Associations Between Childhood Trauma and Emotion-Modulated Psychophysiological Responses to Startling Sounds: A Study of Police Cadets Nnamdi Pole University of Michigan Thomas C. Neylan, Christian Otte, Thomas J. Metzler, Suzanne R. Best, Clare Henn-Haase, and Charles R. Marmar University of California, San Francisco, and San Francisco VA Medical Center Childhood trauma may confer risk for adult psychopathology by altering emotional and physiological responses to subsequent stressors. Few studies have distinguished effects of childhood trauma from effects of current Axis I psychopathology on adult psychophysiological reactivity. The authors exposed 90 psychiatrically healthy police cadets to startling sounds under increasing threat of shock while assessing their eyeblink electromyogram (EMG), skin conductance (SC), and heart rate responses. When compared with those who did not endorse early trauma (n = 65), cadets reporting childhood trauma (n = 25) reported less positive emotion and showed greater SC responses across all threat levels. They also showed threat-dependent elevations in reported negative emotions and EMG responses. Results suggest that childhood trauma may lead to long-lasting alterations in emotional and psychophysiological reactivity even in the absence of current Axis I psychopathology. Keywords: childhood trauma, startle, police stress, psychophysiology Adverse experiences during childhood can have long-lasting effects. For example, childhood trauma is a well-established risk factor for adult psychopathology (Brewin, Andrews, & Valentine, 2000; Kendler, Neale, Kessler, Heath, & Eaves, 1992; Kessler, Davis, & Kendler, 1997). Furthermore, accumulating evidence based on studies of nonhuman animals (Coplan et al., 1998; Hall, Huang, & Fong, 1997; Ladd, Owens, & Nemeroff, 1996; Liu et al., 1997; Meaney et al., 1996; Plotsky & Meaney, 1993; Rosenblum et al., 1994; Rosenblum & Paully, 1984; van Oers, de Kloet, & Levine, 1998), human children (Cicchetti & Rogosch, 2001a, 2001b; DeBellis, Chrousos, et al., 1994; De Bellis, Lefter, Trickett, & Putnam, 1994; Galvin et al., 1995; Hart, Gunnar, & Cicchetti, 1995; Scheeringa, Zeanah, Myers, & Putnam, 2004), and human adults who were exposed to early-life adversities (Heim et al., 2000; Metzger et al., 1999; Orr et al., 1998) suggests that exposure to severe early-life stressors can permanently alter psychobiolog- ical systems involved in subsequent threat appraisal and reactivity. Although one might speculate that observed psychobiological ab- errations among adults exposed to childhood trauma are due to trauma exposure, most human research bearing on this question has examined adults with concurrent Axis I disorders. Thus, it is unclear whether the observed abnormal reactivity to adult stressors is a consequence of early trauma, current psychopathology, or both. We undertook the present study to determine whether childhood trauma history in the absence of current Axis I psychopathology alters adult emotional and psychophysiological reactivity under threat. If so, then individuals with a history of childhood trauma may be more sensitive to later traumatic stress exposure than those without a history of childhood trauma and consequently more vulnerable to developing posttraumatic stress disorder (PTSD), depression, and related psychopathology. Further understanding of the effects of childhood trauma on responses to adult stressors could be important for society as a whole and especially important for subgroups who are at high risk for exposure to adult trauma, such as soldiers, firefighters, and police officers. Previous Studies of the Psychobiology of Childhood Trauma Most of the literature on the psychobiological effects of child- hood trauma has focused on hypothalamic–pituitary–adrenal axis dysfunction, such as hypersecretion of corticotropin-releasing fac- tor, adrenocorticotropic hormone, or cortisol in nonhuman animals or human children (e.g., Ladd et al., 1996; Liu et al., 1997; Plotsky & Meaney, 1993; Putnam & Trickett, 1997). One of the few Nnamdi Pole, Department of Psychology, University of Michigan; Thomas C. Neylan, Christian Otte, Thomas J. Metzler, Suzanne R. Best, Clare Henn-Haase, and Charles R. Marmar, Department of Psychiatry, University of California, San Francisco, and San Francisco VA Medical Center. This project was supported by National Institute of Mental Health Grant R01-MH056350-06 to Charles R. Marmar. We thank all of the police cadets who participated in this research; Scott P. Orr for his consultation on this project; Gary Tarasovsky, Tiffany Jackson, Jennifer Smith, Adia Jackson, and Sabra Inslicht for their assistance in the management and analysis of these data; Lisa Rasco for her helpful comments on a draft of this article; and Delores Carter Pole for her special contributions. Correspondence concerning this article should be addressed to Nnamdi Pole, Department of Psychology, University of Michigan, 2260 East Hall, 530 Church Street, Ann Arbor, MI 48109-1043. E-mail: nnamdi@umich.edu Journal of Abnormal Psychology Copyright 2007 by the American Psychological Association 2007, Vol. 116, No. 2, 352–361 0021-843X/07/$12.00 DOI: 10.1037/0021-843X.116.2.352 352