REVIEW:
War Syndromes and Their Evaluation: From the U.S. Civil War to the Persian Gulf War

Kenneth C. Hyams, MD, MPH¹
F. Stephen Wignall, MD²
Robert Roswell, MD³

¹U.S. Naval Medical Research Institute, Bethesda, Maryland
²U.S. Naval Medical Research Unit No.2, Jakarta, Indonesia
³Department of Veterans Affairs, Bay Pines, Florida

The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or reflecting the views of the U.S. Navy, Department of Defense, or Department of Veterans Affairs.

Abstract

Purpose: To better understand the health problems of veterans of the Persian Gulf War by analyzing previous war-related illnesses and identifying possible unifying factors.

Data Source: English-language articles and books on war-related illnesses published since 1863 that were located primarily through a manual search of bibliographies.

Data Extraction: Publications were assessed for information on the clinical characteristics of war-related illnesses and the research methods used to evaluate such illnesses.

Data Synthesis: Poorly understood war syndromes have been associated with armed conflicts at least since the U.S. Civil War. Although these syndromes have been characterized by similar symptoms (fatigue, shortness of breath, headache, sleep disturbance, forgetfulness, and impaired concentration), no single recurring illness that is unrelated to psychological stress is apparent. However, many types of illness were found among evaluated veterans, including well-defined medical and psychiatric conditions, acute combat stress reaction, post-traumatic stress disorder, and possibly the chronic fatigue syndrome. No single disease is apparent, but one unifying factor stands out: A unique population was intensely scrutinized after experiencing an exceptional, life-threatening set of exposures. As a result, research efforts to date have been unable to conclusively show causality, have been subject to reporting bias, and have lacked similar control populations. In addition to research limitations, war syndromes have involved fundamental, unanswered questions about the importance of chronic somatic symptoms and the factors that create a personal sense of ill health.

Conclusion: Until we can better understand what constitutes health and illness in all adult populations, we risk repeated occurrences of unexplained symptoms among veterans after each war.

Introduction

After returning home in 1991, some veterans of the Persian Gulf War began reporting diverse symptoms that have been collectively called a mystery illness or the Gulf War syndrome (1). Extensive programs have been initiated by the governments of the United States, Great Britain, and Canada to provide medical care for veterans of the Persian Gulf War, to define any new syndrome, and to determine the causes of the veterans' illnesses (2-4). In the search for the cause of a previously uncharacterized complex of signs and symptoms (or syndrome), the question arises whether a similar illness occurred during or after previous wars. If an analogous illness affected veterans of other wars, its cause may be related to common wartime experiences rather than to a unique event during the Persian Gulf War. In this historical review, war-related syndromes from the U.S. Civil War to the Persian Gulf War were analyzed to identify possible unifying factors.

War Syndromes

U.S. Civil War
During the U.S. Civil War, Da Costa (5) did one of the first studies of a war syndrome. Da Costa evaluated 300 soldiers referred to him for a syndrome that he called irritable heart; this syndrome was principally characterized by shortness of breath, palpitations, and sharp or burning chest pain, particularly on exertion. Other symptoms included fatigability, headache, diarrhea, dizziness, and disturbed sleep (Table 1). There was no consistent sign of physiologic disease, and most patients appeared to be in fair overall health.

Symptoms of the irritable heart syndrome were not restricted to soldiers who had been in combat, and Da Costa believed that the condition occurred in civilian populations. Because many of the patients had had a recent episode of diarrhea, upper respiratory infection, or febrile disease, Da Costa concluded that an infectious disease was the cause in 48% of patients. Thirty-five percent of cases were attributed to strenuous military duties and 18% to miscellaneous causes. Da Costa reported that 38% of patients recovered from the disorder and that administration of several drugs, including digitalis, may have had a beneficial effect.

On the basis of Da Costa's clinical descriptions, it is difficult to confidently determine specific diagnoses; however, various illnesses could have caused the symptoms in these patients (6, 7). Few patients had conclusive evidence of heart disease. Many patients were debilitated from malnutrition, lack of exercise, infectious diseases (including malaria and typhoid), and other adverse medical conditions. Some patients had symptoms of a psychological illness or stress reaction (8).

In addition to the irritable heart syndrome, a war-related illness attributed primarily to psychological factors was reported during the U.S. Civil War. Young soldiers with obsessive thoughts of home received a diagnosis of a severe form of homesickness called "nostalgia," which was characteristically accompanied by extreme apathy, loss of appetite, diarrhea, and sometimes fever (9, 10).

