About the Study

The Millennium Cohort Study is a DoD research project that was created in 2001 in response to growing public concern about the potential health effects of deployments following the Vietnam and Gulf War conflicts. Although the original designers of the Millennium Cohort Study could not foresee the post-2001 military conflicts, the project is perfectly positioned to address health outcomes related to these operations.

The overarching goal of the Millennium Cohort Study is to determine how military related experiences affect the long-term health of service members. We hope the findings of our study will help define healthcare policy for future generations of military personnel and guide prevention and treatment programs. With over a quarter of a million service members enrolled since 2001, the Millennium Cohort Study is the largest and longest-running health study in military history and spans multiple generations of warfighters.

Facts about the Cohort

Millennium Cohort Study participants are diverse in terms of demographic characteristics and military and deployment experience.

  • Most participants are men (69%) with 31% women.
  • Participants predominantly served in the Army (43%), followed by the Air Force (31%), Navy (15%), Marine Corps (9%), and Coast Guard (2%).
  • Over half (60%) have deployed at least once during their military service.
  • More than half of participants at the time of enrollment were junior enlisted (58%), followed by 26% senior enlisted, and 17% officers.
Study Timeline

About Timeline

The Investigators

Principal Investigator

Rudy Rull, PhD, MPH is the Principal Investigator of the Millennium Cohort Study at the Naval Health Research Center. Dr. Rull received his PhD and MPH in Epidemiology from the University of California, Los Angeles and BA in Environmental Sciences from the University of California, Berkeley. In addition to military health, his research has focused on the assessment of environmental exposures to metals, pesticides, and other pollutants using biological markers, environmental databases, geographic information systems and mapping technologies, and the effects of these exposures on cancer, respiratory health, and birth defects.

Past Principal Investigators

Gregory C. Gray, MD, MPH, Captain, USN, Retired1999 - 2001
Margret A. K. Ryan, MD, MPH, Captain, USN, Retired2001 - 2008
Tyler C. Smith, PhD, MS2008 - 2011
Nancy F. Crum, MD, MPH2011 - 2013
Martin R. White, MPH2013 - 2014
David D. Luxton, PhD2014 - 2015
CAPT Dennis Faix, MD, MPH, MC, USN2015 - 2017

The Study Staff

Our study staff of epidemiologists, biostatisticians, research psychologists, analysts, programmers and research coordinators are comprised of both military and civilian professionals. The staff is located at the Deployment Health Research Department, Naval Health Research Center in San Diego, California.

The Strategic Board

The Millennium Cohort Team wishes to acknowledge the contributions of the Strategic Board members to the Millennium Cohort Study:

Current Members

George Anderson, MD, MPH
Major General, USAF, MC Ret.

Kelley Brix, MD, MPH
Research and Engineering Directorate
Defense Health Agency

Towanda Street, PhD, MA
Office of Deputy Assistant Secretary of Defense for
Military Community and Family Policy

Sally Haskell, MD, MS
Women’s Health Services, Veterans Health Administration
Department of Veterans Affairs

Gregory Leskin, PhD
Military and Veteran Families Program
UCLA National Center for Child Traumatic Stress

Joyce Raezer, MA
National Military Family Association (retired)

Joseph Sharpe, Jr., MA
Director of the National Employment and Education Division,
The American Legion

Donald Shell, MD, MA
Office of the Assistant Secretary of Defense for Health Affairs,
Health Services Policy and Oversight

Past Members

Lisa SpahrMember 2000 - 2001
Dr. Noel WeissMember 2000 - 2001
John D. Potter, MD, PhDMember 2000 - 2002
Bradley N. Doebbeling, MD, MScMember 2000 - 2005
CDR Al Pavich, USN, RetiredMember 2000 - 2007
Michael J. O’RourkeMember 2000 - 2010
G. Marie Swanson, PhD, MPHMember 2000 - 2015
Elizabeth Barrett-Connor, MD, DCMTMember 2000 - 2015
Dan G. Blazer, II, MD, PhD, MPHMember 2000 - 2013
Lawrence A. Palinkas, PhDMember 2000 - 2013
K. Michael Peddecord, DrPHMember 2000 - 2015
Harold M. Koenig, MD, Vice Admiral, USN, RetiredMember 2000 - 2015
Shannon Middleton, MPHMember 2002 - 2005
Laurence G. Branch, PhDMember 2002 - 2004
Marc Weisskopf, PhD, ScDMember 2011 - 2015
Rhonda Cornum, MD, Brigadier General, USA, RetiredMember 2011 - 2015
Michael E. Kilpatrick, MDMember 2011 - 2015
Judith Dekle, MSW, LCSWMember 2015 - 2016
Robert Bossarte, PhDMember 2015 - 2017
Yuko Whitestone, PhDMember 2017 - 2018
Amy Justice, MD, PhDMember 2018 - 2019
Ralph Loren Erickson, MD, DrPHMember 2018 - 2021
Colin Chinn MD, MHSMember 2019 - 2019
Cathy Flynn, PhDMember 2019 - 2019
Benjamin Karney, PhDMember 2019 - 2022