Predictors of Posttraumatic Stress Disorder Among Police Officers:A Prospective Study

André MarchandUniversité du Québec a Montréal and Centre de Recherche del’Institut Universitaire en santé mentale de Montréal, Montréal,

Québec, Canada

Céline Nadeau and Dominic Beaulieu-PrévostUniversité du Québec a Montréal

Richard BoyerCentre de Recherche de l’Institut Universitaire en santé mentale

de Montréal, Montréal, Québec, Canada

Mélissa MartinUniversité du Québec a Montréal

This prospective study examined risk and protective factors in the development of posttraumatic stressdisorder (PTSD) in a sample of 83 police officers. Structured interviews were conducted in order toassess the most recent work-related traumatic event and establish diagnoses of acute stress disorder(ASD) and full or partial PTSD. Police officers were assessed between 5 and 15 days, and at 1 month,3 months, and 12 months after the event. They also completed self-administered questionnaires assessingseveral potential predictors. Predictive analyses about the onset of PTSD were based on a 4-step nestedrandom-effect linear regression. Overall, results showed that the modulation of PTSD symptomatologywas associated with some pretraumatic (i.e., emotional coping strategies and number of children),peritraumatic (i.e., physical and emotional reactions and dissociation), and posttraumatic factors (i.e.,ASD, depression symptoms, and seeking psychological help at the employee assistance program and atthe police union between the event and Time 1). Clinical implications of these findings are discussed andkey directions for future studies are proposed.

Keywords: posttraumatic stress disorder (PTSD), police, risk factor, protective factor, prospective study

Supplemental materials: http://dx.doi.org/10.1037/a0038780.supp

Due to the nature of their work, police officers encounter fre-quent exposure to unpredictable incidents that pose a threat to theirlife or their physical integrity (e.g., road accidents, gunfire, sui-cides, and homicides). These potentially traumatic events cangenerate major repercussions on their psychosocial and occupa-tional functioning. They can even lead to the development of acutestress disorder (ASD) or posttraumatic stress disorder (PTSD;Carlier, 1999; McNally & Solomon, 1999). However, not allpolice officers exposed to traumatic events will subsequently de-

velop ASD or PTSD (King, Vogt, & King, 2004). Studies haveidentified a series of risk and protective factors involved in themodulation of posttraumatic reactions. These can be classified intothree categories: pretraumatic, peritraumatic, and posttraumatic.Martin, Germain, and Marchand (2006) offer a detailed review ofsuch factors, but only an overview of the main findings with policeofficers is presented here.

Pretraumatic Predictors

Studies among police officers have identified several pretrau-matic predictors of PTSD. In summary, recent investigations havefound that cumulative exposure to duty-related critical incidents,occupational stressors, and a greater exposure to traumatic eventsat work during the past year predispose to the development ofposttraumatic reactions (Friedman & Higson-Smith, 2003; Liber-man et al., 2002; Violanti & Gehrke, 2004). Other studies haverevealed that limited work experience increased the likelihood ofdeveloping PTSD for junior police officers (Hodgins, Creamer, &Bell, 2001; Marmar et al., 2006). The impact of past personaltraumas also appears to be a significant predictor (Gehrke &Violanti, 2004; Pole, 2008). Moreover, the presence of familypsychiatric history (i.e., mood, anxiety and substance abuse disor-ders) was identified as a vulnerability factor for experiencinggreater peritraumatic distress to critical incident exposure, which,

This article was published Online First March 16, 2015.André Marchand, Department of Psychology, Université du Québec a

Montréal, and Centre de Recherche de l’Institut Universitaire en santémentale de Montréal, Montréal, Québec, Canada; Céline Nadeau, Depart-ment of Psychology, Université du Québec a Montréal; Dominic Beaulieu-Prévost, Department of Sexology, Université du Québec a Montréal; Rich-ard Boyer, Centre de Recherche de l’Institut Universitaire en santé mentalede Montréal; Mélissa Martin, Department of Psychology, Université duQuébec a Montréal.

This research was supported by grants from Institut de recherche Robert-Sauvé en santé et en sécurité du travail.

Correspondence concerning this article should be addressed to AndréMarchand, Department of Psychology, Université du Québec a Montréal,P. O. Box 8888, Succ. Centre-Ville, Montréal (Québec), H3C 3P8 Canada.E-mail: marchand.andre@uqam.ca

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Psychological Trauma: Theory, Research, Practice, and Policy © 2015 American Psychological Association2015, Vol. 7, No. 3, 212–221 1942-9681/15/$12.00 http://dx.doi.org/10.1037/a0038780

212

in turn, increased the risk of developing PTSD (Inslicht et al.,2010). Women police officers seem to have the same risk ofdeveloping PTSD after a traumatic event than their male counter-parts (Darensburg et al., 2006; Pole et al., 2001). Neurotic person-ality as well as trait dissociation are associated with greater PTSDsymptoms among police officers (Haisch & Meyers, 2004; Mar-mar et al., 2006; McCaslin et al., 2008). Those who have difficul-ties in expressing their emotions are more likely to develop post-traumatic reactions (Carlier, Lamberts, & Gersons, 1997; Meffertet al., 2008). The tendency to fear anxiety-related symptoms is alsoa risk factor for PTSD (Asmundson & Stapleton, 2008). Lastly,hypersensitivity to threat and a slower habituation process werefound to prospectively predict PTSD symptom severity in policerecruits (Pole et al., 2009).

Prior experience of successful field operation and adequatetraining to react to stressful situations were reported by somestudies as preventing posttraumatic reactions (Marmar et al., 2006;Perrin et al., 2007), but were not confirmed by others (Alexander& Wells, 1991; Carlier et al., 1997). Furthermore, personalityhardiness was found to be negatively associated with PTSD symp-toms in female police officers (Andrew et al., 2008; Martin,Marchand, Boyer, & Martin, 2009). As for coping strategies,results remain unclear as to whether emotion- or problem-focusedcoping strategies are beneficial for police officers (LeBlanc, Re-gehr, Jelley, & Barath, 2008; Marmar et al., 2006).

Peritraumatic Predictors

Peritraumatic experiences such as dissociation, physical andemotional reactions during trauma, a threat to one’s partner’s lifeor physical integrity, severity of exposure, as well as exposure todeath constitute risk factors in the development of PTSD amongpolice officers (Hodgins et al., 2001; Inslicht et al., 2010; Marmaret al., 2006; Martin et al., 2009; McCaslin et al., 2006, 2008; Perrinet al., 2007; Pole et al., 2001). In addition, one study has found thatpolice officers carrying out unusual tasks during a critical event(e.g., rescuing or recovering work at the World Trade Center sites,working outside one’s area of expertise, working for prolongedtime) were more at risk of developing PTSD (Perrin et al., 2007).The only study, to our knowledge, that assessed peritraumaticprotective factors reported that police officers who received sup-port from their colleagues during or immediately after a traumaticevent developed less PTSD symptoms (Martin et al., 2009).

Posttraumatic Predictors

Studies have outlined several posttraumatic factors that predictPTSD among police officers, such as short periods of time allo-cated by the employer to recover from the event, dissatisfactionwith organizational support, or lack of social support outside ofpolice work (Carlier et al., 1997). Incident-related physical inju-ries, depressive symptoms, as well as subsequent negative lifeevents have also been identified as risk factors (Asmundson &Stapleton, 2008; Maguen et al., 2009). Many studies have shownthat using avoidance-based strategies to cope with traumatic eventsis related to greater posttraumatic symptoms (Haisch & Meyers,2004; LeBlanc et al., 2008; Marmar et al., 2006). Furthermore,psychological debriefing was found either to have no impact(Stephens, 1997) or to increase PTSD symptoms (Carlier, Lam-

berts, Van Uchelen, & Gersons, 1998; Carlier, Voerman, & Ger-sons, 2000).

