In 1998, the IOM began a series of congressionally-mandated studies to examine the scientific and medical literature on the potential health effects of chemical and biological agents related to the 1991 Gulf War. 

This study comprehensively reviewed, evaluated, and summarized the peer-reviewed scientific and medical literature regarding the association between stress and long-term adverse health effects in Gulf War veterans, specifically the physiologic, psychologic, and psychosocial effects of stress.The study was not  limited to veterans of the 1991 Gulf War, but also included veterans of more recent conflicts (Operation Iraqi Freedom; Operation Enduring Freedom).

At the request of the Department of Veterans Affairs, the Institute of Medicine (IOM) conducted a study on Post-Traumatic Stress Disorder (PTSD). Specifically related to the assessment and diagnosis of PTSD, the committee reviewed and commented on the objective measures used in the diagnosis of PTSD and known risk factors for the development of PTSD. 

IOM used the existing committee on Gulf War and Health:  Physiologic, Psychologic and Psycholosocial Effects of Deployment Related Stress to complete the task related to diagnosis and validity of diagnostic instruments and treatment issues.