Does physiologic response to loud tones change following cognitive–behavioral treatment for posttraumatic stress disorder?†

There are now a number of effective treatments for post-traumatic stress disorder (PTSD) including exposure-based therapies (Foa et al., 1999; Rothbaum & Foa, 1992) and cognitive therapies (Resick et al., 2008; Resick, Monson, & Gutner, 2007; Resick, Nishith, Weaver, Astin, & Feuer, 2002; Resick & Schnicke, 1992, 1993). Most of the studies have quantified treatment outcome in terms of a reduction in self-reported symptoms of PTSD. There is, however, very little information about more objective changes in symptoms following treatment of PTSD. One way of generating more objective measures of therapy outcome is to examine changes in physiological responses to treatment. Psychophysiological measures have demonstrated utility as a means to correctly identify participants who have PTSD from those who do not (Pole, 2007). Orr, Lasko, Shalev, and Pitman (1995) and Orr, Solomon, Peri, Pitman, and Shalev (1997) have calculated the sensitivity and specificity of psychophysiological indices such as heart rate (HR) and skin conductance (SC) responses to traumatic imagery in combat samples to predict PTSD diagnostic status. Findings for diagnostic sensitivity range from 60 to 90% and the specificity from 80 to 100% across multiple studies (Pitman & Orr, 1993). These findings suggest that psychophysiological assessment holds promise to classify individuals with PTSD objectively. There are, however, only a few reports in the literature of this type of methodology being applied to the interpretation of treatment efficacy. A study of motor-vehicle accident survivors with PTSD showed that after cognitive–behavioral treatment, participants demonstrated significant decreases in HR to audiotaped descriptions of the accident compared to a supportive psychotherapy or a waitlist condition (Blanchard et al., 2002). Most other reports of physiological response to PTSD treatment have relied on case-study designs. Many of these studies report that a positive treatment outcome is associated with a reduction in physiological arousal to reminders of the traumatic event (Boudewyns & Hyer, 1990; Fairbank & Keane, 1982; Keane & Kaloupek, 1982; Nishith, Griffin, & Weaver, 2002; Shalev, Orr, & Pitman, 1992). A number of studies have found that trauma victims with PTSD exhibit heightened startle reactivity and/or a failure to habituate to repeated stimuli when startle is measured in the psychophysiological laboratory. These include studies of male combat veterans (Butler et al., 1990; Morgan, Grillon, Southwick, & Davis, 1995; Orr et al., 1995, 1997), male police officers (Pole, Neylan, Best, Orr, & Marmar, 2003) female survivors of sexual assault (Morgan, Grillon, Lubin, & Southwick, 1997), female survivors of childhood sexual abuse (Metzger et al., 1999), as well as studies of mixed trauma samples (Shalev, Orr, Peri, & Schreiber, 1992). It should be noted that not every study of startle reactivity has produced heightened responses for PTSD-positive participants (e.g., Jovanovic, Norrholm, Sakoman, Esterajher, & Kozaric-Kavacic, 2009). An examination, however, of effect size for eye-blink electromyogram (EMG) and commonly measured autonomic responses to startling auditory stimuli reveals that the average effect sizes fall into the medium to large range (Metzger et al., 1999; Pole, 2007). In the present study, we investigated whether successful treatment of PTSD was associated with a reduction in response to loud tones. Specifically we compared female trauma survivors who successfully completed treatment as evidenced by no longer having a diagnosis of PTSD with those who completed treatment, but still had PTSD.