Psychiatric morbidity due to service during the Gulf War was predicted to be low for several reasons: the short duration of the conflict, the relatively low casualties sustained by American forces, and the positive support for the war at home. Examination of records of evacuation during the conflict is one approach to examining the extent of psychiatric morbidity: the Army rate of evacuation for psychiatric reasons translated to only 2.7 per 1,000 evacuations per year. This very low rate of psychiatric evacuations is in contrast to prior wars in which evacuations for psychiatric disorders in comparison to total evacuations were: 23% in World War II, 10% for Korea, and 7% from Vietnam. Of the roughly 250 Army personnel evacuated from the Gulf for psychiatric reasons, approximately fifty (20%) were later determined to be disabled for further military service; levels of Post Traumatic Stress Disorder (PTSD2) were found to be very low, with only four of these 50 carrying a diagnosis of PTSD . Another approach to assessing psychiatric morbidity possibly relating to service in the Gulf is to examine the numbers of service members referred for disability determination due to psychiatric disorders. As of March 1994, approximately 294 soldiers with psychiatric-related diagnoses were referred for disability determinations. Of these, 112 carried the diagnosis of PTSD. There are several studies in the literature which report on the prevalence of psychiatric disorders and stress symptoms during and following the Gulf
War    [3l]  [/dsbrpt/33] . However, it is difficult to generalize from these papers because of the unique characteristics of the populations studied.
Studies from the Veterans Administration have shown somewhat higher levels of PTSD. A preliminary report estimated a prevalence of PTSD at roughly 9%. Of note is that 34% appeared to have experienced other forms of significant psychological distress upon return.
In the initial phase of the ODS Veterans Survey spanning from October 15, 1991, to April 15, 1992, 1006 surveys were completed; roughly one-half at VA centers, and one-half at outreach locations. A composite PTSD measure was created on the basis of random structured psychiatric telephone interviews and their relation to the completed survey. At the initial survey, PTSD levels were found to be 36.5% for veterans seeking psychological treatment at Vet Centers ("treatment-seeking"), 4.9% for those veterans seeking other services at Vet centers ("service-seeking"), and 5.3% for veterans who completed the survey at an outreach location ("non-service-seeking"). At the six month follow-up (April 15 -- October 15, 1992), treatment-seeking veterans exhibited less PTSD at follow-up (19.4% compared to 37.1%) . The non-service-seeking veterans exhibited more PTSD (7.6% versus 5.4% at Time l) and the service-seeking veterans exhibited twice the level of PTSD (9.8% versus 4.9%.)
The prevalence of psychiatric conditions in veterans enrolled in the active duty and VA registries for Desert Storm-related conditions appears to be modest. Inpatient primary psychiatric diagnoses in Persian Gulf veterans showed 34.7% suffering from mental disorders; 11.6% from alcohol dependence; 5.1% from drug dependence and 6.1 % from adjustment disorders (including PTSD) . Of the 67 individuals enrolled in the Navy Gulf War registry in February 1994, 6 were listed as having a psychiatric condition as their major complaint (l adjustment disorder with depressed features; 1 major depression; 4 PTsD)[4l]. Approximately 7 other individuals carried associated or incident psychiatric diagnoses (3 depressive disorders, 2 PTSD, 1 adjustment disorder and 2 personality disorders). Of the 149 individuals enrolled in the Army's Gulf Syndrome Registry as of February 1994, 12 were listed as having presumed or confirmed PTSD; 4 suffered depressive disorders; 2 panic disorders; 1 bipolar disorder. Similarly, a group of 78 veterans complaining of symptoms of fatigue was found to have a low prevalence of psychiatric disorders (@12%).
B. Historical Background
Appreciation for the role of situational stress as a major military medical problem began in the latter half of the l9th century and paralleled the development of psychiatry as a medical specialty. During the Civil War, DaCosta attributed a syndrome consisting of generalized weakness to an irritable and exhausted heart. A similar constellation of symptoms was described as neurocirculatory asthaenia during World War I. Physicians in the past have attempted to understand the etiology of these syndromes. As in today's discussion of complex illnesses, there was much controversy surrounding the relative contribution of "organic" (medical) versus "functional" (psychological) factors.
In current military psychiatry the term acute stress reaction or battle fatigue is applied to a wide range of somatic (physical) and psychological responses in the combat theater. When military psychiatric principles of proximity, immediacy and expectancy are employed, the vast majority of these casualties can be returned to duty.
