Implicit and explicit avoidance in sexual trauma victims suffering from posttraumatic stress disorder: a pilot study

Avoidance of stimuli that are associated with the traumatic event is a key feature of posttraumatic stress disorder (PTSD). Thus far, studies on the role of avoidance in the development and maintenance of PTSD focused primarily on strategic or explicit avoidance. However, patients may also show implicit avoidance behavior, which may remain even when explicit avoidance is reduced. The present pilot study was designed to test the hypothesis that PTSD patients show implicit avoidance of threatening, trauma-related stimuli. In addition, it was tested whether this avoidance behavior also occurs for other stimuli. The Approach-Avoidance Task was used as an indirect measure of avoidance. Participants were 16 women suffering from PTSD who had experienced a sexual trauma, and 23 healthy non-traumatized women. Using a joystick, they pulled pictures closer to themselves or pushed them away. The pictures varied in content, being either high-threat sexual, non-threat sexual, high-threat accident, or positive. Compared to control participants, PTSD patients avoided high-threat sexual pictures, and the degree of avoidance was predicted by self-reported arousal level. Moreover, PTSD patients with high levels of self-reported explicit avoidance, depressive symptoms, and PTSD symptom severity also avoided high-threat accident pictures. These findings point to the possible importance of threat value instead of trauma-relatedness in explaining implicit avoidance. The results are discussed in light of cognitive-behavioral models of PTSD, and clinical implications are suggested.