World War I
A syndrome similar to the one described by Da Costa became a major problem during World War I: Soldiers had to be evacuated to England because of shortness of breath, palpitations, and chest pain (11). Affected soldiers also commonly reported fatigue, headache, dizziness, confusion, concentration problems, forgetfulness, and nightmares (Table 1) (12-14). This complex of symptoms became known as soldier's heart or the effort syndrome because symptoms were exacerbated by effort. It was also called the Da Costa syndrome, disordered action of the heart, and, in the United States, neurocirculatory asthenia (15).

At the beginning of World War I, the effort syndrome was frequently attributed to cardiac hypertrophy caused by heavy marching packs compressing the chest (16, 17). However, as the war progressed, the effort syndrome was believed to encompass a mixed group of illnesses and causes, including constitutional nervous weakness and physical weakness; an infectious disease or debility from previous infections; exhaustion from lack of sleep and exertion in the trenches; the effects of poison gas; malingering; and, rarely, heart disease (12-14, 18-23). In some cases, onset of symptoms was also associated with acute stress resulting from combat or burial duties (12, 22).

Digitalis and other drugs did not benefit patients with the effort syndrome, but a structured rehabilitation program with a graduated exercise regimen and encouragement from a supervising medical staff were effective (12, 22). It was also found that if symptoms of the effort syndrome were attributed to heart disease, recovery and return to duty were hindered (12, 13). As a result, physicians were advised not to tell soldiers that they had a heart condition so that the soldiers would not think of themselves as patients who required evacuation from the front (12, 21, 22, 24).

A concerted clinical and research program was developed during World War I to determine the causes and most effective treatment of the effort syndrome (11). This program involved clinical care and empirical observations in two specialized hospitals in England (12) and a specialized referral center in the United States (7, 17). After the war, the Medical Research Council continued to oversee clinical evaluation and additional studies for the British government (11). Further investigations were given high priority because the effort syndrome was the third most common reason for disability and compensation assessment in England; 44 000 veterans eventually received pensions for this condition (11, 14, 25).

Although clinical studies published at the end of the war (26-28) indicated that the effort syndrome was caused by psychological factors, there was little agreement on what specific symptoms constituted the effort syndrome, whether it was primarily a physiologic or psychological illness, and even what the official name of the condition should be (29). However, there was a consensus that the effort syndrome was not caused exclusively by unique wartime exposures, because many soldiers reported having had similar symptoms before the war (12, 19, 22).

Each year for 5 years after World War I, a survey was mailed to 601 British veterans who had received a diagnosis of the effort syndrome and who had received pensions (30). Data from this survey and available medical records identified 52 veterans who had developed various defined illnesses, including 22 cases of pulmonary tuberculosis and 6 confirmed cases of cardiac disease. The health of most other veterans had remained stable, and mortality did not increase.

In addition to the effort syndrome, an acute illness attributed to combat stress (which was called shell shock or trench neurosis) was investigated during World War I. This acute combat stress reaction was first attributed to a strange new disease, possibly caused by concussion from modern weapons; however, a psychological cause was soon determined (31, 32). Typical manifestations of acute combat stress reaction included breakdown in battle, dazed or detached manner, exaggerated startle response, and severe anxiety (32, 33).

During World War I, it was determined that soldiers with shell shock could be rapidly rehabilitated if they were cared for near the front, expecting a quick recovery (32). After soldiers with shell shock were taken away from their comrades and treated as patients in a hospital, they were much less likely to return to combat. Also, the British used the nonspecific term "not yet diagnosed, nervous (NYD)" for the initial designation of possible victims of shell shock; this designation prevented soldiers from concluding that they had a medical condition that required hospitalization (32, 33).

World War II
At the beginning of World War II, the effort syndrome again became an important medical consideration for the British military (14). Whether the effort syndrome was predominantly a physiologic or psychological illness had not been resolved (14, 34). However, after Wood's influential clinical studies of 200 patients (35-37), the effort syndrome was generally considered to be a psychoneurosis and not a medical disease (7).

Acute combat stress reaction (which was known as battle fatigue, combat exhaustion, or operational fatigue among aviation personnel during World War II) also became better understood at this time (33, 38). Studies of combat personnel determined that acute combat stress reaction frequently manifested as somatic symptoms, including fatigue, palpitations, diarrhea, headache, impaired concentration, forgetfulness, and disturbed sleep (Table 1) (39).