For police officers, higher perceived availability of social sup-port (Friedman & Higson-Smith, 2003; McCaslin et al., 2006) andgreater satisfaction with the support received (Wilson, Poola, &Trew, 1997) have been associated with lower posttraumatic symp-tomatology. A positive attitude from coworkers and supervisorsabout expressing emotions, and ease in talking about trauma atwork, were also associated with fewer PTSD symptoms (Stephens& Long, 2000). A sense of coherence is linked to reduced PTSDsymptomatology as well (Friedman & Higson-Smith, 2003).

To sum up, a significant amount of work has been done in thefield of police psychological trauma, but some findings have beeninconclusive. There is currently no consensus about the signifi-cance and predictive power of certain factors that influence PTSDsymptoms. These ambiguous findings can be explained by themany methodological shortcomings in PTSD research, such as thelack of rigor in many studies, the presence of confounding vari-ables, and the retrospective aspect of most studies. All theseproblems significantly limit the interpretation of the associationsbetween predictors and PTSD. In addition, the number of studieson this topic is limited and many aspects have yet to be explored.

Objectives

The first purpose of this research project aims to address thelack of prospective studies in the police environment and theexistence of methodological shortcomings in the current literature.The second purpose is to expand our knowledge about the predic-tors of PTSD among police officers. The main objective was toidentify the predictors of the development of PTSD following awork-related traumatic event among police officers using a longi-tudinal design. More specifically, this study assessed the riskfactors that increase police officers’ vulnerability to developingPTSD, as well as the protective factors that help them cope after atraumatic event.

Method

Participants and Procedure

The main inclusion criterion to participate in this study washaving recently been exposed to a traumatic event as defined byCriteria A for PTSD in the fourth edition of the Diagnostic andStatistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR; American Psychiatric Association, 2000). Exclusion crite-ria were being in a psychotic state, having an organic mentaldisorder, and having suicidal ideation. Written informed consentwas obtained from all participants, and an institutional reviewboard approved the study.

Eighty-nine participants were initially contacted. Six were ex-cluded after the initial assessment because they did not meet theinclusion criteria. Eighty-three participants took part in the study(i.e., 63 men and 20 women). Two of them withdrew from thestudy at 3 months (Time 3 [T3]), and five did so at 12 months(Time 4 [T4]; e.g., moved, lack of time, or loss of interest). All ofthe participants were active police officers from the police serviceof a major Canadian city with a mean of 8.6 years (SD � 7.3) ofexperience within the police service. They had a mean age of 33

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213PREDICTORS OF PTSD IN POLICE OFFICERS

years (SD � 7.7), an average of 16 years of education (SD � 1.9),and 54% were married or in a relationship (see Table 1).

Police officers were informed of the study through articlespublished in police union and police department newsletters. Theproject was also presented on numerous occasions to senior man-agers of various divisions of the police department—to the policeemployee assistance program’s officials and the labor managementjoint committee, which is composed of representatives of the unionand of the organization. Overall, most referrals came from policeofficers themselves (e.g., participants, supervisors, lieutenants, andcommanders), from the corporate operations division, and from theEAP.

Potential participants were first screened over the phone andthen assessed in person by a trained research assistant using aclinical standardized interview at the police station at four points intime: 5 to 15 days (M � 14.7, SD � 5.9) after the traumatic event(Time 1 [T1]), and 1 month (Time 2 [T2]), 3 months (T3), and 12months (T4) following the event. Participants also filled out ques-tionnaires after each interview.

Type of Trauma

The traumatic events experienced by participants were catego-rized as shootings (40%), riots (14%), family drama involvingdeath or serious injuries of children (14%), car chases (10%),deadly road accidents (4%), and other (18%). The emotion re-ported most frequently by participants concerning the event washelplessness (80%), followed by intense fear (59%) and horror(21%).

Measures

Measures are presented sequentially for outcomes, pretraumaticfactors, peritraumatic factors, and early posttraumatic factors (5 to

15 days after the event). The French versions of the questionnaireswere used and all of them presented good psychometric properties.

Outcomes. The presence or absence of PTSD was assessed atT2, T3, and T4 with the Structured Clinical Interview for DSM–IVAxis I Disorders (SCID-I; First, Spitzer, Gibbon, & Williams,1996). Most studies about the psychometric properties of theSCID-I were conducted using the previous version (SCID-I, DSM–III–R; American Psychiatric Association, 1987). Nonetheless, theproperties of the older version also apply to the current one(SCID-I, DSM–IV–TR; American Psychiatric Association, 2000),as the modules are virtually identical (Roger, 2001). The earlierversion had good concomitant validity with clinician judgment(� � 0.69; Hovens et al., 1992), as well as good convergentvalidity with other PTSD measurements, such as the Impact ofEvent Scale (Solomon et al., 1993). For interrater reliability, kappavalues of 0.87 (Kulka et al., 1990) and 0.77 (Skre, Onstad, Torg-ersen, & Kringlen, 1991) have been reported. The few studies thathave been done with the current version of the SCID-I havereported reliability coefficients comparable with, if not greaterthan, those of the earlier version (Roger, 2001). A diagnosis ofpartial PTSD was assigned when a participant did not have enoughsymptoms to qualify for full PTSD (i.e., had at least one CriterionB, C, and D symptom or at least one Criterion B and two CriterionD symptoms; Schnurr, Lunney, & Sengupta, 2004).

In addition, the intensity of PTSD symptoms was assessed withthe total score of the Modified PTSD Symptom Scale (MPSS-SR;Falsetti, Resnick, Resick, & Kilpatrick, 1993), a 17-item self-report questionnaire measuring the frequency and severity of post-traumatic symptoms in the last 2 weeks. Scores range from 0 to102. The English version had an internal consistency of 0.91,specificity of 83.8%, and concurrent validity of 0.92 with theSCID. The French version was validated in Quebec with a clinicalsample (Guay, Marchand, Iucci, & Martin, 2002), and possessedexcellent internal consistency (Cronbach’s � � .92) and temporalstability (r � .98). The internal consistency in this study wasexcellent (Cronbach’s � � .96).

Pretraumatic factors. Five categories of pretraumatic factorswere assessed: sociodemographic characteristics, work-related in-formation, trauma history, mental health, and psychological traits(i.e., coping strategies, self-efficacy, and psychological hardiness).

A questionnaire was created by the current research team togather information about sociodemographic characteristics (age,gender, education, marital status, number of children, and ethnicbackground) and work-related variables (job position, weeklyhours worked, day/night shifts, and years of experience).

Trauma history was assessed by counting the number of trau-matic events reported on the Life Event Checklist of the Clinician-Administered PTSD Scale (Blake et al., 1995). The checklistassesses exposure to 16 events known to potentially result inPTSD, and has an additional open-ended item allowing for theaddition of any unlisted event. The French version of the ques-tionnaire was validated with Quebec students (Blake et al., 1995).The checklist had good test–retest reliability (r � .97). Internalconsistency was not assessed for this variable because it is notconsidered a relevant characteristic for life events scales.

