2 - (IOP 6) Identifying Latent Classes of Post-deployment Symptoms: Depression, Anxiety, PTSD, and Cognitive Impairment Among Military Personnel

Background: Post-traumatic stress disorder (PTSD) is a complex, debilitating condition with significant variability in its development and progression. Emotional and behavioral responses to traumatic events vary greatly, complicating prediction, diagnosis, and treatment. Military personnel exposed to combat are at higher risk for PTSD and related comorbidities. This risk increases if mood and anxiety disorders pre-exist. PTSD often co-occurs with other mood and anxiety disorders, affecting symptom presentation, severity, and complicating diagnosis and treatment. Examining groupings of symptoms across diagnoses offers an avenue for pursuing added clarity in diagnosing and treating complex and interrelated problems and symptoms. Understanding diverse responses to trauma, especially in populations with high exposure like military personnel, is essential.

Objectives: The Fort Campbell Cohort study, a longitudinal study of active-duty military personnel at Fort Campbell, Kentucky, assesses pre- and post-deployment behavioral, biological, and neurocognitive markers. This study aims to examine PTSD, major depressive disorder (MDD), and generalized anxiety disorder (GAD) symptoms in military personnel with varying deployment experiences. Additionally, it explores sleep disturbances and cognitive impairment. The goal is to identify subgroups with common symptom patterns across disorders, which could inform treatment approaches and improve understanding of long-term mental health outcomes.

Methods: Latent class analysis was conducted on data from 258 soldiers participating in Phases 1, 3, and 4 of the study. Symptoms of sleep (PSQI), GAD (GAD-7), MDD (PHQ-8), PTSD (PCL-5), and cognitive impairment were analyzed across three time points. Cross-sectional and longitudinal patterns were explored to identify subgroups and examine how sleep, mood, traumatic stress, and cognitive performance cluster over time.

Results: Analysis of Phase 1 (pre-deployment) data identified three distinct classes based on reported symptoms from the PSQI, GAD-7, and PCL-5:
Class 1: Individuals with good sleep quality, minimal anxiety, and no PTSD symptoms.
Class 2: Individuals with severe sleep difficulties, moderate to severe anxiety, and high PTSD symptoms.
Class 3: Individuals with moderate sleep difficulties, mild to moderate anxiety, and no PTSD symptoms.
These preliminary analyses will be replicated in Phases 3 and 4 to track changes in symptom classes over time. We expect at least two trajectories: one showing worsening symptoms and another showing a resilient pattern. We hypothesize that individuals in Class 2 at Phase 1, who show the highest symptom levels, will be more likely to maintain symptoms post-deployment.

Discussion: This study highlights the variability of psychological symptoms among military personnel before and after deployment. Identifying symptom groupings offers insights into diagnostic approaches, providing a transdiagnostic perspective on mood and trauma-related symptoms. Future research will focus on identifying predictors of class membership to improve early detection, diagnosis, and treatment of mental health issues among active-duty soldiers and veterans.