Journal of Anxiety Disorders

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1 Journal of Anxiety Disorders 25 (2011) Contents lists available at ScienceDirect Journal of Anxiety Disorders Disgust and the development of posttraumatic stress among soldiers deployed to Afghanistan Iris M. Engelhard a,, Bunmi O. Olatunji b, Peter J. de Jong c a Clinical and Health Psychology, Utrecht University, PO Box 80140, 3508TC Utrecht, The Netherlands b Department of Psychology, Vanderbilt University, USA c Department of Clinical and Developmental Psychology, University of Groningen, The Netherlands article info abstract Article history: Received 20 April 2010 Received in revised form 12 July 2010 Accepted 2 August 2010 Keywords: Disgust sensitivity Disgust propensity Anxiety disorders PTSD Trauma Soldiers Longitudinal Horror Although the DSM-IV recognizes that events can traumatize by evoking horror, not just fear, the role of disgust in the development of posttraumatic stress disorder (PTSD) has received little research attention. In a study of soldiers deployed to Afghanistan, we examined whether reports of peritraumatic disgust and trait disgust vulnerability factors (disgust propensity and disgust sensitivity) predict PTSD-symptoms, independently of peritraumatic fear, neuroticism, and anxiety sensitivity. Participants (N = 174) enrolled in this study before deployment, and were retested around 6 months (N = 138; 79%) and, again, 15 months (N = 107; 62%) after returning home. The results showed that (1) greater peritraumatic disgust and fear independently predicted PTSD-symptom severity at 6 months, (2) greater disgust propensity predicted more peritraumatic disgust, but not PTSD-symptom severity, and (3) disgust sensitivity moderated the relationship between peritraumatic disgust and PTSD-symptom severity. Implications of these findings for broadening the affective vulnerabilities that may contribute to PTSD will be discussed Elsevier Ltd. All rights reserved. 1. Introduction A growing literature has implicated disgust in the development of anxiety disorders, including spider phobia, blood-injectioninjury phobia, and contamination-based obsessive compulsive disorder (see Cisler, Olatunji, & Lohr, 2009a; McNally, 2002; Olatunji & McKay, 2007; Rozin, Haidt, & McCauley, 2008). Cognitive (Dalgleish & Power, 2004) and contemporary conditioning (Davey, 1997) theories suggest that disgust may also be relevant in the development of posttraumatic stress disorder (PTSD) by means of the representation of the traumatic event. The association between disgust and PTSD may be understood in conditioning terms (see Engelhard, de Jong, van den Hout, & van Overveld, 2009) where a person learns that previously neutral, conditioned stimuli (CSs), present at the time of the traumatic event (unconditional stimulus; US), are linked to the event. Later exposure to the CS will activate memory representations of the US, which activates associated, conditioned responses (CRs). This may take two forms: signal-learning and evaluative learning (Hermans, Vansteenwegen, Crombez, Baeyens, & Eelen, 2002). Signal-learning refers to learning that the CS is a signal of the re-occurrence of the US (i.e., CS predicts US; e.g., for sexual assault Corresponding author. Tel.: ; fax: address: i.m.engelhard@uu.nl (I.M. Engelhard). victims: If I m alone with a man, then I ll be assaulted ). Extinction of learned fear requires the acquisition of disconfirming information (CS/No-US), so that the CS loses its signaling quality. Evaluative learning involves the process by which an affective evaluative reaction evoked by a US is transferred to a CS (De Houwer, Thomas, & Baeyens, 2001). In the event of evaluative conditioning with a disgusting US, the CS would not become a predictor of the US, but would become intrinsically disgusting (i.e., CS refers to a disgusting US representation; e.g., the smell of aftershave of a perpetrator or the location where a bomb exploded and mutilated a fellow soldier may elicit disgust via activating a disgust-related US representation). Effects of evaluative conditioning are less sensitive to extinction procedures than signal learning (see De Houwer, 2007). Experimental research suggests that disgust responses may be acquired through evaluative learning and evaluative conditioned disgust is often resistant to extinction (Mason & Richardson, 2010; Olatunji, Forsyth, & Cherian, 2007). Signal-learning and evaluative conditioning effects both seem to be relevant for PTSD. First, trauma-related cues may predict US activation, and depending on the type of US representation that is elicited, this may give rise to intense fear, anger, shame, disgust, etc. Second, trauma-related cues may also become intrinsically aversive (e.g., disgusting). Peritraumatic emotions (e.g., disgust) may thus not only be an important source of (current) emotional responses (e.g., fear, disgust), but may also provide important clues regarding the type of US representation elicited by trauma cues (cf /$ see front matter 2010 Elsevier Ltd. All rights reserved. doi: /j.janxdis