As in World War I, soldiers with acute combat stress reaction were more likely to return to duty if they were treated quickly and near their combat units and received a diagnosis of a normal response to extreme stress rather than an abnormal condition. Consequently, use of such diagnostic labels as "war neurosis" was discouraged because they connoted that soldiers were sick and should be treated as patients (33, 39, 40).

Korean Conflict
Possibly because the effort syndrome had been attributed to psychological causes during World War II, it was not reported as a major medical problem during the Korean Conflict (7). Since the 1940s, the effort syndrome has been identified less frequently as a unique disease entity (41-43), but the lineages of many illnesses not related to war have been traced back through the effort syndrome to the Da Costa syndrome. Such illnesses include anxiety neurosis and manic-depressive conditions (44), panic disorders (45), the mitral valve prolapse syndrome (17, 46), the hyperventilation syndrome (47), and the chronic fatigue syndrome(48).

As in World War I and World War II, acute combat stress reaction was an important clinical problem during the Korean Conflict (33, 38).

Vietnam War
The most prominent illness related to the Vietnam War was post-traumatic stress disorder (49), which was initially called post-Vietnam syndrome (50, 51). Whereas acute combat stress reaction is the immediate consequence of psychological trauma, post-traumatic stress disorder more often refers to the long-term consequences of extreme psychological stress (52). Post-traumatic stress disorder has also been recognized as a problem in veterans of both the Korean Conflict and World War II (53), especially former prisoners of war (54, 55), and has been found in civilians exposed to extreme trauma not related to war (51).

No other prominent, poorly understood war syndrome was associated with the Vietnam War (56-58), although controversy about the role of Agent Orange (dioxin) exposure in the development of various medical problems and birth defects continues (59). Chronic somatic symptoms have generally not been linked to the effects of herbicide exposure in Vietnam. However, it is noteworthy that the somatic symptoms frequently described by Vietnam veterans who may have been exposed to Agent Orange (56, 58, 60) are similar to the symptoms commonly associated with other war-related illnesses (61), including acute combat stress reaction (39) and post-traumatic stress disorder (62-68) (Table 1).

Persian Gulf War
After Iraq invaded Kuwait in August 1990, 697 000 soldiers from the United States, 45 000 soldiers from Great Britain, and 4500 soldiers from Canada were deployed to the Persian Gulf during a 5-month buildup period; this period was followed by a 39-day air war and a 4-day ground war in February 1991. Far fewer casualties than anticipated occurred among coalition forces, and morbidity rates were low compared with those in previous wars (69, 70).

After the war ended, troops returned home, and veterans from diverse military units of the United States, Great Britain, and Canada began reporting various chronic symptoms, often referred to as the Gulf War syndrome (71-77). Fatigue, headache, muscle and joint pain, diarrhea, skin rashes, shortness of breath, and chest pain have been common symptoms (Table 1) (2, 78-80). Various neuropsychological symptoms also have been common -- particularly sleep disturbances, impaired concentration, forgetfulness, irritability, and depression. Currently, no characteristic physical sign or laboratory abnormality has been identified (2, 80, 81).

No medical reports of similar unexplained illnesses among other coalition troops or among persons indigenous to the Persian Gulf have been published. During World War II, no similar unexplained illnesses were seen among the British and U.S. forces stationed in the Persian Gulf (82).

Personal accounts of family members developing symptoms similar to those of relatives who served in the Persian Gulf War and increased birth defects among children born after the war have been reported (2, 83). Other recent war-related conditions have been associated with medical and psychological problems among family members (59, 84), but accounts of health problems among family members of veterans who received a diagnosis of a war-related illness did not increase during World War I or World War II.

The health problems experienced by veterans after service in the Persian Gulf War have been considered a serious matter by the involved governments, a response similar to that seen for the effort syndrome in World War I. A tri-agency coordinating board has been established in the United States to supervise a comprehensive clinical and research program (85-87), and compensation is being provided to disabled war veterans who have unexplained illnesses (U.S. Public Law 103-446, 2 November 1994). In addition, the U.S. Department of Veterans Affairs, the U.S. Department of Defense, and the governments of Great Britain and Canada have established self-referred health registries and specialized centers that provide comprehensive clinical examinations and medical care (2-4).

Clinical evaluation of more than 80 000 veterans and initial epidemiologic surveys have identified a broad range of health problems (2, 80, 88, 89), including symptoms of post-traumatic stress disorder in 5% to 15% of some veteran populations (90-94); however, a new or unique syndrome has not yet been identified (80). Preliminary results of epidemiologic studies of veterans of the Persian Gulf War show no overall increase in hospitalization rates (95), birth defects (96), or mortality due to medical causes (97).

