Background: Symptom-level variation in posttraumatic stress disorder (PTSD) has not yet been examined in the early post-deployment phase, but may be meaningful etiologically, prognostically, and clinically.
Methods: Using latent class analysis (LCA), we examined PTSD symptom heterogeneity in a cohort of participants from the Marine Resiliency Study (MRS), a longitudinal study of combat Marines deployed to Iraq and Afghanistan (N=892). Typologies of PTSD symptom presentation were examined at one month pre-deployment and again one, five, and eight months post-deployment.
Results: Heterogeneity in PTSD symptom presentation was evident at each assessment point, and the degree of symptom heterogeneity (i.e., the number of classes identified) differed by time point. Symptom patterns stabilized over time from notable symptom fluctuations during the early post-deployment period to high, medium, and low symptom severity by eight months post-deployment. Hypervigilance and exaggerated startle were frequently endorsed by participants in the initial month post-deployment. Flashbacks, amnesia, and foreshortened future were infrequently endorsed. Greater combat exposure, lifespan trauma, and avoidant coping generally predicted worse outcomes.
Limitations: Data were self-report and may have limited generalizability due to our lack of women and inclusion of only combat Marines. Attrition and re-ranging of data resulted in significant missing data and affected the representativeness of the sample.
Conclusions: Symptom-level variability is highest in the month following deployment and then stabilizes over time. Should post-deployment assessments occur too soon, they may capture common and transient early post-deployment reactions, particularly anxious arousal.
Keywords: Afghanistan; Combat; Latent class; Military; PTSD; Symptoms.
Published by Elsevier B.V.