2 I.M. Engelhard et al. / Journal of Anxiety Disorders 25 (2011) Huijding & de Jong, 2007). For example, strong (peritraumatic) disgust responses may point to experienced threat of contamination or to being exposed to intense moral transgressions (e.g., Rozin, Haidt, & Fincher, 2009; Rozin, Haidt, & McCauley, 2009). Although the DSM-IV (APA, 1994) recognizes that events can traumatize by evoking peritraumatic horror, not just fear, thus far the role of disgust has received only scant attention in research on PTSD. Preliminary research has shown that reported peritraumatic emotions often include disgust, for example, in witnesses of a catastrophic train crash (Engelhard, van den Hout, Arntz, & McNally, 2002). Likewise, when female sexual assault victims recall the assault memory, they report elevated feelings of disgust (Fairbrother & Rachman, 2004; Feldner, Frala, Badour, Leen- Feldner, & Olatunji, 2010). This also occurs in female students who imagine experiencing a non-consensual kiss (Fairbrother, Newth, & Rachman, 2005), and in women with PTSD during exposure to a variety of traumatic events (Olatunji, Babson, Smith, Feldner, & Connolly, 2009). Furthermore, women with a history of childhood sexual abuse and associated PTSD report significantly more disgust during the recollection and imagery of the event than those without PTSD (Shin et al., 1999). Although these initial findings suggest that disgust may indeed be relevant in the development of PTSD, an important next step would be to test the prognostic value of peritraumatic disgust in a longitudinal design. In addition, it may be helpful to determine whether the relationship between peritraumatic disgust and PTSD symptoms is independent of levels of peritraumatic fear, because disgust and fear are closely related (Woody & Teachman, 2000), and the combination of fear and disgust (horror) may be a common response to trauma (McNally, 2002). Therefore, the first aim of this study was to test the predictive validity of peritraumatic disgust independently of peritraumatic fear. If peritraumatic disgust causally contributes to PTSD, then people with enhanced trait disgust would be especially at risk for developing PTSD symptoms. There is some preliminary evidence that trait disgust vulnerabilities may indeed contribute to PTSD symptoms (Foy, Sipprelle, Rueger, & Carroll, 1984; Herba & Rachman, 2007). Recent research suggests that it is important to distinguish disgust propensity and disgust sensitivity.disgust propensity is the tendency to experience disgust more readily (Van Overveld, de Jong, Peters, Cavanagh, & Davey, 2006). Potential disgust domains include core disgust (related to food, animals, and body products), animal-reminder disgust (death and envelope violations), and contamination disgust (concerns about interpersonal transmission of essences; Haidt, McCauley, & Rozin, 1994, Rozin et al., 2008; Olatunji, Williams, et al., 2007). These domains may be relevant for different types of traumatic events. For instance, animal-reminder disgust may be relevant for exposure to horrific images, while contamination disgust may be relevant for events involving physical contact. Disgust sensitivity is the tendency to find the emotion of disgust unpleasant (Van Overveld et al., 2006). Disgust propensity and disgust sensitivity can reliably be assessed (e.g., Olatunji, Cisler, Deacon, Connolly, & Lohr, 2007; Olatunji, Forsyth, et al., 2007; Van Overveld et al., 2006). Higher levels of disgust propensity are assumed to increase the probability that certain stimuli acquire a disgust-evoking status, whereas higher levels of disgust sensitivity are thought to motivate people to avoid stimuli that will evoke the unpleasant emotion of disgust, thereby maintaining symptoms (Van Overveld, de Jong, & Peters, 2010). Therefore, the second aim of this study was to test whether people higher in disgust propensity report more peritraumatic disgust, and