Available information on the nature and cause of illnesses among veterans of the Persian Gulf War has been evaluated by five independent panels in the United States (70, 98-101). These panels did not identify a new illness (70, 98, 100) or establish a case definition of a unique syndrome (70, 98, 99, 101); they concluded that veterans of the Persian Gulf War had numerous illnesses that resulted from various causes (70, 98). However, one advisory committee concluded that a rare or mild illness could be missed by large case series, such as the Persian Gulf health registries, which have examined approximately 10% of all U.S. veterans of the Persian Gulf War (100).

Comparison of War Syndromes

Since the U.S. Civil War, two general categories of war-related illnesses have been recognized: one poorly understood group thought to be associated with physiologic disease and another group of psychological illnesses attributed to wartime stress (Table 2). Although there have been two general types of war-related illnesses, war syndromes have not been consistently defined or identified by a pathognomonic physical sign or laboratory abnormality. As a result, the diagnosis of a physiologic or psychological illness in individual patients has been imprecise and has depended on self-reported symptoms and the impression of the examining physician (8, 13, 34, 61, 98).

The war syndromes thought to be associated with organic pathology have been characterized by two similarities that could indicate a related disease. From the Da Costa syndrome to the more recent Gulf War syndrome, the first common feature has been the similarity of reported symptoms. Shared symptoms include fatigue, shortness of breath, headache, sleep disturbances, impaired concentration, and forgetfulness (Table 1). Common symptoms alone, however, do not show that veterans of various wars had a related disease process, because such symptoms are nonspecific and are frequently found in all adult populations (102-106), particularly among persons with psychological stress (39, 56, 107) and post-traumatic stress disorder (62, 63, 108).

A second possible unifying factor has been the high frequency of reported diarrhea and other infectious diseases preceding the onset of these syndromes (5, 13, 19, 109). The significance of this factor is unclear because crowded populations of military personnel, particularly troops sent to tropical and developing regions, have an inevitably high rate of infectious disease (58, 82). However, no unique, deployment-related syndrome has been reported after large peacetime military exercises. In addition, infectious diseases have not been proven to cause chronic somatic symptoms in the absence of measurable signs of disease (110), except possibly among persons prone to depression (111, 112). Nevertheless, convalescence can be prolonged after many infections (113), and the chronic fatigue syndrome, although not associated with characteristic signs of disease, is suspected of having an infectious origin (114).

Other than these two similarities, there is little additional evidence of a single, unique war syndrome that is unrelated to psychological stress. However, 19th-century and early 20th-century clinical characterizations are difficult to compare with modern data, and the psychological aspects of illness were not as well appreciated and reported in the past. Furthermore, because of the general improvement in health and nutrition during this century, it is difficult to compare the illnesses of military populations of different eras.

Although historical data are difficult to compare, ample evidence shows that numerous complex factors were responsible for the health problems of war veterans, as in any population, and that many illnesses were described after successive wars. A substantial proportion of veterans with chronic somatic symptoms were found to have various physiologic and psychological illnesses (13, 30, 80, 89). In addition, veterans of each war had high rates of acute combat stress reaction and post-traumatic stress disorder (33). Still other veterans had illnesses that meet the recently suggested criteria for a diagnosis of the chronic fatigue syndrome (48, 70, 89, 115).

Although no single, recurring war-related disease has been identified, many aspects of the process used during the past 130 years to evaluate the health problems of veterans have been repeated with each war. The most important and consistent factor is that this process has involved medical evaluation after the critical event, thereby precluding a definitive demonstration of causality. Consequently, numerous illnesses that occur after a war may be attributable to wartime exposure, and epidemiologic studies, regardless of their size or design, cannot conclusively resolve medical, legal, and political questions about the causes of post-war health problems (116). In addition to the problems of interpreting the results of retrospective studies, it has been difficult to identify similar control populations because of the exceptional nature of wartime experiences and the unique characteristics of military populations.

Because studies of war-related illnesses have been done after exposure and without similar control groups, research efforts have frequently been limited to the evaluation of a series of clinical cases. Research efforts have been further hampered because war syndromes have not been associated with characteristic and measurable signs of disease that would allow for the development of specific case definitions (8, 98). In addition to these research limitations, the problem of diagnostic labeling has played a critical role in the evaluation of war syndromes. The naming of a syndrome has repeatedly exerted a powerful effect on the medical approach toward, official recognition of, and patient perception of these poorly understood conditions (11, 33). A medically recognized diagnosis fundamentally alters the lives of active-duty military personnel and veterans, influencing everything from type and location of duty assignment to medical treatment, expectations of recovery, and eligibility for compensation (13, 37). The influence of a medical classification has also been found to be substantial among nonmilitary populations (117-119).

