gender differences in post-traumatic stress disorder rates attenuated in substance use disorder patients?

Abstract

Abstract We review 15 studies that examined rates of post-traumatic stress disorder (PTSD) in substance use disorder (SUD) patients to determine whether the typical female-greaterthan-male gender difference in PTSD rates is attenuated in SUD samples. Since the majority of studies reviewed did not find a gender difference in PTSD rates, we critically examined methodological factors that might account for this attenuation, but none appeared to completely account for the variability in detection of gender differences across studies. Several factors may contribute to making rates of PTSD among SUD males equivalent to the high rates observed in SUD females: 1) the risky lifestyle associated with men's substance abuse may increase their exposure to traumatic events, 2) a history of more severe trauma characteristics may be apparent among men with SUDs, or 3) attenuated gender differences in rates of other comorbidities that increase PTSD risk (e.g., depression) may exist. Clinical implications are discussed. According to epidemiological studies, post-traumatic stress disorder (PTSD) is a highly comorbid condition among those with substance use disorders (SUDs; see review by Stewart, 1996). In the National Comorbidity Survey, a large-scale epidemiologic survey conducted in the U.S., Kessler and colleagues (1997) found that those with alcohol dependence were at 3-4 times increased risk of lifetime PTSD as compared to those without alcohol dependence. Moreover, the presence of comorbid PTSD among individuals being treated for SUDs is related to poorer treatment adherence (Hien, Nunes, Rudnick Levin, & Fraser, 2000) and outcomes, including higher relapse rates (e.g., Ouimette, Brown, & Najavits, 1998; Ouimette, Finney, & Moos, 1999). It has been suggested that if patients with comorbid SUD-PTSD were to receive trauma-specific treatment, they might avoid overutilizing or misusing expensive inpatient SUD treatments, thereby reducing the cost of clinical care (e.g., Brown, Recupero, & Stout, 1995). The delineation of gender variations in the presentation of this comorbidity may identify factors that will improve treatment outcomes (Sonne et al., 2003). A fairly consistent finding across epidemiologic studies on PTSD rates in the general adult population is that women are about twice as likely to have PTSD as men (e.g., Breslau, Chilcoat, Kessler, Peterson, & Lucia, 1999; Breslau, Davis, Andreski, & Peterson, 1991; Breslau, Davis, Andreski, Peterson, & Schultz, 1997; Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). Moreover, women experience qualitatively different traumatic life experiences than do men. These findings have led to an interest in understanding gender differences in PTSD and their implications for etiology and treatment of the disorder (e.g., Kimerling, Ouimette, & Weitlauf, in press). Early research on comorbid PTSD-SUDs focused almost exclusively on male veterans whose pathology arose in the context of combat trauma; more recently, a focus has emerged on women with comorbid PTSD-SUDs (Najavits, Weiss, & Shaw, 1997). The major purpose of this article is to examine gender as an important individual difference variable with respect to trauma and PTSD among patients with SUDs. This brief review focuses on rates of trauma and PTSD among clinical samples of male and female SUD patients. Summaries of the methods and findings of the studies reviewed in this article are provided in Tables 1 and 2, for trauma exposure rates and PTSD rates, respectively. Gender Differences in Adult Samples Brown et al. (1995) studied the prevalence of trauma histories and comorbid PTSD among 84 adults (48 male; 36 female) seeking treatment at a private hospital inpatient substance-abuse treatment program. Participants completed self-report measures of lifetime trauma exposure and PTSD symptoms. Women were more likely than men to have been physically abused/assaulted (31% vs. …