the third aim was to test whether disgust sensitivity moderates the relationship between peritraumatic disgust and PTSD symptoms. More specifically, in a sample of soldiers exposed to horrific events on deployment to Afghanistan, we tested the hypothesis that (1) the intensity of peritraumatic disgust predicts PTSD symptoms, independently of peritraumatic fear, (2) disgust propensity (especially animal-reminder disgust) predicts levels of peritraumatic disgust, thereby predicting PTSD symptoms, and (3) disgust sensitivity moderates the relationship between peritraumatic disgust and PTSD symptoms. Neuroticism and anxiety sensitivity are related to disgust propensity and sensitivity (see Van Overveld et al., 2006), and are known risk factors for PTSD symptom severity (Engelhard, van den Hout, & Lommen, 2009; Taylor, 2003). Indices of neuroticism and anxiety sensitivity were included to examine whether the relationships between disgust propensity/sensitivity and PTSD symptom severity are independent of these variables. Given that evaluative conditioning effects may be involved in disgust-related problems, we also explored whether peritraumatic disgust and disgust propensity predict negative evaluative ratings (hedonic shifts) of deployment-related stimuli, including deployment itself, colleagues, and local people. Moreover, based on the observation (Olatunji, Lohr, Smits, Sawchuk, & Patten, 2009) that disgust sensitivity may enhance disgust-relevant learning (the more aversive the experience of disgust, the stronger the impact of disgust on evaluative conditioning effects), we also explored whether disgust sensitivity moderates the link between peritraumatic disgust and negative evaluative changes. 2. Material and methods 2.1. Participants and procedure About 6 8 weeks before deployment, 176 infantry soldiers from the Royal Netherlands Army were invited to participate in this study. They were from two Air Assault Brigades that deployed to Afganistan s southern province Uruzgan for about 4 months in 2006 or The operation Task Force Uruzgan was part of the NATO s International Security Assistance Force in Afghanistan. Their main duties were to improve security and support reconstruction. At several sites, troops available during their preparation program were told about this study by their commanding officers. They met the principal investigator (IME) or research assistant several days later, who gave complete information about the study. Participation was voluntary without financial compensation. Two soldiers refused, and 174 soldiers agreed to participate. Their mean age was 24 (SD = 4.9). About 27% was married or cohabiting, 33% had a partner, and the others were single. Most had finished high school, and 5% was college-educated. About 35% had no prior deployment, 43% had one, and 22% had at least two. Before deployment, several measures were administered, including questionnaires about demographic and military characteristics, neuroticism, and PTSD symptoms. This sample sustained two fatal casualties on deployment, including one participant. About 6 months after returning home, 138 participants (79%) were retested using questionnaires about potentially traumatizing events, trauma-related emotions, disgust propensity, disgust sensitivity, and PTSD symptoms, and 134 participants completed a clinical interview to index PTSD diagnosis. About 15 months after returning home, 107 participants (62%) completed questionnaires measuring PTSD symptoms and negative evaluative changes in deployment-related stimuli. Considerable effort was put into contacting and retesting participants to limit potential bias from dropout. The reasons for attrition included being on leave, attending a course, or being posted to new units. The institutional review board of Maastricht University/Academic Hospital Maastricht approved this study Measures The Eysenck Personality Questionnaire (EPQ; Eysenck & Eysenck, 1975; Sanderman, Arrindell, Ranchor, Eysenck, & Eysenck,

