Posttraumatic Stress Trajectories in World Trade Center Tower Survivors: Hyperarousal and Emotional Numbing Predict Symptom Change.

There is a paucity of knowledge concerning the underlying symptomatology of heterogeneous posttraumatic stress symptom (PTSS) trajectories following mass trauma, such as a terrorist attack. This study examined longitudinal PTSS trajectories using latent growth mixture modeling in 2,355 World Trade Center (WTC) tower survivors surveyed by the WTC Health Registry an average of 2.5, 5.5, and 10.5 years after the September 11, 2001 terrorist attacks. Covariates included sociodemographic characteristics, WTC-related exposure, and other traumas/stressors. Four curvilinear PTSS trajectories were identified: low symptom (74.9%), recovering (8.0%), worsening (6.7%), and chronic (10.4%). The majority of WTC survivors (85.3%) maintained stable symptom trajectories over time, with PTSS changes occurring less often. Although WTC-related exposure was associated with initial PTSS severity, exposure was not associated with chronicity or change of PTSS over time. Male gender and a higher number of post-WTC disaster life-stressors were associated with worsening symptom severity over time. Individuals with more severe hyperarousal symptoms at Wave 1, particularly of anxious arousal, were more likely to have PTSS that worsened over time, adjusted odds ratio (aOR) = 1.55. Less severe emotional numbing symptoms, particularly of dysphoria, at Wave 1, were marginally significantly associated with subsequent PTSS recovery, aOR = 0.75. Interventions that target hyperarousal and emotional numbing symptoms may mitigate a worsening of symptoms and facilitate posttraumatic recovery following future mass traumas, such as terrorist attacks. Further clinical implications are discussed.