Since 2001, more than 2.6 million U.S. military personnel have been deployed in support of Operations Enduring Freedom, Iraqi Freedom, and New Dawn1. Between 2001 and 2016, more than 350,000 cases of traumatic brain injury (TBI) have been diagnosed in active duty Service members, most of which are concussive TBI (cTBI), also known as mild TBI2. While most Service members with cTBI achieve a full recovery in three months or less, a substantive proportion exhibit post-concussion syndrome (PCS), or post cTBI symptoms occurring beyond three months. The most commonly reported symptoms are difficulty sleeping, forgetfulness, irritability, headaches, and fatigue3.
There is undoubtedly a role of comorbid mental health concerns in PCS and clearly the symptoms of mental illness and PCS overlap (e.g., difficulty sleepy, irritability, etc.). However, PCS symptom severity has been consistently linked to white matter abnormalities4 and recent longitudinal studies found that cTBI is associated with PCS even when accounting for posttraumatic stress (PTS)3,5. For example, a recent cohort study of Service members returning from Afghanistan or Iraq determined that rates of PCS were 71% in soldiers who sustained a cTBI and exhibited PTS, 41% in soldiers who sustained a cTBI but no PTS, and 25% in controls (no cTBI and 5% had PTS)3. Furthermore, research has identified prognostic factors for PCS including history of TBIs, pre-deployment distress, deployment distress, and loss of consciousness from cTBI(s)5. This research suggests the following:
These recent research findings indicate the utility of working with an integrated care team. It is difficult to disassociate mental illness from true PCS because often both psychological and medical factors are implicated. It is therefore important to balance the likelihood of a positive prognosis for cTBI and PCS, with the knowledge that for some Service members, there may be persisting PCS that are largely distinct from psychological factors.
The opinions in CDP Staff Perspective blogs are solely those of the author and do not necessarily reflect the opinion of the Uniformed Services University of the Health Science or the Department of Defense.
1. Medicine I of. Treatment for Posttraumatic Stress Disorder in Military and Veteran Populations: Final Assessment. Washington, DC: National Academies Press, 2014.
2. DoD Worldwide Numbers for TBI.
3. Schwab K, Terrio HP, Brenner LA, et al. Epidemiology and prognosis of mild traumatic brain injury in returning soldiers: A cohort study. Neurology. 2017;88:1571–9.
4. Khong E, Odenwald N, Hashim E, et al. Diffusion Tensor Imaging Findings in Post-Concussion Syndrome Patients after Mild Traumatic Brain Injury: A Systematic Review. Front Neurol. 2016;7:156.
5. Stein MB, Ursano RJ, Campbell-Sills L, et al. Prognostic Indicators of Persistent Post-Concussive Symptoms after Deployment-Related Mild Traumatic Brain Injury: A Prospective Longitudinal Study in U.S. Army Soldiers. J Neurotrauma. 2016;33:2125–32.
6. Adams RS, Corrigan JD, Mohr BA, et al. Traumatic Brain Injury and Post-Deployment Binge Drinking among Male and Female Army Active Duty Service Members Returning from Operation Enduring Freedom/Operation Iraqi Freedom. J Neurotrauma. 2017;34:1457–65.
7. Adams RS, Larson MJ, Corrigan JD, et al. Combat-Acquired Traumatic Brain Injury, Posttraumatic Stress Disorder, and Their Relative Associations With Postdeployment Binge Drinking. J Head Trauma Rehabil. 2016;31:13–22.
8. Grossbard J, Malte CA, Lapham G, et al. Prevalence of Alcohol Misuse and Follow-Up Care in a National Sample of OEF/OIF VA Patients With and Without TBI. Psychiatr Serv. 2017;68:48–55.
9. Stavro K, Pelletier J, Potvin S. Widespread and sustained cognitive deficits in alcoholism: a meta-analysis. Addict Biol. 2013;18:203–13.
10. Wood R, McHugh L. Decision making after traumatic brain injury: A temporal discounting paradigm. J Int. 2013.
11. Karr JE, Areshenkoff CN, Duggan EC, et al. Blast-Related Mild Traumatic Brain Injury: A Bayesian Random-Effects Meta-Analysis on the Cognitive Outcomes of Concussion among Military Personnel. Neuropsychol Rev. 2014;24:428–44.
12. Ponsford J, Tweedly L, Taffe J. The relationship between alcohol and cognitive functioning following traumatic brain injury. J Clin Exp Neuropsychol. 2013;35:103–12.
13. Baguley IJ, Felmingham KL, Lahz S, et al. Alcohol abuse and traumatic brain injury: effect on event-related potentials. Arch Phys Med Rehabil. 1997;78:1248–53.
14. Teng SX, Katz PS, Maxi JK, et al. Alcohol exposure after mild focal traumatic brain injury impairs neurological recovery and exacerbates localized neuroinflammation. Brain Behav Immun. 2015;45:145–56.
15. Silverberg N, Panenka W, Iverson G. Alcohol Consumption Does not Impede Recovery from Mild to Moderate Traumatic Brain Injury. J. 2016.
16. Jenkins P, Mehta M, Sharp D. Catecholamines and cognition after traumatic brain injury. Brain. 2016.
17. Longo DL, Volkow ND, Koob GF, et al. Neurobiologic Advances from the Brain Disease Model of Addiction. N Engl J Med. 2016;374:363–71.
18. Volkow ND, Baler RD. NOW vs LATER brain circuits: implications for obesity and addiction. Trends Neurosci. 2015;38:345–52.
19. Moreno-López L, Manktelow AE, Sahakian BJ, et al. Anything goes? Regulation of the neural processes underlying response inhibition in TBI patients. Eur Neuropsychopharmacol. 2017;27:159–69.
20. Manktelow AE, Menon DK, Sahakian BJ, et al. Working Memory after Traumatic Brain Injury: The Neural Basis of Improved Performance with Methylphenidate. Front Behav Neurosci. 2017;11:58.
21. Johansson B, Wentzel A-P, Andréll P, et al. Methylphenidate reduces mental fatigue and improves processing speed in persons suffered a traumatic brain injury. Brain Inj. 2015;29:758–65.
22. McCabe SE, Knight JR, Teter CJ, et al. Non-medical use of prescription stimulants among US college students: prevalence and correlates from a national survey. Addiction. 2005;100:96–106.
23. Wilens TE, Adler LA, Adams J, et al. Misuse and Diversion of Stimulants Prescribed for ADHD: A Systematic Review of the Literature. J Am Acad Child Adolesc Psychiatry. 2008;47:21–31.