Mental health was assessed by counting the number of psychi-atric disorders identified in the SCID-I interview. The participantswere also asked whether or not they consulted a medical orparamedical professional in the last 3 months.

Table 1Sociodemographic Characteristics of Police Officers Exposed toa Traumatic Event (n � 83)

Sociodemographic data % M (SD)

GenderMale 76Female 24

Age at time of study 32.6 (7.7)Marital status

Single 39In a relationship 54Separated or divorced 7

Number of childrenOne 11Two 19Three or more 11

Number of years of education 15.6 (1.9)Ethnic origin

Caucasian 92Ethnic minority 8

Afro-Canadian 5Asian 2Hispanic 1

Number of years of experience 8.6 (7.3)Number of hours worked per week 35.4 (3.2)

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214 MARCHAND ET AL.

Coping strategies were assessed with the Coping Inventory forStressful Situations (CISS; Endler & Parker, 1990), a 48-itemself-report inventory measuring task, emotion-, and avoidance-oriented components of coping (16 items/component). A study ofthe French version of the CISS has shown that the three subscalesare relatively independent constructs and that each subscale had agood internal consistency, with Cronbach’s alphas between 0.83and 0.87 (Rolland, 1994). Each subscale is rated from 16 to 80.The internal consistencies in this study were excellent (Cronbach’s� between 0.89 and 0.92).

Self-efficacy was assessed with the Self-Efficacy Scale (Shereret al., 1982), a self-report measure designed to assess feelings ofself-efficacy related to specific situations or behaviors. Its 23 itemscan be divided into two distinct subscales: general (17 items) andsocial (six items). The instrument had good internal consistency,with a Cronbach’s alpha of 0.86 for the general subscale, and 0.71for the social subscale. No test–retest reliability was reported. Theinternal consistency in this study was good for the general subscale(Cronbach’s � � .74) and poor for the social subscale (Cronbach’s� � .49).

Psychological hardiness was assessed with the Short HardinessScale (Bartone, 1995), a 15-item questionnaire that measures threedimensions of psychological hardiness: commitment, control, andchallenge. The French version was validated with adults fromQuebec (Dufour-Pineault, 1997). The Cronbach’s alpha was 0.66for the overall assessment, whereas the corresponding coefficientsfor the commitment, control and challenge subscales were 0.48,0.48, and 0.69, respectively. Test–retest reliability was 0.71. Theinternal consistencies in this study were 0.65, 0.55, and 0.64,respectively.

Peritraumatic factors. Three categories of peritraumatic fac-tors were assessed: duration (self-reported time in minutes),trauma severity, and peritraumatic reactions (i.e., dissociative ex-periences, emotional reactions and physical reactions).

Trauma severity was assessed with the Trauma Severity Ques-tionnaire, which measures, with 24 items, the objective and sub-jective dimensions of the traumatic event, such as the nature andduration of the event, the uncontrollable character of the event, andmore (Martin, Marchand, & Boyer, 2003). This is a specificquestionnaire developed by the current research team. No valida-tion has been carried out.

Dissociative experiences were assessed with the self-report ver-sion of the Peritraumatic Dissociative Experiences Questionnaire(PDEQ; Marmar, Weiss, & Metzler, 1997), a 10-item measure ofdissociative reactions at the time of trauma, including confusion,depersonalization, derealization, time distortion, and out-of-bodyexperience. The instrument has good reliability and validity coef-ficients (Tichenor, Marmar, Weiss, Metzler, & Ronfeldt, 1996). Italso has good convergent, discriminant, and predictive validity(Marmar et al., 1994). The French version of the questionnairewas validated with a student population (Martin & Marchand,2000) and showed psychometric properties equivalent to theEnglish version (Cronbach’s � of 0.85 and test–retest reliabilityof 0.88). The internal consistency in this study was good(Cronbach’s � � .86).

Emotional and physical reactions were assessed with the emo-tional and physical subscales of the Initial Subjective Reaction(ISR) Scale of the Potential Stressful Events Interview (Falsetti,Resnick, Kilpatrick, & Freedy, 1994). The emotional subscale

(ISR-E) uses 15 items, with a 4-point Likert scale, to measure theintensity of various emotional reactions to the event (e.g., fear,confusion, sadness, shame, surprise, anger). Scores range from 15to 60. The physical subscale (ISR-P) uses 10 items to measure theintensity of various reactions to the event related to panic attacks(e.g., sweating, breathlessness, dizziness, heart palpitations, hotflushes). Scores range from 10 to 40. Cronbach’s alpha variedbetween 0.62 and 0.79 for the ISR-E, and equaled 0.86 for theISR-P, and the convergent validity, discriminant validity, andreliability of the questionnaire were satisfactory (Bernat, Ronfeldt,Calhoun, & Arias, 1998; Falsetti et al., 1994). The internal con-sistencies in this study were good (Cronbach’s � of 0.83 and 0.71,respectively). In addition, the SCID-I interview was used to assesswhether or not the participants experienced during the event atleast one of (a) the emotions associated with a PTSD diagnosis(i.e., intense fear, horror and/or helplessness), or (b) other negativeemotions (i.e., anger, shame and/or guilt) typically associated withtraumatic events.

Early posttraumatic factors. Three categories of early post-traumatic factors were assessed: job-related consequences, per-ceived social support, and early posttraumatic symptoms (i.e.,ASD and depressive symptoms).

A questionnaire was created by the team to assess the followingjob-related consequences between the event and T1 (5 to 15 daysafter the event): the negative impact of the media coverage of theevent, satisfaction toward support offered at the job, and whetheror not six types of events happened following the traumatic event(i.e., being offered a psychological debriefing, being given daysoff or work accommodations, and seeking help at the EAP, at theirunion and/or at the internal volunteer helpline). Each variable wasassessed with a single question.

Perceived social support was assessed with the Perceived Sup-port Inventory (Guay & Miller, 2000), a self-report measure con-sisting of two subscales regarding the perceived behavior of theclosest significant other: (a) an 11-item measure of perceivedpositive social support, and (b) a 13-item measure of perceivednegative social interactions. The French version had a very goodinternal consistency (0.87), and a coefficient of convergent validitywith the Social Provisions Scale of r � .44 (Guay & Miller, 2000).The internal consistency in this study was excellent for the positivescale (Cronbach’s � � .90) and good for the negative scale(Cronbach’s � � .85).

The number of symptoms associated with ASD was assessedwith a SCID-I interview. Depressive symptoms were assessed withthe Beck Depression Inventory–II (Beck, Steer, & Brown, 1996),a 21-item questionnaire measuring depressive symptoms for thepast 2 weeks. A psychometric study with French-speaking univer-sity students (Bourque & Beaudette, 1982) revealed good concur-rent validity with other measures of depression. The internal con-sistency in this study was excellent (Cronbach’s � � .93).

Design and Data Analyses

The analyses were performed using Stata 13, and a Type I errorof 0.05 was selected. Both the bivariate and the predictive analysesof the longitudinal data were computed using nested random-effectmodels (i.e., the xtreg function on Stata). Multiple imputationswere used to deal with missing values.

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215PREDICTORS OF PTSD IN POLICE OFFICERS

For the analyses, predictors were grouped into (a) sociode-mographic and pretraumatic variables, (b) peritraumatic vari-ables, and (c) posttraumatic variables. Predictive analyses forPTSD symptoms were carried out in two phases. First, bivariateanalyses were conducted between each of the predictors and theseverity of PTSD symptoms. Predictive models of the severityof PTSD symptoms were then carried out. Variables that werenot statistically correlated with the dependent variables in thefirst phase were excluded. Variables with a distribution thatcould not be approximated by a Gaussian curve were trans-formed, and analyses were also performed on the transformeddata. Only the analyses carried out on the original data arepresented, but all tests remained significant when performed onthe transformed data.