3 60 I.M. Engelhard et al. / Journal of Anxiety Disorders 25 (2011) ) was used to measure neuroticism (range 0 22). The EPQ has been shown to have good psychometric properties (Sanderman et al., 1995). The Potentially Traumatizing Events Scale (PTES; Maguen, Litz, Wang, & Cook, 2004; see also Engelhard & van den Hout, 2007) included 22 war zone stressors (e.g., going on patrols, disarming civilians, being shot at). Participants rated whether they had experienced each event in Afghanistan. The number of experienced events was calculated (range 0 22). 1 Participants were asked to describe their most negative experience on deployment, using an open-ended question, and to rate the severity of their emotions at the time of the event, including fear and disgust, 2 using a 4-point scale (0 = not at all, 3 = very much). Then they were asked to complete the PTSD Symptom Scale (PSS; Foa, Riggs, Dancu, & Rothbaum, 1993; Engelhard, Arntz, & van den Hout, 2007) with reference to this event. The PSS was used to measure PTSD symptom severity. The 17 items correspond to the DSM-IV symptoms (5 reexperiencing, 7 avoidance/numbing, and 5 hyperarousal), and were rated on 4-point scales (0 = not at all, 3 = almost always) for the past month. The PSS has good reliability and concurrent validity (Foa et al., 1993; Engelhard, Arntz, et al., 2007; Engelhard, van den Hout, Arntz, et al., 2007; =.84 in this study). The Disgust Scale-R (DS-R; Haidt et al. 1994; modified by Olatunji, Williams, et al., 2007; Van Overveld, 2008) measures disgust propensity, and consists of 25 items that measure core disgust (12 items), animal-reminder disgust (8 items), and contamination disgust (5 items). Items were scored on 5-point scale (0 4), with higher scores indicating more disgust propensity. The average score per subscale was computed. Cronbach s was.70,.67, and.28, respectively, for the three subscales in this study. The reliability of the contamination subscale was insufficient, so findings related to this scale should be interpreted with caution. The Disgust Propensity and Sensitivity Scale-revised (DPSS-R; Van Overveld et al., 2006) consists of 16 items that are rated on a 1 (never) to 5 (always) scale. The scale is internally consistent (Van Overveld et al., 2006) and has shown predictive validity for experienced disgust in disgust-eliciting experimental tasks across all relevant domains (Van Overveld et al., 2010). The disgust sensitivity subscale (7 items) was used in the analyses ( =.84 in this study). The Anxiety Sensitivity Index-3 (Taylor et al., 2007) is an 18- item measure that assesses cognitive, social, and physical concerns about arousal-related sensations. The ASI-3 has shown good reliability and validity (Taylor et al., 2007; =.73 in this study). The Clinician Administered PTSD Scale (CAPS; Blake et al., 1995) was used to assess current clinician-rated PTSD symptom severity. The CAPS is a widely used, semi-structured clinical interview that measures the frequency and intensity of each of the 17 PTSD symptoms, as outlined in DSM-4, on 5 point (0 4) rating scales. These ratings are summed to create a total score ranging from 0 to 136 (Weathers, Keane, & Davidson, 2001). Negative changes in evaluations of deployment-related stimuli were assessed by asking participants to indicate whether their evaluation of deployment itself, their colleagues on deployment, and local people in Afghanistan had become more negative (1), remained the same (2), or had become more positive (3). The scores of this continuous variable were mirrored to index negative evaluative changes after deployment. 1 Participants also rated the negative impact of each experienced event. Since this severity index was strongly related to the number of events (r =.67), only the latter will be reported. 2 The word revulsion was used, because disgust is linked to food and eating (Rozin, Haidt, & McCauley, 2009). 3. Results 3.1. Participant and trauma characteristics Participants not retested at 6 months (n = 35) were older (M = 25.9) than those retested (n = 138; M = 23.5), F(1, 171) = 7.63, p <.05. There were no significant group differences regarding education, prior deployments, neuroticism, and pre-deployment PSS scores. Participants not tested at 15 months (n = 66) had less prior deployments, F(1, 171) = 4.28, p =.04, and tended to show higher disgust contamination scores, F(1, 135) = 3.76, p =.06, than those retested (n = 107). There were no other significant group differences. The average number of events on the PTES experienced in Afghanistan was 14.7 (SD = 3.6; range 4 22). The most common events included: being told that a colleague got killed (97%), witnessing an explosion (87%), being shot at (86%), seeing dead or injured civilians (81%), disarming civilians (78%), locating an explosive device (71%), and seeing dead or injured soldiers (58%). About 14% of participants reported some or (very) much peritraumatic disgust during their most negative event. Most of these disgustevoking events involved exposure to death or severe injury