Association Between Traumatic Brain Injury and Risk of Posttraumatic Stress Disorder in Active-Duty Marines
Kate A. Yurgil, PhD1,2; Donald A. Barkauskas, PhD3; Jennifer J. Vasterling, PhD4,5,6; Caroline M. Nievergelt, PhD1,2,7; Gerald E. Larson, PhD8; Nicholas J. Schork, PhD9; Brett T. Litz, PhD4,5,6,10; William P. Nash, MD11; Dewleen G. Baker, MD1,2,7 ; for the Marine Resiliency Study Team
1Department of Psychiatry, Veterans Affairs San Diego Healthcare System, San Diego, California
2Veterans Affairs Center of Excellence for Stress and Mental Health, San Diego, California
3Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles
4Department of Psychiatry, Boston University School of Medicine, Boston, Massachusetts
5Division of Behavioral Sciences, Veterans Affairs National Center for Posttraumatic Stress Syndrome, Boston, Massachusetts
6Department of Psychology, Veterans Affairs Boston Healthcare System, Boston, Massachusetts
7Department of Psychiatry, School of Medicine, University of California, San Diego
8Department of Behavioral Science and Epidemiology, Naval Health Research Center, San Diego, California
9Department of Molecular and Experimental Medicine, Scripps Translational Research Institute, San Diego, California
10Department of Psychology, Boston University School of Medicine, Boston, Massachusetts
11Boston Veterans Affairs Research Institute, Boston, Massachusetts
JAMA Psychiatry. 2014;71(2):149-157. doi:10.1001/jamapsychiatry.2013.3080.
Importance: Whether traumatic brain injury (TBI) is a risk factor for posttraumatic stress disorder (PTSD) has been difficult to determine because of the prevalence of comorbid conditions, overlapping symptoms, and cross-sectional samples.
Objective: To examine the extent to which self-reported predeployment and deployment-related TBI confers increased risk of PTSD when accounting for combat intensity and predeployment mental health symptoms.
Design, Setting and Participants: As part of the prospective, longitudinal Marine Resiliency Study (June 2008 to May 2012), structured clinical interviews and self-report assessments were administered approximately 1 month before a 7-month deployment to Iraq or Afghanistan and again 3 to 6 months after deployment. The study was conducted at training areas on a Marine Corps base in southern California or at Veterans Affairs San Diego Medical Center. Participants for the final analytic sample were 1648 active-duty Marine and Navy servicemen who completed predeployment and postdeployment assessments. Reasons for exclusions were nondeployment (n = 34), missing data (n = 181), and rank of noncommissioned and commissioned officers (n = 66).
Main Outcomes and Measures: The primary outcome was the total score on the Clinician-Administered PTSD Scale (CAPS) 3 months after deployment.
Results: At the predeployment assessment, 56.8% of the participants reported prior TBI; at postdeployment assessment, 19.8% reported sustaining TBI between predeployment and postdeployment assessments (ie, deployment-related TBI). Approximately 87.2% of deployment-related TBIs were mild; 250 of 287 participants (87.1%) who reported posttraumatic amnesia reported less than 24 hours of posttraumatic amnesia (37 reported ≥24 hours), and 111 of 117 of those who lost consciousness (94.9%) reported less than 30 minutes of unconsciousness. Predeployment CAPS score and combat intensity score raised predicted 3-month postdeployment CAPS scores by factors of 1.02 (P < .001; 95% CI, 1.02-1.02) and 1.02 (P < .001; 95% CI, 1.01-1.02) per unit increase, respectively. Deployment-related mild TBI raised predicted CAPS scores by a factor of 1.23 (P < .001; 95% CI, 1.11-1.36), and moderate/severe TBI raised predicted scores by a factor of 1.71 (P < .001; 95% CI, 1.37-2.12). Probability of PTSD was highest for participants with severe predeployment symptoms, high combat intensity, and deployment-related TBI. Traumatic brain injury doubled or nearly doubled the PTSD rates for participants with less severe predeployment PTSD symptoms.
Conclusions and Relevance: Even when accounting for predeployment symptoms, prior TBI, and combat intensity, TBI during the most recent deployment is the strongest predictor of postdeployment PTSD symptoms.