To predict the severity of PTSD symptoms as measured onthe MPSS-SR after 1 month (T2), 3 months (T3), and 12 months(T4), a four-step nested random-effect linear regression wascarried out. Step 1 only included the time of measurement as anindependent variable, Step 2 included pretraumatic and so-ciodemographic variables, Step 3 included peritraumatic vari-ables, and Step 4 included posttraumatic variables. Models weresimplified at each step by removing variables with a statisticallynonsignificant contribution. In order for the four successivestep models to be nested in one another, variables introduced ina preceding step were retained even if they became statisticallynonsignificant afterward. The additional contribution of eachnested model was assessed with a likelihood ratio test. Eachcontributing variable was also tested in interaction with the timeof measurement to identify potential differences in effect sizebetween T2, T3, and T4.

Results

Incidence of ASD and PTSD

Within the first month following the trauma, 9% of the policeofficers developed ASD. Four of them subsequently developedPTSD, either full (n � 2) or partial (n � 2). At T2, 3% of all theparticipants met criteria for full PTSD 1 month after the traumaticevent, whereas 9% presented partial PTSD. At T3 and T4 (3months and 1 year following the event), 4% of participants metcriteria for partial PTSD. Rates for full or partial PTSD decreasedfrom 12% at one month to 4% subsequently

Predictors of PTSD Symptoms

Predictive analyses were carried out on the intensity of PTSDsymptoms (MPSS-SR) rather than on the presence or absence ofa diagnosis due to the very low number of cases with a diag-nosis (e.g., no full diagnosis and only a few partial diagnosesafter T2). Four participants never filled out the MPSS-SR andhad missing data on many predictors. As recommended formultiple imputation (von Hippel, 2007), the four cases withmissing values for the dependent variable were removed fromthe predictive analyses after imputation. Overall, less than 5%of the data was imputed.

Bivariate analyses between predictors and the severity of symp-toms are presented in Table 2. The complete matrix of pairwisecorrelations between all the variables is available in Table S1 ofthe online supplemental materials.

At Step 1 of the nested model, the severity of the PTSDsymptoms was shown to be statistically higher at T2, and not

Table 2Standardized Regression Coefficients (Beta) Between Predictors and Scores on the MPSS-SR(N � 79)

Variable (scale range) M/% Beta

Pretraumatic factorsEmotion-oriented coping strategies (16–80) 26.7 0.47���

Self-efficacy (12–48) 21.8 �0.24�

Number of childrenFor men 0.9 0.31��

For women 0.7 �0.21a

Peritraumatic factorsDuration of the event (min.) 87.9 0.26��

Initial physical reactions–ISR-P (10–40) 14.2 0.37���

Initial emotional reactions–ISR-E (15–60) 24.8 0.44���

Dissociation–PDEQ (10–50) 15.2 0.40���

Early posttraumatic factors (5–15 days after the event)Number of clinical symptoms of ASD at T1 (0–18) 2.8 0.55���

BDI-II at T1 (0–63) 3.8 0.59���

Negative support between event and T1 (12–48) 13.8 0.22�

Positive support between event and T1 (11–44) 30.5 0.23�

Negative impact of media coverage between event and T1 (1–5) 1.8 0.36���

Days off because of the event before T1 37.3% 0.23�

Sought help at the police union between event and T1 30.4% 0.33���

Sought psychological help at the EAP between event and T1 20.3% 0.36���

Note. ASD � acute stress disorder; BDI-II � Beck Depression Inventory II; ISR-E � Initial subjectivereaction - Emotional; ISR-P � Initial subjective reaction - Physical; PDEQ � Peritraumatic DissociativeExperiences Questionnaire; Time 1 � T1.a Nonsignificant, p � 0.05.� p � .05. �� p � .01. ��� p � .001.

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216 MARCHAND ET AL.

statistically different between T3 and T4. The time variable wasthus simplified to a dichotomous variable (T2 vs. T3 and T4) formodeling purposes.

At Step 2 (pretraumatic variables), the number of children wasfound to be statistically associated with more severe symptoms,but only for men and only after one child. The variable was thussimplified to only account for additional children (over one) formen. Emotion-oriented coping was also found to be associatedwith more severe PTSD symptoms.

At Step 3 (peritraumatic variables), the three scales assessingperitraumatic reactions (ISR-E, ISR-P, and PDEQ) were foundto be highly correlated predictors. To avoid problems of mul-ticollinearity, a composite indicator of peritraumatic reactionwas created to replace these three predictors. A principal com-ponent analysis was done on the three variables and the indi-cator was created by extracting the first component. The firstcomponent explained 76% of the variance. The resulting indi-cator was a better predictor than any of the original variables,and had correlations between 0.84 and 0.90 with them. Theindicator of peritraumatic reaction was also found to interactwith time and to be more strongly associated with PTSD symp-toms at T2 than afterward. To facilitate interpretation of theindicator of peritraumatic reaction, its mean was first calibratedto have a minimal value of zero (corresponding to no symp-toms). In addition, its variance was adjusted so that the unstan-dardized coefficient of the PDEQ equals 1 when the threeoriginal variables are used in a linear regression to predict theindicator. The consequence of this last transformation is that aone-unit change on this PDEQ-adjusted indicator can be inter-preted as the equivalent of a one-unit change on the PDEQ,while controlling for the two other variables. The indicator wasalso translated into an ISR-E-adjusted version and an ISR-P-adjusted version to allow for an interpretation of the indicators

with the original scales in mind. The analyses were first donewith the PDEQ-adjusted indicator, but were rerun with the otherversions to calculate the coefficients of the indicator in the unitsof each original scale.

At Step 4 (posttraumatic variables at T1), the two measuresof posttraumatic symptomatology (number of ASD symptomsand BDI) were also found to be highly correlated predictors. Acomposite symptom indicator was thus created following theprocedure explained in Step 3. The first component explained92% of the variance. The resulting indicator was a betterpredictor than the original variables and was correlated at 0.96with both of them. The analyses were first done with theASD-adjusted indicator and were subsequently rerun with theBDI-adjusted version. The indicator of posttraumatic symptomsat T1 was also found to interact with time and to be morestrongly associated with PTSD symptoms at T2 than afterward.Finally, the variable seeking help at the EAP and at the policeunion were found to statistically contribute to the model, butonly in interaction (i.e., for those who sought help both at theEAP and the police union). The variables were thus simplifiedinto a single dichotomous variable assessing whether or nothelp was sought at both places.

Each step contributed a statistically significant amount of addi-tional explained variance, with totals of explained variance at thepretraumatic, peritraumatic, and posttraumatic levels being, re-spectively, 32%, 46%, and 64%. The complete nested model isshown in Table 3.

