DOD and RAND Release Report on Stress Effects on Health

WASHINGTON, May 19, 1999 (GulfLINK) A newly released scientific literature review conducted by the RAND Corporation finds evidence that exposure to stressful events including combat or war zone exposure can contribute to psychological or bodily symptoms. The report, A Review of the Scientific Literature as it Pertains to Gulf War Illnesses, Volume 4: Stress," is the latest in a series of eight scientific literature reviews intended to complement federal research into the nature of Gulf War illnesses. The report summarizes hundreds of articles, technical reports, scientific surveys and empirical data in an attempt to identify information that may be useful in the analysis of the effects of stress on the health of Gulf War veterans.

The RAND authors identified 15 studies that evaluated the relationship between exposure to stress during the Gulf War and the development of symptoms of Post Traumatic Stress Disorder (PTSD). All 15 studies demonstrated a modest correlation between stress and PTSD. The correlation between stress and health problems was stronger in persons exposed to very high stress levels (such as actual combat, a SCUD missile attack, or graves registration duties).

 Ten studies reported on the relationship between stress exposure and mental health problems such as depression or anxiety. Most of these studies provided evidence of a modest correlation between stress exposure and psychological distress. However, the studies that evaluated a link between stress exposure during the Gulf War and physical symptoms, such as headaches or joint pains, were too limited to draw definitive conclusions.

"Although it is inappropriate to rely upon stress exposure as a default explanation for the myriad health problems reported by Gulf War veterans in the absence of a thorough review of research concerning all plausible causes," said RAND, " we think it equally inappropriate to assume that stress played no role. To do so would ignore what the scientific literature shows about the relationship between stress and health."

According to the RAND study, historically, psychological and physical symptoms commonly observed after exposure to stressful events include depression, anxiety, fatigue, impaired memory and concentration, headaches, back and neck aches, gastrointestinal complaints, and breathing difficulty. All of these symptoms are common in the medical complaints of Gulf War veterans, suggesting to some researchers that stress may be one of the underlying risk factors for their illnesses.

To date, several of the medical studies about the Gulf War have dealt specifically with the relationship between stress and illness. However, some of the published studies relied exclusively on comparisons between deployed and non-deployed troops, without actually assessing stress exposure explicitly.

"In most cases," said Bernard Rostker, the special assistant for Gulf War illnesses, "with the exception of Post Traumatic Stress Disorder, there were no medical evaluations performed that would help us make more definitive conclusions with regard to a stress-illness connection. A majority of the information was self-reported by veterans responding to questionnaires instead of medical interviews and physical examinations. This method simplifies the collection of data, but introduces significant areas for interpretation on the part of both the survey participant and the surveyor. In many cases, the response groups were too small to be statistically significant. We just can't generalize the results of some of these studies as applying to the majority of Gulf veterans."

The RAND report describes in depth the stresses most commonly cited by Gulf War veterans in surveys taken before, during, and after the war. As the researchers expected, combat-related stresses were evident though relatively few Gulf War veterans experienced actual combat situations, as compared to the numbers of service members who deployed to the theater. A significant source of stress common to all was the deployment process itself.

"Many service members were not prepared to deploy," Rostker said. "No one could tell them how long they would be away. Many had concerns for family and employment situations at home. Many were serving in piecemeal units, assembled just for the deployment. Living conditions were less than ideal, depriving them of privacy and relaxation. They were the first warriors since World War I knowingly sent into a battle area where chemical and biological threats were expected. They also had free access to a media blitz that openly speculated on potential casualty counts before the fighting even began. When you compound these factors with the stresses of combat, and the environmental considerations, you are talking about an extended, high-stress environment. We need to understand exactly what this did to our people."

Another observation of the RAND study is that Gulf War stress factors may be particularly long-lived due, in part, to the enormous amount information, both accurate and erroneous, in public circulation. The prevalence of information from the media has served to boost public awareness, as well as speculation, as to the reasons for Gulf War illnesses.

"A veteran or family member seeking information about Gulf War illnesses can be overwhelmed by the amount of information out there," Rostker said. "Some of it is quite frightening. It's not always easy to tell what's credible and what isn't. Just trying to sort it all out is likely to raise stress levels, especially when we're talking about a sick veteran."

RAND researchers noted in their report that the scientific investigation of stress has made significant advances in recent years. General research, not specifically targeted at Gulf War medical issues, offers considerable evidence of the links between stress and illness. Stress is considered a possible causal factor of numerous physical symptoms and is generally thought to play a modest role in increasing the likelihood of developing a range of physical illness and disease, including cardiovascular disorders.

Psychological disorders, notably Post Traumatic Stress Disorder, have been positively linked with exposure to stressful events. A small percentage of Gulf War veterans suffer from diagnosed PTSD. The RAND research also reveals that certain groups are more susceptible to the psychological effects of high levels of stress. These individuals may be more vulnerable due to genetic or biological predisposition, prior life experiences, or personal and social coping resources. Data collected by military mental health professionals before, during, and after the Gulf War supports this observation.

According to RAND, the available literature also suggests that the psychological and physical symptoms recede in time for most affected individuals, but sometimes the symptoms persist long after the stressful event. Delayed onset of symptoms many years after the event is not unknown; however, recent research suggests that delay in seeking medical help may be responsible for some of these cases. Early symptoms may either be ignored or are mild enough to be dismissed until conditions worsen and the individual seeks help.

The RAND literature study confirms that the patterns of illness in Gulf War veterans closely parallel those of general populations examined for the effects of stress in many scientific studies.

"From this we can draw some useful inferences to direct our continuing investigations on the role stress in Gulf War illnesses." Rostker said. "The RAND study serves best as an identification tool and point of departure for current Gulf War medical investigations. Currently the federal government supports 140 medical research studies related to illnesses in Gulf War veterans. Many of these studies focus on the physical and psychological effects of exposure to stress."

The RAND report observes that a serious problem still exists with popular perceptions of stress. In many instances, stress as an explanation of poor health casts an unfair stigma on the afflicted. Unfortunately, the undeserved social stigma associated with stress has led some individuals to avoid seeking proper medical care. There is also a perception that if stress exposure were assigned any role in the health problems of Gulf War veterans, a failure to vigorously pursue other possible causes would result.

"Our veterans are experiencing real symptoms and real suffering regardless of the cause," said Rostker. "We cannot ignore any potential sources of illness in our investigations and that includes the effects of stress. Be assured, we are totally dedicated to providing the best care for our service members and veterans, now and in the future."

The RAND Corporation is a nonprofit institution working to help improve policy and decision making through research and analysis. Rostker says RAND's 50 years of research experience and long-time association with the Department of Defense eminently qualify the corporation to carry out this type of research. The literature was reviewed by RAND experts, including Dr. Grant Marshall, a clinical psychologist and an expert in psychometric evaluation and multivariate data analysis; Dr. Lois Davis, a health policy analyst and an expert in military medical readiness and mental health policy; and Dr. Cathy Donald Sherbourne, a medical sociologist and an expert in health outcome measurement.

Literature reviews covering pesticides, pyridostigmine bromide, immunizations, infectious diseases, vaccines, and chemical and biological weapons are being prepared and will be released in coming months. The RAND study on oil well fires was released last November and RAND evaluations of depleted uranium and investigational new drugs were released on April 15th.

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