The structure of PTSD among two cohorts of returning soldiers: before, during, and following deployment to Iraq.

Evidence suggests either a four-factor emotional numbing or dysphoria model likely reflects the underlying structure of posttraumatic stress disorder (PTSD). Questions remain as to which of these structures best represents PTSD, how the structure changes with time, the applicability of models to returning veterans, and the validity of the symptom clusters. The present study addresses these questions among two longitudinal samples of National Guard soldiers assessed prior to, during, and following a combat deployment to Iraq. Findings support a four-factor intercorrelated dysphoria model of PTSD that remains stable across samples and time points. Differential associations were observed among PTSD symptom clusters over time and between symptom clusters and both depression and combat exposure, supporting important distinctions between symptom clusters.