Interpretation of the Predictive Modelfor PTSD Symptoms

As shown at the first step of the predictive model, there was astatistically significant decrease in PTSD symptoms between T2 (1

Table 3Predictive Model of PTSD Symptoms at T2, T3, and T4 (N � 79)

Included variables Baseline Pretraumatic Peritraumatic Early posttraumatic

Constant (baseline MPSS score)For T2 7.34�� 5.84�� 0.31c �0.46c

For T3 and T4 3.65�� 2.11� 0.28c 0.02c

Additional children (men only) N/A 4.05�� 4.24�� 3.76��

Emotion-oriented coping N/A 0.40�� 0.19� 0.17�

PDEQ (ISR-E/ISR-P)a PDEQ (ISR-E/ISR-P)a

Peritraumatic reactiona

For T2 N/A N/A 0.32 (0.30/0.53)�� �0.03 (–0.03/–0.04)c

For T3 and T4 N/A N/A 0.11 (0.10/0.18) 0.02 (0.02/0.04)c

ASD (BDI)b

Posttraumatic symptoms at T1b

For T2 N/A N/A N/A 1.09 (0.61)��

For T3 and T4 N/A N/A N/A 0.18 (0.10)c

Sought help between event and T1 both at the EAP and at the police union N/A N/A N/A 7.18��

Model characteristicsTotal explained variance (within/between) 0.03�� 0.32�� 0.46�� 0.64��

Additional explained variance 0.03�� 0.32�� 0.14�� 0.18��

Note. ASD � acute stress disorder; BDI-II � Beck Depression Inventory II; ISR-E � Initial subjective reaction - Emotional; ISR-P � Initial subjectivereaction - Physical; MPSS � Modified PTSD Symptom Scale; N/A� not available; PDEQ � Peritraumatic Dissociative Experiences Questionnaire; Time1 � T1; Time 2 � T2; Time 3 � T3; Time 4 � T4.a Coefficients are in units of PDEQ (ISR-E/ISR-P). b Coefficients are in units of ASD symptoms (BDI). c Nonsignificant, p � 0.05.� p � .05. �� p � .001.

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217PREDICTORS OF PTSD IN POLICE OFFICERS

month) and T3 (3 months), which was maintained between T3 andT4 (12 months). All scores for PTSD symptoms were below theclinical range, and the predicted average varied from 7.3 (at T2) to3.7 (at T3 and T4).

At the pretraumatic level, the predictive model (Step 2) high-lighted the importance of taking into consideration the use ofemotional coping strategies in predicting the intensity of PTSDsymptoms, independent of time of assessment. The more policeofficers resorted to emotional strategies when coping with stress,the more they tended to develop PTSD symptoms. In addition, themore children they have, the more male police officers tend todevelop PTSD symptoms. These two variables added 32% ofexplained variance beyond the effect of time. The level of self-efficacy had a certain predictive value according to the bivariateanalyses. However, it did not explain a statistically significantamount of variance beyond what is already explained by the use ofemotional coping strategies and the number of children.

When peritraumatic variables were added to the predictive mod-els (Step 3), analyses highlighted the added predictive value of theintensity of the reactions during the trauma. The intensity of thesereactions was a good predictor of the tendency to subsequentlydevelop PTSD symptoms, but the effect was only statisticallysignificant for the symptoms at T2. In addition, the fact that theinclusion of peritraumatic reactions in the model was associatedwith a substantial drop in the effect of emotion-oriented copingsuggests that the effect of coping on PTSD symptoms is partiallymediated by its effect on peritraumatic reactions. Peritraumaticreactions added 14% of explained variance to the model. Theduration of the event had a certain predictive value according tothe bivariate analyses, but it did not explain a statistically signif-icant amount of unique variance.

When early posttraumatic variables were added to the predictivemodels (Step 4), analyses highlighted the added predictive value ofposttraumatic symptoms at T1 and of seeking help at both the EAPand at the police union between the event and T1, which added18% of explained variance to the model. As with peritraumaticreactions, the effect of early posttraumatic reactions was statisti-cally significant only at T2. As confirmed by post hoc tests (notpresented here), the drop in the effect of peritraumatic reactionswas associated with the inclusion of early posttraumatic reactionsin the model, except for help seeking. This suggests that the effectof peritraumatic reactions on PTSD symptoms is completely me-diated by its effect on early posttraumatic symptoms. The negativeimpact of the media coverage of the event and the level of socialsupport (positive and negative) between the event and T1 also hada certain predictive value according to the bivariate analyses, butthese factors did not explain a statistically significant amount ofunique variance in the predictive model.

In summary, the presented model provides a useful frameworkthat can be adapted to the time of assessment (from a pretraumaticbaseline to 5 to 15 days after the event) to predict the emergenceof PTSD symptoms for police officers who experienced a trau-matic event.

Discussion

The present findings support the current state of knowledgeregarding the incidence rates and predictive factors of PTSD inpolice officers. Our results corroborate the findings of a pro-

spective study by Yuan et al. (2011), which also found a lowPTSD rate among police officers recruited from New York andCalifornia. In this study, only one police officer among 233officers assessed after 2 years of service reached the cutoffpoint for a PTSD diagnosis. Other studies have also found arelatively low incidence of current duty-related PTSD, withrates of 7% for police officers in the Netherlands and NewZealand (Carlier et al., 1997; Stephens & Miller, 1998) and 9%in Brazil (Maia et al., 2007).

Despite being at high risk of exposure to traumatic events,police workers appear to be quite resilient to stress. This could beexplained by various factors. For instance, the selection criteria forhiring new employees may allow for choosing those best able toassume police-related tasks (Marmar, Weiss, Metzler, Ronfeldt, &Foreman, 1996). Police officers are also trained to face stressfulsituations, which can facilitate resilience (Carlier et al., 1997;Marmar et al., 1996), and allow them to develop extensive expe-rience with a variety of dangerous situations. The low level ofsymptomatology found in our sample could also be explained bythe availability of a free, confidential, and efficient EAP. Anotherpossibility is that police officers may be inclined to underreportsymptoms of psychological distress, as the police culture maypromote more socially desirable responses in psychological assess-ments (Perrin et al., 2007; Yuan et al., 2011).

Our results are in line with Martin et al. (2009), showing that theintensity of PTSD symptoms is associated with specific risk fac-tors. Risk factors (e.g., emotional coping strategies; number ofASD symptoms; intensity of depressive symptoms; dissociative,emotional, and physical reactions) increase the likelihood of long-term consequences on psychological health after exposure to atraumatic event.

It was hypothesized that protective factors would promote ad-aptation following a traumatic event and prevent the developmentof PTSD symptoms or reduce their severity. However, unlikeMartin et al.’s (2009)study, we failed to identify any protectivefactor modulating the intensity of symptoms, such as personalityhardiness or social support during and after trauma. One possibleexplanation has to do with the potentially traumatic event that wasselected. It is conceivable that the specific event identified accord-ing to the DSM–IV–TR’s (American Psychiatric Association,2000) criteria was not one of the most meaningful in the officer’scareer. It can also be that some officers did not experience anyparticular needs in terms of social support.

Nevertheless, our results must be interpreted with caution, as itis possible that the police culture discourages officers to be openlypsychologically or physically vulnerable. In addition, two of thethree measures of hardiness had an unsatisfactory Cronbach’salpha that could explain their absence of significant associationswith the outcome. Moreover, our study was not entirely prospec-tive because some pretraumatic variables were not measured priorto the traumatic event, but in the days following it.

