15-Year Longitudinal Study

Study Overview

Section 721 of the 2007 National Defense Authorization Act required a 15-year longitudinal study on the effects of traumatic brain injury incurred by members of the armed forces serving in Operation Iraqi Freedom or Operation Enduring Freedom. The following questions describe what the research program intends to answer.

  • What are the long-term physical and mental health effects of TBIs?
  • What are the health care, mental health care, and rehabilitation needs?
  • What is the availability of long-term care and rehabilitation programs within and outside the DOD and VA?
  • What is the effect on family members and caregivers?

The Section 721 research program is made up of the 15-Year Longitudinal TBI Studies which include the:

  • Natural History of TBI study
  • Caregiver and Family Member study
  • Archival studies

The research program also includes the Improved Understanding of Medical and Psychological Needs in Veterans and Service Members with Chronic TBI study—or IMAP study.

This research began in 2010 and a final report will be issued in 2025. Progress reports at the three-, seven-, and 11-year marks are available to view or download. 

Learn more about some of the work being done in these new infographics, click each image to view or download.

Thumbnail image of the downloadable infographic describing the demographics of the Section 721 15-year study program structure, methodology, and timeline.  Thumbnail image of the downloadable infographic describing the demographics of the 15-year natural history of TBI study.  Thumbnail image of the downloadable infographic describing the demographics of the 15-year caregiver and family member study.

Graphic of the downloadable P D F of an infographic describing blood-based biomarkers of T B I.

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Calendar Event
Feb. 25, 2026

TBICoE Education Series: Translating 15 Years of Research on TBI Recovery and Family Impact

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The TBICoE Education Series is an enterprise-wide learning opportunity for Military Health System and Defense Health Agency stakeholders. Since inception, this series provides trainings and events relevant to warfighter readiness, discussing specialty topics and current research related to TBI.