Numerous studies have demonstrated that participating in combat is related to an increase in nonsurgical illness . Much less is known about the longer term medical and psychological consequences of going to war (See Rundell and Ursano for review). Vietnam veterans reported many more physical symptoms and illnesses than did military contemporaries not serving in combat; 25% more Vietnam veterans sought medical care for health problems than did non-combat veterans. Vietnam veterans were almost twice as likely to describe their health as "fair" or "poor" in comparison with veterans during that time period who did not serve in Vietnam (19.6% versus 11.1%). It is of note that physical examinations and laboratory studies found few differences between these two groups.
In looking at the general literature on the relationship of exposure to trauma and subsequent health, numerous investigators have noted a relationship between Post-Traumatic Stress Disorder (PTSD) and somatic complaints. For example, 5 out of 9 firefighters with chronic PTSD presented to their physicians with somatic complaints that distracted attention from the underlying PTSD. High amounts of PTSD symptomatology were found to correlate with reports of high amounts of physical health problems in veterans. Similar relationships between PTSD in Vietnam combat-veterans and increased reporting of health complaints were also found by Litz et al. These investigators noted those health complaints in the veterans with PTSD clustered around symptoms suggestive of sympathetic hyperactivity, especially gastrointestinal and cardiopulmonary complaints. Health complaints were found to correlate positively to severity of PTSD. The presence of physician-diagnosed medical conditions did not differentiate between combat veterans with and without PTSD. In a study of Israeli combat veterans, the 50 veterans with PTSD reported significantly more symptoms than did age-matched combat veterans without PTSD. However, the veterans with PTSD did not differ from the controls in findings on physical examination or laboratory evaluation. Solomon and colleagues found that one, two, and three years after their participation in the Lebanon war, Israeli combat veterans who had experienced combat stress reactions during the war reported significantly more health problems.
C. Relationship Between War-Related Stress and Health
The relationship between exposure to war-related stress and long-term effects on health is not well understood. Various hypotheses have been advanced to explain the ways in which stress can affect health (see Litz et al for a review of proposed mechanisms). Recent attention has turned to the effects of stress on the endocrine and immune systems,,.
In terms of the Persian Gulf War, several studies have found that deployed veterans reported more somatic complaints than did non-deployers. In a study of Desert Storm veterans from New England, in a survey taken 18 months after their return from the Gulf, 32.4% of all respondents reported that their health had changed for the worse since their homecoming. Higher endorsement of symptoms was found in subjects who exceeded clinical cutoffs for PTSD: mean numbers of health problems in this group were nearly triple those of the other soldiers. The 3 most commonly endorsed health problems were general aches and pains, headaches, and a lack of energy.
In a sample of 4334 veterans from Hawaii and Pennsylvania, of whom 1739 deployed to the Persian gulf, both the active duty and reserve sample of deployers were significantly more likely to report higher levels of almost all symptoms, often at rates of two-to-one.
The relationship between self-report of symptoms and diagnoses of PTSD based on questionnaire cut-off scores must be interpreted cautiously however. In a multiphase study on the physical and psychosocial impact of activation and deactivation on Army Reserve nurses who did not deploy to the Gulf, over half endorsed PTSD symptoms of intrusion in the high range and about two-third endorsed high avoidance symptoms[6l]. Given the low casualties sustained during the war and the fact that these nurses were not in the combat theater, it is unlikely that these scores reflect traditional war-related stressors per se. Somatic complaints were endorsed at a high rate by this group with over half complaining of headaches. Sleep disturbance, sore muscles, nausea, and lower back pains were also reported to be common.
The positive correlation between PTSD and health complaints suggests that Desert Storm veterans with PTSD are at higher risk for complaints of health problems. In Vietnam veterans, the National Vietnam Veterans Readjustment Study (NVVRS) found that 15.2% of the male and 8.5% of the female Vietnam theater veterans suffered from PTSD at the time of the survey. In terms of forecasting rates of PTSD from the Gulf War, it may be more instructive to examine the Israeli experience following the 1982 Lebanon War, a war lasting a matter of weeks rather than years. It is important to note that 14% of combat veterans who had not displayed acute stress reactions during combat met diagnostic criteria for PTSD one year after the war.