The present study attempted to compensate the limitations iden-tified in previous studies on predictive factors of PTSD in police.For example, these studies are correlational and retrospective,which introduces memory and recall bias and does not allow fordrawing causal inferences. The cross-sectional nature of most ofthem also hinders the identification of specific contributing factorsin the development or maintenance of PTSD. In addition, longi-tudinal studies that identify distinct predictors at varying points in

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218 MARCHAND ET AL.

time, for acute and chronic PTSD, are also lacking. Their inclusionand exclusion criteria are sometimes unclear, and their samplesizes are often small. Therefore, the current research uses a pro-spective research design and a diversified sample of police offi-cers. It is the first study to explore predictors of PTSD in a sampleof Canadian police officers. In addition, the use of standardizedinstruments allowed the assessment of several predictors that areoften overlooked, such as personality hardiness and coping strat-egies. Moreover, a distinction was made between positive socialsupport and negative social interactions, and various sources ofsupport were evaluated. To our knowledge, it is the first study thatmonitors posttraumatic symptoms early after a critical incident andat different time intervals in a police sample.

The findings of our study have implications for screening,assessment, and primary, secondary, and tertiary prevention (i.e.,treatment) of officers exposed to traumatic events in the course oftheir work. We propose the implementation of prevention andintervention strategies to improve the recovery of police officersexposed to traumatic events. These strategies could be based on thesignificant predictors identified by our research project and byother empirical studies in the field. Clinically speaking, specificinterventions could be developed and adapted in the future, asprominent factors involved in modulating PTSD (e.g., dissocia-tion, emotional and physical reactions, ASD and depressive symp-toms) may be modified using psychological strategies. For in-stance, police organizations could foster resilience in their staff byincluding in their training programs effective coping strategiessuch as problem solving, autogenic or applied relaxation, orbreathing retraining. Strategies for controlling or better managingintense emotions, reducing physiological activation, or preventingthe emergence of dissociative reactions at the time of the traumacould also be taught. In the days following a traumatic event,“psychological first aid” should be provided. Care should belimited to making people feel secure by informing them about thepossible psychological consequences and providing them withtangible and emotional support. Preventive interventions couldalso be developed to implement alternatives to emotion-orientedcoping strategies among police officers. Based on our results,seeking help at the police union and at the EAP in the daysfollowing a traumatic event could serve as a strong indicator thatPTSD symptoms might appear in the following weeks or months.Later, within the first month of the event, various effective poste-vent strategies should be suggested to officers who have experi-enced a traumatic event and who have ASD symptoms. One suchstrategy is to provide brief, intensive, cognitive–behavioral ther-apy in the form of five weekly sessions starting 2 weeks after theevent. Immediate postevent intervention can also promote appro-priate social support and encourage the verbalization of emotionsin a safe and supportive environment. Tertiary prevention shouldfocus on developing therapeutic treatments based on empiricalvalidated risk and protective factors of PTSD. Finally, the fact thatmale officers with more than one child might be more at risk ofdeveloping PTSD symptoms than other officers is both interestingand intriguing. This result suggests that gender roles moderate theeffect of traumatic events on police officers. However, furtherstudies would be required both to replicate and explain this find-ing.

References

Alexander, D. A., & Wells, A. (1991). Reactions of police officers tobody-handling after a major disaster: A before-and-after comparison.British Journal of Psychiatry, 159, 547–555.

American Psychiatric Association. (1987). Diagnostic and statistical man-ual of mental disorders (3rd ed., rev.). Washington, DC: Author.

American Psychiatric Association. (2000). Diagnostic and statistical man-ual of mental disorders (4th ed., text rev.). Washington, DC: Author.

Andrew, M. E., McCanlies, E. C., Burchfiel, C. M., Charles, L., Hartley,T. A., Fekedulegn, D., & Violanti, J. M. (2008). Hardiness and psycho-logical distress in a cohort of police officers. International Journal ofEmergency Mental Health Special Issue: Resiliency and invulnerabilityin law enforcement, 10, 137–148.

Asmundson, G. J. G., & Stapleton, J. A. (2008). Associations betweendimensions of anxiety sensitivity and PTSD symptom clusters in active-duty police officers. Cognitive Behaviour Therapy, 37, 66–75. http://dx.doi.org/10.1080/16506070801969005

Bartone, P. T. (1995). A short hardiness scale. Paper presented at the 7thAnnual Convention of the American Psychological Society, New York,NY.

Beck, A. T., Steer, R. A., & Brown, G. K. (1996.). Manuel de l’Inventairede dépression de Beck (2ème éd.) [Manual for the Beck DepressionInventory-II]. Toronto, Canada: Harcourt Brace & Company.

Bernat, J. A., Ronfeldt, H. M., Calhoun, K. S., & Arias, I. (1998).Prevalence of traumatic events and peritraumatic predictors of posttrau-matic stress symptoms in a nonclinical sample of college students.Journal of Traumatic Stress, 11, 645–664. http://dx.doi.org/10.1023/A:1024485130934

Blake, D. D., Weathers, F. W., Nagy, L. M., Kaloupek, D. G., Gusman,F. D., Charney, D. S., & Keane, T. M. (1995). The development of aclinician-administered PTSD scale. Journal of Traumatic Stress, 8,75–90. http://dx.doi.org/10.1002/jts.2490080106

Bourque, P., & Beaudette, D. (1982). Étude psychométrique du question-naire de dépression de Beck auprès d’un échantiit llon d’étudiantsuniversitaires francophones [Psychometric study of the Beck DepressionInventory in a sample of French-speaking university students]. Revuecanadienne des sciences comportementales, 14, 211–218. http://dx.doi.org/10.1037/h0081254

Carlier, I. V. E. (1999). Finding meaning in police traumas. In J. M.Violanti & D. Paton (Eds.), Police trauma: Psychological aftermath ofcivilian combat (pp. 227–239). Springfield, IL: Charles C Thomas.

Carlier, I. V. E., Lamberts, R. D., & Gersons, B. P. R. (1997). Risk factorsfor posttraumatic stress symptomatology in police officers: A prospec-tive analysis. Journal of Nervous and Mental Disease, 185, 498–506.http://dx.doi.org/10.1097/00005053-199708000-00004

Carlier, I. V. E., Lamberts, R. D., Van Uchelen, A. J., & Gersons, B. P. R.(1998). Disaster-related post-traumatic stress in police officers: A fieldstudy of the impact of debriefing. Stress Medicine, 14, 143–148. http://dx.doi.org/10.1002/(SICI)1099-1700(199807)14:3�143::AID-SMI770�3.0.CO;2-S

Carlier, I. V. E., Voerman, A. E., & Gersons, B. P. R. (2000). The influenceof occupational debriefing on post-traumatic stress symptomatology intraumatized police officers. British Journal of Medical Psychology, 73,87–98. http://dx.doi.org/10.1348/000711200160327

Darensburg, T., Andrew, M. E., Hartley, T. A., Burchfiel, C. M., Feked-ulegn, D., & Violanti, J. M. (2006). Gender and age differences inposttraumatic stress disorder and depression among Buffalo police of-ficers. Traumatology, 12, 220 –228. http://dx.doi.org/10.1177/1534765606296271

Dufour-Pineault, M. (1997). Hardiesse cognitive: Traduction française etvalidation préliminaire d’un instrument de mesure, le 15-item. Dispo-sitional Resilience (Hardiness) Scale [Cognitive boldness: French trans-lation and preliminary validation of a measuring instrument, 15-item].Master Dissertation, Université de Montréal, Montreal, Canada.

Thi

sdo

cum

ent

isco

pyri

ghte

dby

the

Am

eric

anPs

ycho

logi

cal

Ass

ocia

tion

oron

eof

itsal

lied

publ

ishe

rs.

Thi

sar

ticle

isin

tend

edso

lely

for

the

pers

onal

use

ofth

ein

divi

dual

user

and

isno

tto

bedi

ssem

inat

edbr

oadl

y.

