Ritika Singh

BACKGROUND: Longitudinal symptoms of post-traumatic stress disorder (PTSD) are often characterized by heterogeneous trajectories, which may have unique pre-, peri- and post-trauma risk and protective factors. To date, however, no study has evaluated the nature and determinants of predominant trajectories of PTSD symptoms in World Trade Center (WTC) responders. METHOD: A total of 10835 WTC responders, including 4035 professional police responders and 6800 non-traditional responders (e.g. construction workers) who participated in the WTC Health Program (WTC-HP), were evaluated an average of 3, 6 and 8 years after the WTC attacks. RESULTS: Among police responders, longitudinal PTSD symptoms were best characterized by four classes, with the majority (77.8%) in a resistant/resilient trajectory and the remainder exhibiting chronic (5.3%), recovering (8.4%) or delayed-onset (8.5%) symptom trajectories. Among non-traditional responders, a six-class solution was optimal, with fewer responders in a resistant/resilient trajectory (58.0%) and the remainder exhibiting recovering (12.3%), severe chronic (9.5%), subsyndromal increasing (7.3%), delayed-onset (6.7%) and moderate chronic (6.2%) trajectories. Prior psychiatric history, Hispanic ethnicity, severity of WTC exposure and WTC-related medical conditions were most strongly associated with symptomatic trajectories of PTSD symptoms in both groups of responders, whereas greater education and family and work support while working at the WTC site were protective against several of these trajectories. CONCLUSIONS: Trajectories of PTSD symptoms in WTC responders are heterogeneous and associated uniquely with pre-, peri- and post-trauma risk and protective factors. Police responders were more likely than non-traditional responders to exhibit a resistant/resilient trajectory. These results underscore the importance of prevention, screening and treatment efforts that target high-risk disaster responders, particularly those with prior psychiatric history, high levels of trauma exposure and work-related medical morbidities.

BACKGROUND: Post-traumatic stress disorder (PTSD) in response to the World Trade Center (WTC) disaster of 11 September 2001 (9/11) is one of the most prevalent and persistent health conditions among both professional (e.g. police) and non-traditional (e.g. construction worker) WTC responders, even several years after 9/11. However, little is known about the dimensionality and natural course of WTC-related PTSD symptomatology in these populations. METHOD: Data were analysed from 10 835 WTC responders, including 4035 police and 6800 non-traditional responders who were evaluated as part of the WTC Health Program, a clinic network in the New York area established by the National Institute for Occupational Safety and Health. Confirmatory factor analyses (CFAs) were used to evaluate structural models of PTSD symptom dimensionality; and autoregressive cross-lagged (ARCL) panel regressions were used to examine the prospective interrelationships among PTSD symptom clusters at 3, 6 and 8 years after 9/11. RESULTS: CFAs suggested that five stable symptom clusters best represent PTSD symptom dimensionality in both police and non-traditional WTC responders. This five-factor model was also invariant over time with respect to factor loadings and structural parameters, thereby demonstrating its longitudinal stability. ARCL panel regression analyses revealed that hyperarousal symptoms had a prominent role in predicting other symptom clusters of PTSD, with anxious arousal symptoms primarily driving re-experiencing symptoms, and dysphoric arousal symptoms primarily driving emotional numbing symptoms over time. CONCLUSIONS: Results of this study suggest that disaster-related PTSD symptomatology in WTC responders is best represented by five symptom dimensions. Anxious arousal symptoms, which are characterized by hypervigilance and exaggerated startle, may primarily drive re-experiencing symptoms, while dysphoric arousal symptoms, which are characterized by sleep disturbance, irritability/anger and concentration difficulties, may primarily drive emotional numbing symptoms over time. These results underscore the importance of assessment, monitoring and early intervention of hyperarousal symptoms in WTC and other disaster responders.

OBJECTIVE: To characterize the prevalence, risk and protective correlates, and clinical characteristics associated with probable subthreshold posttraumatic stress disorder (PTSD) in police and nontraditional (eg, construction workers) World Trade Center (WTC) responders a median of 12.2 years after September 11, 2001. METHODS: A total of 4,196 WTC responders, monitored via the WTC Health Program, completed a web-based survey between 2012 and 2014 assessing a range of variables, including demographics, WTC exposures, medical and psychiatric comorbidities, and mental health services use. The sample included 2,029 police responders and 2,167 nontraditional responders. Current (past-month) probable WTC-related PTSD level (none, subthreshold, or full PTSD) was assessed based on DSM-IV criteria using the PTSD Checklist-Specific Stressor version (PCL-S). RESULTS: The prevalence of current probable full and subthreshold WTC-related PTSD in police responders was 9.3% and 17.5%, respectively, and in nontraditional responders was 21.9% and 24.1%, respectively. Risk and protective correlates for subthreshold PTSD included post-9/11 medical comorbidities and traumatic events (odds ratios [ORs] = 1.1-1.2). Clinical characteristics included elevated rates of comorbid depression (OR = 3.2 and 3.9 for subthreshold PTSD and 17.2 and 30.3 for full PTSD for nontraditional and police responders, respectively). Among responders with subthreshold PTSD, police were more likely to have accessed mental health services and utilized a greater variety of treatments than nontraditional responders. CONCLUSIONS: Overall, 26.8% of police and 46.0% of nontraditional responders met criteria for probable WTC-related full or subthreshold PTSD an average of 12 years after 9/11. Probable subthreshold PTSD, which is not typically assessed in clinical settings, was more prevalent than probable full PTSD and was associated with significantly elevated rates of psychiatric comorbidities, functional impairment, and reduced quality of life. These findings underscore the importance of assessing, monitoring, and possibly treating subthreshold PTSD in WTC and other disaster responders.