of a colleague or civilian, while some involved moral disgust (conflicts about roles and duties, partner s infidelity). Table 1 shows descriptive statistics and correlations of the main study measures. PSS scores were generally low after deployment. Based on the CAPS at 6 months, 2 participants (2%) had PTSD after deployment, and 7 participants (5%) had partial PTSD (i.e., meeting the DSM-IV criteria for PTSD, except for the avoidance/numbing cluster). PSS, peritraumatic fear, peritraumatic disgust, and ASI scores exhibited significant skew to the right and were transformed with a square root function to satisfy assumptions of normality Disgust variables and PTSD symptoms First, we examined whether peritraumatic disgust and fear were independently associated with PTSD symptom severity (PSS) at 6 months. Table 1 shows that the correlations between these three variables were significant. A multiple regression analysis revealed that peritraumatic disgust (ˇ =.17, t = 1.92, p =.057) and fear (ˇ =.22, t = 2.48, p <.05) independently predicted PSS scores, F(2, 15) = 6.28; p <.05; R 2 = Second, we examined whether disgust propensity was associated with peritraumatic disgust levels. Table 1 shows that peritraumatic disgust was significantly correlated with animal-reminder disgust (DS-R), but not with core disgust and contamination disgust (DS-R). Peritraumatic disgust was also related to neuroticism (EPQ- N), anxiety sensitivity (ASI-3) and disgust sensitivity (DPSS-R). A regression analysis showed that DS-R animal-reminder disgust (ˇ =.26, t = 2.30, p <.05) and EPQ-N (ˇ =.24, t = 2.81, p <.05) independently predicted peritraumatic disgust, F(2, 123) = 10.43; p <.05; R 2 = 0.15, while ASI-3 and DPSS-R were no longer significant (largest ˇ =.11, p >.05). Disgust propensity (DS-R subscales) was not significantly correlated with PSS scores at 6 months. However, PSS scores were significantly correlated with disgust sensitivity (DPSS-R sensitivity scale), EPQ-N and ASI-3 (particularly mental concerns). A regression analysis showed that EPQ-N (ˇ =.39, t = 4.95, p <.05) remained a significant predictor of PSS scores, F(1, 134) = 24.54; p <.05; R 2 = 0.16, while the DPSS-R and ASI-3 were no longer significant (largest ˇ =.13, p >.05). None of the disgust-related variables were significantly correlated with PSS scores at 15 months. Third, to examine whether disgust sensitivity moderated the relationship between peritraumatic disgust and PTSD symptoms, we conducted a linear regression analysis, and entered peritraumatic disgust, disgust sensitivity, and their interaction (created by

4 I.M. Engelhard et al. / Journal of Anxiety Disorders 25 (2011) Table 1 Descriptive statistics and Pearson correlations for study measures. M (SD) a 5b 5c 6 7 Pre-deployment 1. EPQ-N 2.71 (3.20) 6 months post-deployment 2. Peritraumatic disgust 0.44 (0.90).28 * 3. Peritraumatic fear 0.54 (0.80) a.22 *.22 * 4. ASI (3.78) a.26 *.23 *.24 * 5a. DS-R core 1.01 (0.51) *.25 * b. DS-R animal-reminder 1.01 (0.60).20 *.27 *.22 *.29 *.61 * c. DS-R contamination 0.47 (0.46).20 * *.47 *.42 * 6. DPSS-R sensitivity 9.86 (2.76).36 *.24 *.18 *.47 *.38 *.39 * 7. PSS 2.81 (3.76) a.39 *.22 *.26 *.19 * * 15 months post-deployment 8. PSS 3.25 (4.80) a.36 * * Note: EPQ-N = Eysenck Personality Scale-Neuroticism scale, ASI-3 = Anxiety Sensitivity Index 3; DS-R = Disgust Scale-Revised; DPSS-R = Disgust Propensity and Sensitivity Scale-Revised Sensitivity Subscale; PSS = PTSD Symptom Scale; NC = Negative evaluative changes. According to Cohen (1992), values of.1 represent a small effect,.3 is a medium effect, and.5 is a large effect. a Untransformed scores. * p <.05 (2-tailed). z-scores). A significant model was found, R 2 =.08, F(3, 118) = 3.42, p =.02, with a significant interaction between peritraumatic disgust and disgust sensitivity (ˇ =.20, t = 1.95, p =.05), such that greater scores predicted more PTSD symptoms. Thus, the effect of peritraumatic disgust on PTSD symptoms was moderated by disgust sensitivity. Finally, we explored whether disgust-related factors were associated with negative evaluative ratings of deployment-related stimuli at 15 months. Greater peritraumatic disgust was associated with more negative evaluative changes about local people in Afghanistan (r =.21, p <.05), which was not the case for peritraumatic fear (r =.11, p >.05). Disgust sensitivity did not moderate the link between disgust and evaluative changes: a linear regression model to predict negative evaluative changes by peritraumatic disgust, disgust sensitivity, and their interaction (created by z-scores) was not significant, R 2 =.07, F(3, 82) = 1.99, p =.12, and included a non-significant interaction term, ˇ =.15, t = 1.29, p =.20. Finally, DS- R core disgust was associated with negative evaluation changes about deployment itself (r =.21, p <.05) and colleagues on deployment (r =.29, p <.05). 