219PREDICTORS OF PTSD IN POLICE OFFICERS

Endler, N. S., & Parker, J. D. A. (1990). Coping Inventory for StressfulSituations (CISS): Manual. Toronto, Canada: Multi-Health Systems.

Falsetti, S., Resnick, H., Kilpatrick, D., & Freedy, J. R. (1994). A reviewof the “Potential Stressful Events Interview”: A comprehensive assess-ment instrument of high and low magnitude stressors. Behavior Thera-pist, 17, 66–67.

Falsetti, S., Resnick, H., Resick, P. A., & Kilpatrick, D. (1993). TheModified PTSD Symptom Scale: A brief self-report measure of post-traumatic stress disorder. The Behavior Therapist, 16, 161–162.

First, M. B., Spitzer, R. L., Gibbon, M., & Williams, J. B. W. (1996).Structured Clinical Interview for DSM–IV Axis I Disorders. New York,NY: Biometrics Research, New York State Psychiatric Institute.

Friedman, M., & Higson-Smith, C. (2003). Building psychological resil-ience: Learning from the South African police service. In D. Paton, J. M.Violanti, & L. M. Smith (Eds.), Promoting capabilities to manageposttraumatic stress: Perspectives on resilience (pp. 103–118). Spring-field, IL: Charles C Thomas.

Gehrke, A., & Violanti, J. M. (2004). Trauma type and frequency: Riskfactors for posttraumatic stress disorder in policing. In D. Paton, J. M.Violanti, C. M. Dunning, & L. M. Smith (Eds.), Managing traumaticstress risk: A proactive approach (pp. 87–110). Springfield, IL: CharlesC Thomas.

Guay, S., Marchand, A., Iucci, S., & Martin, A. (2002). Validation de laversion québécoise de l’échelle modifiée des symptômes du trouble destress post-traumatique auprès d’un échantillon Clinique [French vali-dation of modified version of the scale of the symptoms of post-traumatic stress disorder from a clinical sample]. Revue Québécoise dePsychologie, 23, 257–270.

Guay, S., & Miller, J.-M. (2000). Traductions du Perceived SupportiveSpouse Behaviors et du Perceived Negative Spouse Behaviors [Trans-lation of the perceived supportive spouse behaviors and of the perceivednegative spouse behaviors]. Unpublished manuscript, Centre de recher-che Fernand-Seguin, Montreal, Canada.

Haisch, D. C., & Meyers, L. S. (2004). MMPI-2 assessed post-traumaticstress disorder related to job stress, coping, and personality in policeagencies. Stress and Health, 20, 223–229. http://dx.doi.org/10.1002/smi.1020

Hodgins, G. A., Creamer, M., & Bell, R. (2001). Risk factors for post-trauma reactions in police officers: A longitudinal study. Journal ofNervous and Mental Disease, 189, 541–547. http://dx.doi.org/10.1097/00005053-200108000-00007

Hovens, J. E., Falger, P. R. J., Op Den Velde, W., Schouten, E. G. W., DeGroen, J. H. M., & van Duijn, H. (1992). Occurrence of current posttraumatic stress disorder among Dutch World War II resistance veteransaccording to the SCI. Journal of Anxiety Disorders, 6, 147–157. http://dx.doi.org/10.1016/0887-6185(92)90013-W

Inslicht, S. S., McCaslin, S. E., Metzler, T. J., Henn-Haase, C., Hart, S. L.,Maguen, S., . . . Marmar, C. R. (2010). Family psychiatric history,peritraumatic reactivity, and posttraumatic stress symptoms: A prospec-tive study of police. Journal of Psychiatric Research, 44, 22–31. http://dx.doi.org/10.1016/j.jpsychires.2009.05.011

King, D. W., Vogt, D. S., & King, L. A. (2004). Risk and resilience factorsin the etiology of chronic posttraumatic stress disorder. In B. T. Litz(Ed.), Early intervention for trauma and traumatic loss (pp. 34–64).New York, NY: Guilford Press.

Kulka, R. A., Schlenger, W. E., Fairbank, J. A., Hought, R. L., Jordan, K.,Marmar, C. R., & Weiss, D. S. (1990). Trauma and the Vietnam Wargeneration: Report of findings from the National Vietnam VeteransReadjustment Study. Philadelphia, PA: Brunner/Mazel.

LeBlanc, V. R., Regehr, C., Jelley, R. B., & Barath, I. (2008). Therelationship between coping styles, performance, and responses tostressful scenarios in police recruits. International Journal of StressManagement, 15, 76–93. http://dx.doi.org/10.1037/1072-5245.15.1.76

Liberman, A. M., Best, S. R., Metzler, T. J., Fagan, J. A., Weiss, D. S.,& Marmar, C. R. (2002). Routine occupational stress and psycho-logical distress in police. Policing: An International Journal ofPolice Strategies & Management, 25, 421– 441. http://dx.doi.org/10.1108/13639510210429446

Maguen, S., Metzler, T. J., McCaslin, S. E., Inslicht, S. S., Henn-Haase, C.,Neylan, T. C., & Marmar, C. R. (2009). Routine work environmentstress and PTSD symptoms in police officers. Journal of Nervous andMental Disease, 197, 754 –760. http://dx.doi.org/10.1097/NMD.0b013e3181b975f8

Maia, D. B., Marmar, C. R., Metzler, T., Nóbrega, A., Berger, W.,Mendlowicz, M. V., . . . Figueira, I. (2007). Post-traumatic stresssymptoms in an elite unit of Brazilian police officers: Prevalence andimpact on psychosocial functioning and on physical and mental health.Journal of Affective Disorders, 97, 241–245. http://dx.doi.org/10.1016/j.jad.2006.06.004

Marmar, C. R., McCaslin, S. E., Metzler, T. J., Best, S., Weiss, D. S.,Fagan, J., . . . Neylan, T. (2006). Predictors of posttraumatic stress inpolice and other first responders. Annals of the New York Academy ofSciences, 1071, 1–18. http://dx.doi.org/10.1196/annals.1364.001

Marmar, C. R., Weiss, D. S., & Metzler, T. J. (1997). The PeritraumaticDissociative Experiences Questionnaire. In J. P. Wilson & T. M. Keane(Eds.), Assessing psychological trauma and PTSD (pp. 412–428). NewYork, NY: Guilford Press.

Marmar, C. R., Weiss, D. S., Metzler, T. J., Ronfeldt, H. M., & Foreman,C. (1996). Stress responses of emergency services personnel to the LomaPrieta earthquake Interstate 880 freeway collapse and control traumaticincidents. Journal of Traumatic Stress, 9, 63–85. http://dx.doi.org/10.1002/jts.2490090107

Marmar, C. R., Weiss, D. S., Schlenger, W. E., Fairbank, J. A., Jordan,B. K., Kulka, R. A., & Hough, R. L. (1994). Peritraumatic dissociationand posttraumatic stress in male Vietnam theater veterans. The AmericanJournal of Psychiatry, 151, 902–907. http://dx.doi.org/10.1176/ajp.151.6.902

Martin, A., & Marchand, A. (2000, November). Validity and reliability ofperitraumatic dissociative experiences francophone questionnaire.Poster presented to the 34th Annual Congress for the Association forAdvancement of Behavior Therapy (AABT), New Orleans, LA.

