Impact of emotion on cognition in trauma survivors: What is the role of posttraumatic stress disorder?

Background: Cognitive theories of anxiety disorders postulate an increased attentional bias to environmental cues associated with threat that underlies the exaggerated fear response. The role of trauma, which may represent strong competitive advantage for attention, remains unclear. We investigated the influence of trauma exposure and the presence of anxiety/stress disorders on the impact of emotional distractors on cognitive performance. Methods: Fourteen trauma-exposed subjects with PTSD, 12 trauma-exposed subjects with anxiety disorders other than PTSD, 12 trauma-exposed healthy subjects and 19 non-trauma-exposed healthy controls participated in this study. The impact of emotion on cognition was determined by the Affective Stroop task that measures the effect of irrelevant emotional distractors on the speed of operant responding. Results: The speed of cognitive performance was significantly reduced in the presence of negative distractors versus neutral or positive distractors in subjects with PTSD, while there was no significant influence of the distractor type on performance in the other diagnostic groups (diagnosis-by-distractor type interaction, p < 0.001). While negative distractors induced the same levels of anxiety and depersonalization in subjects with PTSD and subjects with other anxiety disorders, distractor-induced depersonalization was associated with slowing of cognitive performance in PTSD (p = 0.02) but not in other groups. Limitations: Different types of anxiety disorders in the non-PTSD group might reduce the selectivity of the results; some subjects received medication possibly impacting on their cognitive functioning. Conclusions: The cognitive impairments in the presence of negative distractors specifically found in PTSD call for research into novel psychotherapeutic approaches, e.g. attentional training, for PTSD.