Psychophysiologic reactivity, subjective distress, and their associations with PTSD diagnosis

Intense subjective distress and physiologic reactivity upon exposure to reminders of the traumatic event are each diagnostic features of posttraumatic stress disorder (PTSD). However, subjective reports and psychophysiological data often suggest different conclusions. For the present study, we combined data from five previous studies to assess the contributions of these two types of measures in predicting PTSD diagnosis. One hundred fifty trauma-exposed participants who were classified into PTSD or non-PTSD groups based on structured diagnostic interviews completed the same script-driven imagery procedure, which quantified measures of psychophysiologic reactivity and self-reported emotional responses. We derived four discriminant functions (DiscFxs) that each maximally separated the PTSD from the non-PTSD group using (1) psychophysiologic measures recorded during personal mental imagery of the traumatic event; (2) self-report ratings in response to the trauma imagery; (3) psychophysiologic measures recorded during personal mental imagery of another highly stressful experience unrelated to the index traumatic event; and (4) self-report ratings in response to this other stressor. When PTSD status was simultaneously regressed on all four DiscFxs, trauma-related psychophysiological reactivity was a significant predictor, but physiological reactivity resulting from the highly stressful, but not traumatic script, was not. Self-reported distress to the traumatic experience and the other stressful event were both predictive of PTSD diagnosis. Trauma-related psychophysiologic reactivity was the best predictor of PTSD diagnosis, but self-reported distress contributed additional variance. These results are discussed in relation to the Research Domain Criteria framework.