background Only a minority of trauma-exposed individuals develops post-traumatic stress disorder (ptsd). Contemporary conditioning models posit that associations between the representations of trauma-related stimuli are crucial to the etiology of ptsd. In conditioning terms, the individual learns that various conditioned stimuli (cs), present at the time of the traumatic event, unconditional stimulus (us), are associated with the event. Later exposure to the cs will activate memory representations of the us, which will activate associated responses, conditioned responses (cr). Interestingly, clinical studies have shown that ptsd patients show reduced extinction of autonomic responses to a previously neutral conditioned stimulus, relative to traumaexposed individuals without the disorder (Orr e.a. 2001).
aim In this prospective study, we investigated whether this reduced extinction learning may be a pretrauma vulnerability factor for ptsd.
method Dutch soldiers (n = 165) were administered a laboratory fear conditioning paradigm about six weeks before a four-month deployment to Afghanistan, while autonomic responses (heart rate, skin conductance, facial emg) wererecorded. They also completed several questionnaires that measure potential risk factors for ptsd (e.g., trait anxiety). About six months and 12 months after their return home, ptsd (symptomatology) was assessed by clinical interviews.
results We will test whether heightened physiological reactivity during extinction of learned fear predicts the persistence of ptsdsymptoms.
conclusion The results will be presented and discussed at the conference.