Martin, M., Germain, V., & Marchand, A. (2006). Facteurs de risque et deprotection dans la modulation de l’état de stress post-traumatique [Riskfactors and protection in the modulation of post-traumatic stress disor-der]. In S. Guay & A. Marchand (Eds.), Les troubles liés aux événementstraumatiques: Dépistage, évaluation et traitements (pp. 51–68). Mon-tréal, Canada: Les Presses de l’Université de Montréal.

Martin, M., Marchand, A., & Boyer, R. (2003). Trauma Severity Ques-tionnaire, Unpublished manuscript, Laboratoire d’étude du trauma, dé-partement de psychologie de l’UQAM, Montreal, Canada.

Martin, M., Marchand, A., Boyer, R., & Martin, N. (2009). Predictors ofthe development of posttraumatic stress disorder among police officers.Journal of Trauma & Dissociation, 10, 451–468. http://dx.doi.org/10.1080/15299730903143626

McCaslin, S. E., Inslicht, S. S., Metzler, T. J., Henn-Haase, C., Maguen, S.,Neylan, T. C., . . . Marmar, C. R. (2008). Trait dissociation predictsposttraumatic stress disorder symptoms in a prospective study of urbanpolice officers. Journal of Nervous and Mental Disease, 196, 912–918.http://dx.doi.org/10.1097/NMD.0b013e31818ec95d

McCaslin, S. E., Rogers, C. E., Metzler, T. J., Best, S. R., Weiss, D. S.,Fagan, J. A., . . . Marmar, C. R. (2006). The impact of personal threat onpolice officers’ responses to critical incident stressors. Journal of Ner-vous and Mental Disease, 194, 591–597. http://dx.doi.org/10.1097/01.nmd.0000230641.43013.68

McNally, V. J., & Solomon, R. M. (1999). The FBI’s critical incident stressmanagement program. FBI Law Enforcement Bulletin, 68, 20–26.

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y.

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Meffert, S. M., Metzler, T. J., Henn-Haase, C., McCaslin, S., Inslicht, S.,Chemtob, C., . . . Marmar, C. R. (2008). A prospective study of traitanger and PTSD symptoms in police. Journal of Traumatic Stress, 21,410–416. http://dx.doi.org/10.1002/jts.20350

Perrin, M. A., DiGrande, L., Wheeler, K., Thorpe, L., Farfel, M., &Brackbill, R. (2007). Differences in PTSD prevalence and associatedrisk factors among World Trade Center disaster rescue and recoveryworkers. The American Journal of Psychiatry, 164, 1385–1394. http://dx.doi.org/10.1176/appi.ajp.2007.06101645

Pole, N. (2008). Predictors of PTSD symptoms in police officers: Fromchildhood to retirement. In D. L. Delanhanty (Ed.), The psychobiology oftrauma and resilience across the lifespan (pp. 47–67). Lanham, MD:Jason Aronson.

Pole, N., Best, S. R., Weiss, D. S., Metzler, T., Liberman, A. M., Fagan, J.,& Marmar, C. R. (2001). Effects of gender and ethnicity on duty-relatedposttraumatic stress symptoms among urban police officers. Journal ofNervous and Mental Disease, 189, 442–448. http://dx.doi.org/10.1097/00005053-200107000-00005

Pole, N., Neylan, T. C., Otte, C., Henn-Hasse, C., Metzler, T. J., &Marmar, C. R. (2009). Prospective prediction of posttraumatic stressdisorder symptoms using fear potentiated auditory startle responses.Biological Psychiatry, 65, 235–240. http://dx.doi.org/10.1016/j.biopsych.2008.07.015

Roger, R. (2001). Handbook of diagnostic and structured interviewing.New York, NY: Guilford Press.

Rolland, J. P. (1994). Caractéristiques psychométriques d’un inventaire deréactions aux situations stressantes: Le CISS de Endler et Parker [Psy-chometric characteristics of an inventory of responses to stressful situ-ations]. In M. Huteau (Ed.), Les techniques psychologiques d’évaluationdes personnes (pp. 927–930). Paris, France: EAP.

Schnurr, P. P., Lunney, C. A., & Sengupta, A. (2004). Risk factors for thedevelopment versus maintenance of posttraumatic stress disorder. Jour-nal of Traumatic Stress, 17, 85–95. http://dx.doi.org/10.1023/B:JOTS.0000022614.21794.f4

Sherer, M., Maddux, J. E., Mercandante, B., Pentice-Dunn, S., Jacobs, B.,& Roger, R. W. (1982). The Self-Efficacy Scale: Construction andvalidation. Psychological Reports, 51, 663– 671. http://dx.doi.org/10.2466/pr0.1982.51.2.663

Skre, I., Onstad, S., Torgersen, S., & Kringlen, E. (1991). High interraterreliability for the Structured Clinical Interview for DSM–III–R axis I

(SCID-I). Acta Psychiatrica Scandinavica, 84, 167–173. http://dx.doi.org/10.1111/j.1600-0447.1991.tb03123.x

Solomon, Z., Benbenishty, R., Neria, Y., Abramowitz, M., Ginzburg, K., &Ohry, A. (1993). Assessment of PTSD: Validation of the revised PTSDInventory. Israel Journal of Psychiatry and Related Sciences, 30, 110–115.

Stephens, C. (1997). Debriefing, social support and PTSD in the NewZealand police: Testing a multidimensional model of organisationaltraumatic stress. Australasian Journal of Disaster and Trauma Studies,1 (1).

Stephens, C., & Long, N. (2000). Communication with police supervisorsand peers as a buffer of work-related traumatic stress. Journal ofOrganizational Behavior, 21, 407– 424. http://dx.doi.org/10.1002/(SICI)1099-1379(200006)21:4�407::AID-JOB17�3.0.CO;2-N

Stephens, C., & Miller, I. (1998). Traumatic experiences and traumaticstress disorder in the New Zealand police. Policing: An InternationalJournal of Police Strategies & Management, 21, 178–191. http://dx.doi.org/10.1108/13639519810206664

Tichenor, V., Marmar, C. R., Weiss, D. S., Metzler, T. J., & Ronfeldt,H. M. (1996). The relationship of peritraumatic dissociation and post-traumatic stress: Findings in female Vietnam theater veterans. Journal ofConsulting and Clinical Psychology, 64, 1054–1059. http://dx.doi.org/10.1037/0022-006X.64.5.1054

Violanti, J. M., & Gehrke, A. (2004). Police trauma encounters: Precursorsof compassion fatigue. International Journal of Emergency MentalHealth, 6, 75–80.

von Hippel, P. T. (2007). Regression with missing Y’s: An improvedstrategy for analyzing multiply imputed data. Sociological Methodology,37, 83–117. http://dx.doi.org/10.1111/j.1467-9531.2007.00180.x

Wilson, F. C., Poola, A. D., & Trew, K. (1997). Psychological distress inpolice officers following critical incidents. The Irish Journal of Psychol-ogy, 18, 321–340. http://dx.doi.org/10.1080/03033910.1997.10558150

Yuan, C., Wang, Z., Inslicht, S. S., McCaslin, S. E., Metzler, T. J.,Henn-Haase, C., . . . Marmar, C. R. (2011). Protective factors forposttraumatic stress disorder symptoms in a prospective study of policeofficers. Psychiatry Research, 188, 45–50. http://dx.doi.org/10.1016/j.psychres.2010.10.034

Received October 23, 2013Revision received September 23, 2014

Accepted December 14, 2014 �

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221PREDICTORS OF PTSD IN POLICE OFFICERS