Temporal Associations Among Chronic PTSD Symptoms in U.S. Combat Veterans

Abstract

The present study examined fluctuation over time in symptoms of posttraumatic stress disorder (PTSD) among 34 combat veterans (28 with diagnosed PTSD, 6 with subclinical symptoms) assessed every 2 weeks for up to 2 years (range of assessments = 13-52). Temporal relationships were examined among four PTSD symptom clusters (reexperiencing, avoidance, emotional numbing, and hyperarousal) with particular attention to the influence of hyperarousal. Multilevel cross-lagged random coefficients autoregression for intensive time series data analyses were used to model symptom fluctuation decades after combat experiences. As anticipated, hyperarousal predicted subsequent fluctuations in the 3 other PTSD symptom clusters (reexperiencing, avoidance, emotional numbing) at subsequent 2-week intervals (rs = .45, .36, and .40, respectively). Additionally, emotional numbing influenced later reexperiencing and avoidance, and reexperiencing influenced later hyperarousal (rs = .44, .40, and .34, respectively). These findings underscore the important influence of hyperarousal. Furthermore, results indicate a bidirectional relationship between hyperarousal and reexperiencing as well as a possible chaining of symptoms (hyperarousal → emotional numbing → reexperiencing → hyperarousal) and establish potential internal, intrapersonal mechanisms for the maintenance of persistent PTSD symptoms. Results suggested that clinical interventions targeting hyperarousal and emotional numbing symptoms may hold promise for PTSD of long duration.

Figure 1.

Results of analyses of within-person temporal relationships among PTSD symptom clusters across 2-week intervals (N = 34). Solid arrows indicate significant (p < .05) associations between antecedent (t – 1) and subsequent (t) symptom clusters. Dashed arrows represent control for autoregression. Partial correlation coefficients are provided as estimates of effect sizes.