Conclusions

Despite enormous progress in medical science, poorly understood war syndromes have recurred at least since the U.S. Civil War. No single, previously uncharacterized illness or underlying cause that is unrelated to psychological stress is apparent from the available reports. However, many illnesses have been found among war veterans evaluated for these syndromes. As expected in any large adult population exposed to complex environmental and psychological conditions, various health problems have developed.

Although no unique war-related disease is evident, one unifying factor has been prominent in the evaluation of these syndromes: A unique population was intensely scrutinized after experiencing an exceptional, life-threatening set of exposures. The process by which these syndromes were evaluated and defined is the most evident similarity.

Designing studies to evaluate the health of war veterans inevitably presents several serious methodologic problems (116). For example, it is difficult to obtain accurate health and risk factor data after a potentially harmful experience, particularly if there has been extensive or sensational media coverage, because of reporting bias (120-122). During wartime conditions, it is not feasible for the military to collect comprehensive exposure data among combat troops because the primary focus must be to fight and win the war.

An apparent solution to these methodologic problems is to gather more extensive baseline medical and exposure data and to design large prospective studies before any future conflict. As a result of numerous recent overseas deployments, the U.S. Department of Defense is developing a greatly enhanced surveillance system. For military operations in Bosnia, which began in 1995, environmental and infectious disease surveillance teams have been deployed; U.S. troops are being provided extensive health guidance before, during, and after the operation; medical and psychological screening will occur before and after deployment; and a repository for serum collected before and after deployment is being established (123).

Intensive surveillance will substantially aid in the evaluation of veterans' health. However, it will be difficult to design prospective studies to answer all post-war health questions because the location and nature of each war varies too greatly to predict every health risk. In addition, studies of military populations alone will not sufficiently explain war-related syndromes because these syndromes involve fundamental, unanswered questions about health and illness. To more fully understand the health of any population, military or civilian, research efforts will have to be done to answer two basic questions: 1) What is the relation between chronic, non-specific symptoms and physiologic and psychological illness (124-127)? 2) What factors -- medical, environmental, psychological, or social -- create a personal sense of ill health (128-131)?

Evaluating fundamental questions of health in large populations is always extraordinarily difficult, but is particularly so after traumatic and complex wartime events. Nevertheless, unless these difficult questions are answered, we risk repeated occurrences of unexplained symptoms among veterans after each war.

This work was supported by the U.S. Naval Medical Research and Development Command, NMC, NCR, Bethesda, MD.

References

1. Cotton P. Veterans seeking answers to syndrome suspect they were goats in Gulf War
   [News]. JAMA. 1994;271:1559-61.
   
   
2. Unexplained illnesses among Desert Storm veterans. A search for causes, treatment, and cooperation. Persian Gulf Veterans Coordinating Board. Arch Intern Med. 1996;155:262-8.
   
   
3. Bridging the Gulf [Editorial]. Lancet. 1996;347:341.
   
   
4. Robinson A. Veterans worry that unexplained medical problems a legacy of service during Gulf War. Can Med Assoc J. 1995;152:944-7.
   
   
5. Da Costa JM. On irritable heart: a clinical study of a form of functional cardiac disorder and its consequences. Am J Med Sci. 1871;61:17-52.
   
   
6. Jarcho S. Functional heart disease in the Civil War (Da Costa, 1871). Am J Cardiol. 1959;4:809-17.
   
   
7. Paul O. Da Costa's syndrome or neurocirculatory asthenia. Br Heart J. 1987;58:306-15.
   
   
8. Ettedgui E, Bridges M. Posttraumatic stress disorder. Psychiatr Clin North Am. 1985;8:89-103.
   
   
9. Hammond WA. A Treatise on Insanity in Its Medical Relations. New York: Appleton; 1883:411-5.
   
   
10. Peters DC. Remarks on the evils of youthful enlistments and nostalgia. American Medical Times. 1863;6:75-6.
    
    
11. Howell JD. Soldier's heart: the redefinition of heart disease and specialty formation in early twentieth-century Great Britain. Med Hist Suppl. 1985;5:34-52.
    