4. Discussion This study examined whether peritraumatic disgust and disgust-related vulnerability are associated with posttraumatic stress in a sample of soldiers exposed to aversive events on deployment to Afghanistan. All participants were exposed to potentially traumatizing war zone events, such as seeing dead or wounded people, being shot at, and witnessing an explosion. Events that elicited disgust typically involved seeing death or injury. The main findings can be summarized as follows: (1) greater peritraumatic disgust and fear levels were independent predictors of PTSD symptom severity at 6 months, (2) greater disgust propensity in the animal-reminder domain predicted more peritraumatic disgust, even after controlling for neuroticism, but did not predict PTSD symptom severity, and (3) disgust sensitivity moderated the link between peritraumatic disgust and PTSD symptom severity. In addition, our exploratory analyses showed that peritraumatic disgust and disgust propensity predicted more negative evaluative changes (hedonic shifts) in deployment-related stimuli. Soldiers who reported more intense disgust at the time of their most stressful experience on deployment exhibited more severe PTSD symptoms, and this relationship was maintained after statistically controlling for the influence of peritraumatic fear. This finding suggests that disgust responses to a traumatic event may be relevant in the development of PTSD symptoms, independent of fear responses. Peritraumatic fear and disgust reactions may reflect the nature of the cognitive representation of the US. The US representation may involve both danger and aversion-related elements (e.g., vivid images of death, decay, and injuries) that are elicited by trauma-related cues and give rise to (current) emotional responses. If the finding that people with greater peritraumatic disgust develop more severe PTSD symptoms independent of peritraumatic fear is replicated, clearly delineating the differences in the acquisition and maintenance of these two trauma-related emotions will be an important direction for future research. Signallearning has been a prominent explanation for fear acquisition, but evaluative conditioning may be a more useful mechanism for understanding acquired disgust responses (Woody & Teachman, 2000). An examination of differences in learning mechanisms of fear and disgust in PTSD may increase the understanding of the origins of PTSD, and may also facilitate the identification of novel treatment approaches. Effective treatments for PTSD use exposure techniques that confront patients with CSs to teach them that these no longer predict the US. However, patients may show less or insufficient benefit from exposure treatments when fear is not the primary emotion (e.g., Rothbaum, Meadows, & Resick, 2000). Relatively insufficient effects of exposure therapy may result partly from the fact that exposure targets fear acquired through signal-learning, while patients may show signs of evaluative (disgust) conditioning effects, like feeling dirty despite excessive washing after sexual assault (Fairbrother & Rachman, 2004) or after contact with corpses during combat (Pitman, 1993). Laboratory studies suggest that evaluative conditioning effects are relatively resistant to extinction (De Houwer et al., 2001), but may be altered by other interventions such as counterconditioning or US revaluation techniques (Baeyens, Eelen, van den Bergh, & Crombez, 1989). If this form of learning is involved in PTSD, another important direction for future clinical research is to identify new techniques that successfully target evaluative conditioning effects, and optimize treatment for PTSD. Examination of disgust-related vulnerabilities revealed that soldiers higher in trait disgust propensity (in the animalreminder domain) did not report more PTSD symptoms, but did report stronger peritraumatic disgust responses. This relationship remained intact even after controlling for neuroticism. This finding supports the relevance of trait disgust as a factor that may moderate the evaluation of potentially traumatic events. The animal-reminder domain may be specifically relevant to the type of events many soldiers were exposed to, involv-

