A Dynamic Model for Posttraumatic Stress Disorder Among U.S. Troops in Operation Iraqi Freedom

Abstract

We develop a dynamic model in which Operation Iraqi Freedom (OIF) servicemembers incur a random amount of combat stress during each month of deployment, develop posttraumatic stress disorder (PTSD) if their cumulative stress exceeds a servicemember-specific threshold, and then develop symptoms of PTSD after an additional time lag. Using Department of Defense deployment data and Mental Health Advisory Team PTSD survey data to calibrate the model, we predict that-because of the long time lags and the fact that some surveyed servicemembers experience additional combat after being surveyed-the fraction of Army soldiers and Marines who eventually suffer from PTSD will be approximately twice as large as in the raw survey data. We cannot put a confidence interval around this estimate, but there is considerable uncertainty (perhaps ±30%). The estimated PTSD rate translates into ≈300,000 PTSD cases among all Army soldiers and Marines in OIF, with ≈20,000 new cases each year the war is prolonged. The heterogeneity of threshold levels among servicemembers suggests that although multiple deployments raise an individual's risk of PTSD, in aggregate, multiple deployments lower the total number of PTSD cases by ≈30% relative to a hypothetical case in which the war was fought with many more servicemembers (i.e., a draft) deploying only once. The time lag dynamics suggest that, in aggregate, reserve servicemembers show symptoms ≈1-2 years before active servicemembers and predict that >75% of OIF servicemembers who self-reported symptoms during their second deployment were exposed to the PTSD-generating stress during their first deployment.

Whatever happened to the soldiers? Nature-assisted therapies for veterans diagnosed with post-traumatic stress disorder: A literature review

“…Gates et al (2012) refer to results which show that 226,000 individuals serving in OEF (active Operation Enduring Freedom, Afghanistan and Operation Iraq freedom) had been diagnosed with PTSD by 2007. Atkinson et al (2009) predict in their model that the number of affected will have increased to 313,000 by 2023. The picture is the same for troops in the UK (Ministry of Defence, UK 2013).…”

Posttraumatic Stress Disorder and Cardiometabolic Disease

“…In a recent study by the Department of Veterans Affairs (VA), close to 30% of 834,463 Iraq/Afghanistan veterans seen at VA facilities had PTSD [32], and PTSD rates among these veterans may reach approximately 35% [33]. …”

Reduced cortical thickness with increased lifetime burden of PTSD in OEF/OIF Veterans and the impact of comorbid TBI

“…Symptoms can vary widely, be difficult to treat, and be functionally debilitating (Buckley et al, 2000; Rubin et al, 2008; Vasterling and Verfaellie, 2009). More than 20% of returning OEF/OIF military personnel present with PTSD (Hoge et al, 2004), much higher than the 6% reported in the civilian population (Kessler et al, 2005), and this prevalence is increasing (Atkinson et al, 2009). …”