    
12. Lewis T. Report on neuro-circulatory asthenia and its management. Military Surgeon. 1918;42:409-26.
    
    
13. Lewis T. The Soldier's Heart and the Effort Syndrome. New York: P.B. Hoeber; 1919.
    
    
14. Lewis T. The Soldier's Heart and the Effort Syndrome. 2d ed. London: Shaw; 1940.
    
    
15. Jarcho S. Harlow Brooks on neurocirculatory asthenia in World War I. Am J Cardiol. 966;18:892-7.
    
    
16. MacLean WC. Diseases of the heart in the British army: the cause and the remedy. Br Med J. 1867;1:161-4.
    
    
17. Wooley CF. From irritable heart to mitral valve prolapse: British army medical reports, 1860 to 1870. Am J Cardiol. 1985;55:1107-9.
    
    
18. Cotton T, Lewis T, Thiele FH. A note on the "irritable heart" of soldiers. Br Med J. 1915;1:722.
    
    
19. MacKenzie J. The soldier's heart. Br Med J. 1916;1:117-9.
    
    
20. Parkinson J. The cardiac disabilities of soldiers on active service. Lancet. 1916;2:133-8.
    
    
21. Abrahams A. Soldier's heart. Lancet. 1917;1:442-5.
    
    
22. Hume WE. A study of the cardiac disabilities of soldiers in France. Lancet. 1918;1:529-34.
    
    
23. Venning JA. The etiology of disordered action of the heart: a report on 7,803 cases. BMJ. 1919;2:337-9.
    
    
24. Rudolf RD. The irritable heart of soldiers (soldier's heart). Can Med Assoc J. 1916;6:796-810.
    
    
25. Work of the Pensions Ministry. BMJ. 1922;1:68.
    
    
26. MacIlwaine JE. A clinical study of some functional disorders of the heart which occur in soldiers. J R Army Med Corps. 1918;30:357-77.
    
    
27. Cohn AE. The cardiac phase of the war neuroses. Am J Med Sci. 1919;158:453-70.
    
    
28. Culpin M. The psychological aspect of the effort syndrome. Lancet. 1920;2:184-6.
    
    
29. Siler JF. The Medical Department of the United States Army in the World War. v 9. Communicable and Other Diseases. Washington, DC: U.S. Government Printing Office; 1928.
    
    
30. Grant RT. Observations on the after-histories of men suffering from the effort syndrome. Heart. 1925;12:121-42.
    
    
31. Mott FW. The effects of high explosives upon the central nervous system. Lancet. 1916;1:331-8.
    
    
32. Salmon T, Fenton N. The Medical Department of the United States Army in the World War. v 10. Neuropsychiatry. Washington, DC: U.S. Government Printing Office; 1929.
    
    
33. Kentsmith DK. Principles of battlefield psychiatry. Mil Med. 1986;151:89-96.
    
    
34. Fraser FR. Effort syndrome in the present war. Edinburgh Medical Journal. 1940;47:451-65.
    
    
35. Wood P. Da Costa's syndrome (or effort syndrome). BMJ. 1941;1:767-72.
    
    
36. Wood P. Da Costa's syndrome (or effort syndrome): the mechanism of the somatic manifestations. BMJ. 1941;1:805-11.
    
    
37. Wood P. Aetiology of Da Costa's syndrome. BMJ. 1941;1:845-51.
    
    
38. Glass AJ. Psychotherapy in the combat zone. Am J Psychiatry. 1954;110:725-31.
    
    
39. Grinker RR, Spiegel JP. Men Under Stress. Philadelphia: Blakiston; 1945:82-117, 208-24, 251-77.
    
    
40. Armfield F. Preventing post-traumatic stress disorder resulting from military operations. Mil Med. 1994;159:739-46.
    
    
41. Cohen ME, White PD, Johnson RE. Neurocirculatory asthenia, anxiety neurosis or the effort syndrome. Arch Intern Med. 1948;81:260-81.
    
    
42. Newham D, Edwards RH. Effort syndromes. Physiotherapy. 1979;65:52-6.
    
    
43. Nixon PG. The grey area of effort syndrome and hyperventilation: from Thomas Lewis to today. J R Coll Physicians Lond. 1993;27:377-83.
    
    
44. Cohen ME, White PD. Neurocirculatory asthenia: 1972 concept. Mil Med. 1972;137:142-4.
    
    
45. Rudzki SJ. Soldier's heart [Letter]. Med J Aust. 1984;141:766-7.
    
    
46. Wooley CF. Where are the diseases of yesteryear? DaCosta's syndrome, soldiers heart, the effort syndrome, neurocirculatory asthenia--and the mitral valve prolapse syndrome. Circulation. 1976;53:749-51.
    