5 62 I.M. Engelhard et al. / Journal of Anxiety Disorders 25 (2011) ing images of death and body envelope violations. Other disgust domains might be more relevant for other types of traumatic events. For example, a recent study found that contact contamination concerns predict feelings of dirtiness among women who imagine experiencing an unwanted kiss (Herba & Rachman, 2007). Although our findings are silent with respect to causality, they are consistent with the hypothesis that disgust propensity may contribute to disgust responses to traumatic events. However, the absence of a relation between disgust propensity and PTSD symptoms (and the hypothesized mediational effect of peritraumatic disgust) was inconsistent with the expectations. The present study also found that the association between peritraumatic disgust and PTSD symptoms was moderated by disgust sensitivity, such that higher levels of peritraumatic disgust and disgust sensitivity were associated with increased PTSD symptoms. This finding suggests that disgust sensitivity may be a potential mechanism that strengthens the influence of experiencing disgust on PTSD symptoms, and contributes to recent work focusing on other anxiety disorders that showed a similar moderating effect of disgust sensitivity (Cisler, Olatunji, & Lohr, 2009b). Most important for the present context, if the cognitive US representation in PTSD involves more (peritraumatic) disgust and this emotion is appraised as aversive, this may motivate cognitive and behavioral avoidance of corresponding trauma-related stimuli, which may render PTSD symptoms self-perpetuating. The exploratory analyses showed that disgust sensitivity did not moderate the relationship between peritraumatic disgust and negative evaluative changes. This may be partly due to a power problem resulting from the small sample size 15 months after deployment. This study highlights the importance of disgust-related experiences in posttraumatic stress among soldiers, but it should be noted that associations among variables were modest, which limits the applied utility of the findings. In addition, several limitations should be noted. First, PTSD symptom levels were low, which is consistent with earlier research of Dutch soldiers deployed to Iraq (Engelhard, van den Hout, Arntz, et al., 2007). Low symptom levels leave little room in variance for delineating potential causal factors. Second, participants were male soldiers previously screened for good health. This may limit the generalizability of the findings. Third, limitations may be imposed by the retrospective assessment of trauma-related variables, which is prone to distortion (Engelhard, van den Hout, & McNally, 2008). Fourth, disgust propensity and sensitivity were measured after deployment. The extent to which traumatization may have affected disgust vulnerability is unknown. Research has shown that anxiety sensitivity and PTSD symptom severity are reciprocally related, such that anxiety sensitivity predicts later PTSD symptom severity, and symptom severity predicts later anxiety sensitivity (Marshall, Miles, & Stewart, 2010). Disgust sensitivity may be similarly prone to change across time. Lastly, this investigation relied mainly on self-report questionnaires. A multimodal assessment approach may allow for more definitive inferences to be made (see Cisler et al., 2009a). Despite these limitations, this study does extend previous findings regarding the role of disgust in PTSD to soldiers. Prior research has focused almost exclusively on sexual assault of women. The present findings suggest that initial disgust reactions to a traumatic event are associated with posttraumatic stress in soldiers and that the link between peritraumatic disgust and PTSD symptoms is moderated by disgust sensitivity. In addition to addressing limitations of the present study, and the directions for future research given earlier, future research is also needed to elucidate the causal direction and underlying mechanisms of the disgust-ptsd association. Acknowledgments Supported by the Netherlands Organization for Scientific Research (NWO) with a Veni and Vidi Innovational Research grant and by the Veterans Institute (Doorn, The Netherlands) with a grant to the first author. Presented at the 43rd annual convention of the Association for Behavioral and Cognitive Therapies (New York City, November, 2009). 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