We provide an overview of previous research conducted by our group on risk and resilience factors for PTSD symptoms in police and other first responders. Based on our work, the findings of other investigators on individual differences in risk for PTSD, and drawing on preclinical studies fear conditioning and extinction, we propose a conceptual model for the development of PTSD symptoms emphasizing the role of vulnerability and resilience to peritraumatic panic reactions. We tested this conceptual model in a cross-sectional sample of police officers (n = 715). Utilizing an hierarchical linear regression model we were able to explain 39.7% of the variance in PTSD symptoms. Five variables remained significant in the final model; greater peritraumatic distress (beta = 0.240, P < .001), greater peritraumatic dissociation (beta = 0.174, P < .001), greater problem-solving coping (beta = 0.103, P < .01), greater routine work environment stress (beta = 0.182, P < .001), and lower levels of social support (beta = -0.246, P < .001). These results were largely consistent with the proposed conceptual model. Next steps in this line of research will be to test this model prospectively in a sample of 400 police academy recruits assessed during training and currently being followed for the first 2 years of police service.

NCT00881647.

Police work is one of the most stressful occupations. Previous research has indicated that work stress and trauma exposure may place individuals at heightened risk for the development of depression symptomatology. This prospective longitudinal study was designed to examine predictors of depression symptoms in police service.119 healthy police recruits from an ongoing prospective study were examined. Participants completed baseline measures of depression symptoms, childhood trauma exposure, neuroticism, and self-worth during academy training. Follow-up measures of depression symptoms, PTSD symptoms, critical incident exposure, negative life events, and routine work environment stress were assessed after 12 months of police service. Hierarchical linear regression analysis was conducted to examine predictors of current levels of depression symptoms, controlling for baseline depression symptoms and current PTSD symptoms. Greater childhood trauma exposure, lower self-worth during training and greater perceived work stress in the first year of police service predicted greater depression symptoms at 12 months. Depression symptoms at one year of police service were partly independent from PTSD symptoms at 12 months. Greater childhood trauma exposure and lower self-worth during training may be important variables to screen as risk factors for duty-related depression. Strategies to reduce routine work environment stress have potential to decrease duty-related depression in law enforcement.

This study examined the relationship between routine work environment stress and posttraumatic stress disorder (PTSD) symptoms in a sample of police officers (N = 180) who were first assessed during academy training and reassessed 1-year later. In a model that included gender, ethnicity, traumatic exposure prior to entering the academy, current negative life events, and critical incident exposure over the last year, routine work environment stress was most strongly associated with PTSD symptoms. We also found that routine work environment stress mediated the relationship between critical incident exposure and PTSD symptoms and between current negative life events and PTSD symptoms. Ensuring that the work environment is functioning optimally protects against the effects of duty-related critical incidents and negative life events outside police service.

Cognitive, coping, and trauma symptom predictors of posttraumatic growth (PTG; measured with the Posttraumatic Growth Inventory) were examined in a large convenience sample (n =1505) participating in a longitudinal Internet-based study following the terrorist attacks of 9/11/01. Results indicate that initial PTG levels (mean 9 weeks post-attacks) were generally associated with higher trauma symptoms (measured with the PTSD Checklist - Specific), positive changes in worldview (measured with the Changes in Outlook Questionnaire), more denial, and less behavioral disengagement (measured with the Brief COPE). Additionally, PTG had a curvilinear association with level of trauma symptoms, such that those reporting symptoms at intermediate levels reported the highest levels of growth. Levels of PTG declined somewhat over time with the exception of Spiritual Change. As expected, PTG levels at follow-up (mean 6.5 months post-attacks) were primarily predicted by initial PTG levels; however, decreases from baseline in trauma symptoms and increases from baseline in positive worldview, acceptance, and positive reframing were also associated with higher reported posttraumatic growth at follow-up. These findings suggest that there may be a range of traumatic experience most conducive to growth and they also highlight the important contributions of cognitive and coping variables to psychological thriving in short- and longer-term periods following traumatic experience.

This study examined the relationship between killing or seriously injuring someone in the line of duty and mental health symptoms in a sample of police officers (N = 400) who were first assessed during academy training and at five additional time points over three years. We found that nearly 10% of police officers reported having to kill or seriously injure someone in the line of duty in the first three years of police service. After controlling for demographics and exposure to life threat, killing or seriously injuring someone in the line of duty was significantly associated with PTSD symptoms (p< .01) and marginally associated with depression symptoms (p < .06). These results highlight the potential mental health impact of killing or seriously injuring someone in the line of duty. Greater attention to mental health services following these types of exposures can serve as a preventative measure for police officers who have been negatively impacted.

The relationships of posttraumatic growth to peritraumatic reactions and posttraumatic stress symptoms were examined in 93 Sri Lankan university students who had experienced a traumatic life event. Posttraumatic growth was associated with peritraumatic dissociation and posttraumatic stress symptoms, but was not associated with peritraumatic emotional distress. Results indicated a curvilinear relationship between peritraumatic dissociation and posttraumatic growth and between posttraumatic stress symptoms and posttraumatic growth. In a regression model predicting posttraumatic growth scores, each of the quadratic relationships of peritraumatic dissociation and posttraumatic stress symptoms to posttraumatic growth were statistically significant, and combined accounted for 22% of the variance. Results suggest that moderate levels of peritraumatic dissociation and symptoms are most associated with the greatest levels of growth.

Although police officers are frequently exposed to potentially traumatic incidents, only a minority will develop chronic Posttraumatic Stress Disorder (PTSD). Identifying and understanding protective factors could inform the development of preventive interventions; however, few studies have examined this. In the present prospective study, 233 police officers were assessed during academy training and again following two years of police service. Caucasian race, less previous trauma exposure, and less critical incident exposure during police service as well as greater sense of self-worth, beliefs of greater benevolence of the world, greater social support and better social adjustment, all assessed during academy training, were associated with lower PTSD symptoms after two years of service. Positive personality attributes assessed during training with the NEO Five-Factor Personality Inventory were not associated with lower PTSD symptoms. In a hierarchical linear regression model, only Caucasian race, lower critical incident exposure during police service, greater assumptions of benevolence of the world and better social adjustment during training remained predictive of lower PTSD symptoms after two years of police service. These results suggest that positive world assumptions and better social functioning during training may protect police officers from critical incident related PTSD.