    
47. Dalessio DJ. Hyperventilation. The vapors. Effort Syndrome. Neurasthenia. Anxiety by any other name is just as disturbing. JAMA. 1978;239:1401-2.
    
    
48. Straus SE. History of chronic fatigue syndrome. Rev Infect Dis. 1991;13(Suppl 1):S2-7.
    
    
49. Health status of Vietnam veterans. I. Psychosocial characteristics. The Centers for Disease Control Vietnam Experience Study. JAMA. 1988;259:2701-7.
    
    
50. Friedman MJ. Post-Vietnam syndrome: recognition and management. Psychosomatics. 1981;22:931-43.
    
    
51. Helzer JE, Robins LN, McEvoy L. Post-traumatic stress disorder in the general population: findings of the epidemiologic catchment area survey. N Engl J Med. 1987;317:1630-4.
    
    
52. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 1994.
    
    
53. Archibald HC, Tuddenham RD. Persistent stress reaction after combat. A 20-year follow-up. Arch Gen Psychiatry. 1965;12:475-81.
    
    
54. Kluznik JC, Speed N, Van Valkenburg C, Magraw R. Forty-year follow-up of United States prisoners of war. Am J Psychiatry. 1986;143:1443-6.
    
    
55. Sutker PB, Winstead DK, Galina ZH, Allain AN. Cognitive deficits and psychopathology among former prisoners of war and combat veterans of the Korean conflict. Am J Psychiatry. 1991;148:67-72.
    
    
56. Health status of Vietnam veterans. II. Physical health. The Centers for Disease Control Vietnam Experience Study. JAMA. 1988;259:2708-14.
    
    
57. Health status of Vietnam veterans. III. Reproductive outcomes and child health. The Centers for Disease Control Vietnam Experience Study. JAMA. 1988;259:2715-9.
    
    
58. Boyle CA, Decoufle P, O'Brien TR. Long-term health consequences of military service in Vietnam. Epidemiol Rev. 1989;11:1-27.
    
    
59. Veterans and Agent Orange: Health Effects of Herbicides Used in Vietnam. Washington, DC: National Academy Pr; 1994.
    
    
60. Bogen G. Symptoms in Vietnam veterans exposed to agent Orange [Letter]. JAMA. 1979;242:2391.
    
    
61. Holden C. Agent Orange furor continues to build. Science. 1979;205:770-2.
    
    
62. Egendorf A, Kadushin C, Laufer RS, Rothbart G, Sloan L. Long term stress reactions: some causes, consequences, and naturally occurring support systems. In: Legacies of Vietnam: Comparative Adjustment of Veterans and their Peers. v 4. New York: Center for Policy Research; 1981.
    
    
63. Solomon Z, Mikulincer M. Combat stress reactions, post traumatic stress disorder and somatic complaints among Israeli soldiers. J Psychosom Res. 1987;31:131-7.
    
    
64. Solomon Z. Somatic complaints, stress reaction, and posttraumatic stress disorder: a three-year follow-up study. Behav Med. 1988;14:179-85.
    
    
65. Shalev A, Bleich A, Ursano RJ. Posttraumatic stress disorder; somatic comorbidity and effort tolerance. Psychosomatics. 1990;31:197-203.
    
    
66. Sutker PB, Uddo-Crane M, Allain AN. Clinical and research assessment of posttraumatic stress disorder; a conceptual overview. Psychological Assessment. 1991;3:520-30.
    
    
67. Lindy JD, Green BL, Grace M. Somatic reenactment in the treatment of posttraumatic stress disorder. Psychother Psychosom. 1992;57:180-6.
    
    
68. Litz BT, Keane TM, Fisher L, Marx B, Monaco V. Physical health complaints in combat-related post-traumatic stress disorder. A preliminary report. J Trauma Stress. 1992;5:131-41.
    
    
69. Writer JV, DeFraites RF, Brundage JF. Comparative mortality among US military personnel in the Persian Gulf region and worldwide during Operations Desert Shield and Desert Storm. JAMA. 1996;275:118-21.
    
    
70. Report of the Defense Science Board Task Force on Persian Gulf War Health Effects, June 1994. Washington, DC: Office of the Undersecretary of Defense for Acquisition and Technology; 1994.
    
    
71. Brown D. Diagnosis unknown: Gulf War Syndrome. I. Triumphant in the desert, stricken at home. The Washington Post. 1994;Jul 24:A1
    
    
72. Brown D. Diagnosis unknown: Gulf War Syndrome. II. The search for causes. The Washington Post. 1994;Jul 24:A19.
    
    
73. McAllister B. Diagnosis unknown: Gulf War Syndrome. III. Compassion may take act of Congress; veterans agency balked at early response on Gulf War problem. The Washington Post. 1994;Jul 25:A1.
    
