Psychological Trauma: Theory, Research, Practice, and Policy The Influence of Externalizing Comorbidity on Psychophysiological Reactivity Among Veterans With Posttraumatic Stress Disorder Kathryn L. Humphreys, Kristen M. Foley, Brian A. Feinstein, Brian P. Marx, Danny G. Kaloupek, and Terence M. Keane Online First Publication, March 28, 2011. doi: 10.1037/a0022644 CITATION Humphreys, K. L., Foley, K. M., Feinstein, B. A., Marx, B. P., Kaloupek, D. G., & Keane, T. M. (2011, March 28). The Influence of Externalizing Comorbidity on Psychophysiological Reactivity Among Veterans With Posttraumatic Stress Disorder. Psychological Trauma: Theory, Research, Practice, and Policy. Advance online publication. doi: 10.1037/a0022644