Affiliation:
1. National Center for PTSD, VA Boston Healthcare System
2. University of Maryland, Baltimore County
3. US Army Research Institute of Environmental Medicine
4. National Center for PTSD, White River Junction VA Medical Center
5. Clinical Epidemiological Research Center
6. Yale University School of Medicine
Abstract
Abstract
Purpose
The course of posttraumatic stress disorder (PTSD) symptoms varies among veterans of warzones, but sources of variation in long-term course remain poorly understood. Modeling of symptom growth trajectories facilitates understanding predictors of individual outcomes over time. Although growth mixture modeling (GMM) has been applied to military populations, few studies have incorporated both pre-deployment and follow-up measurements over an extended time.
Methods
In this prospective study, 1087 US Army soldiers with varying military occupational specialties and geographic locations were assessed before and after deployment to the Iraq War, with long-term follow-up assessment occurring at least five years after return from deployment. The primary outcome variable was the PTSD Checklist, civilian version, summary score.
Results
GMM yielded four latent profiles: (1) primarily asymptomatic (n = 194; 17·8%), (2) post-deployment worsening symptoms (n = 84; 7·7%), (3) mild symptoms (n = 320; 29·4%), and (4) pre-existing, with chronic post-deployment elevation of symptoms (n = 489; 45·0%). Regression models comparing the primarily asymptomatic class to symptomatic classes revealed that chronic symptom classes were associated with greater stress exposure, less pre-deployment social support, identifying as a racial/ethnic minority, military reservist or veteran status at most recent assessment, and poorer pre-deployment visual memory.
Conclusions
PTSD symptom course varies considerably over time after military deployment and is associated with potentially modifiable biopsychosocial factors occurring early in its course, in addition to exposures and military status.
Trial Registration
: This study reported in this article was formally preregistered September 9, 2008 with ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT00748995).
Publisher
Research Square Platform LLC