    
74. Brown D. Diagnosis unknown: Gulf War Syndrome. IV. Studies will frame a picture of Gulf veterans' problems. The Washington Post. 1994;Jul 25:A9.
    
    
75. Brown D. Diagnosis unknown: Gulf War Syndrome. V. Colonel loses ground to a faceless enemy. The Washington Post. 1994;Jul 26:A1.
    
    
76. Horton R. Persian Gulf syndrome puzzle. Lancet. 1994;343:1150-1.
    
    
77. Macilwain C. Call for more coordination of Gulf War syndrome research [News]. Nature. 1995;373:92.
    
    
78. DeFraites RF, Wanat ER, Norwood AE, Williams S, Cowan D, Callahan T. Investigation of a suspected outbreak of an unknown disease among veterans of Operation Desert Shield/Storm, 123d Army Reserve Command, Fort Benjamin Harrison, Indiana, April 1992. Washington, DC: Walter Reed Army Institute of Research; 1992.
    
    
79. Milner IB, Axelrod BN, Pasquantonio J, Sillanpaa M. Is there a Gulf war syndrome? [Letter]. JAMA. 1994;271:661.
    
    
80. Comprehensive Clinical Evaluation Program for Gulf War Veterans: Report on 18,598 Participants. Washington, DC: Office of the Assistant Secretary of Defense for Health Affairs-- Clinical Services; 1996.
    
    
81. Unexplained illness among Persian Gulf war veterans in an Air National Guard unit: preliminary report--August 1990-March 1995. MMWR Morb Mortal Wkly Rep. 1995;45:443-7.
    
    
82. Quin NE. The impact of diseases on military operations in the Persian Gulf. Mil Med. 1982;147:728-34.
    
    
83. Penman AD, Currier MM, Tarver RS. No evidence of increase in birth defects and health problems among children born to Persian Gulf War veterans in Mississippi. Mil Med. 1996;161:1-6.
    
    
84. Solomon Z, Waysman M, Levy G, Fried B, Mikulincer M, Benbenishty R, et al. From front line to home front: a study of secondary traumatization. Fam Process. 1992;31:289-302.
    
    
85. Beach P, Blanck RR, Gerrity T, Hyams KC, Mather S, Mazzuchi JF, et al. Coordinating federal efforts on Persian Gulf War veterans. Federal Practitioner. 1995;12:9-11, 15.
    
    
86. Roy MJ, Chung RC, Huntley DE, Blanck RR. Evaluating the symptoms of Persian Gulf war veterans. Federal Practitioner. 1994;11:13-16, 22.
    
    
87. Federal activities related to the health of Persian Gulf veterans. Washington, DC: Department of Veterans Affairs; 1995.
    
    
88. Beale P. Gulf illness [Letter]. BMJ. 1994;308:1574.
    
    
89. Revell T. The Gulf War syndrome [Letter]. BMJ. 1995;310:1073.
    
    
90. Labbate LA, Snow MP. Posttraumatic stress symptoms among soldiers exposed to combat in the Persian Gulf. Hosp Community Psychiatry. 1992;43:831-3.
    
    
91. Ross MC, Wonders J. An exploration of the characteristics of post-traumatic stress disorder in reserve forces deployed during Desert Storm. Arch Psychiatr Nurs. 1993;7:265-9.
    
    
92. Perconte ST, Wilson AT, Pontius EB, Dietrick AL, Spiro KJ. Psychological and war stress symptoms among deployed and non-deployed reservists following the Persian Gulf War. Mil Med. 1993;158:516-21.
    
    
93. Sutker PB, Uddo M, Brailey K, Allain AN. War-zone trauma and stress-related symptoms in Operation Desert Shield/Storm (ODS) returnees. Journal of Social Issues. 1993;49:33-49.
    
    
94. Southwick SM, Morgan A, Nagy LM, Bremner D, Nicolaou AL, Johnson DR, et al. Trauma-related symptoms in veterans of Operation Desert Storm: a preliminary report. Am J Psychiatry. 1993;150:1524-8.
    
    
95. Coate BD, Anderson CM, Gray GC, Hyams KC, and the Gulf War Veteran Research Team. Comparative study of hospitalizations among Gulf War veterans and era controls. In: Abstracts of the 123d Annual Meeting of the American Public Health Association and related organizations. San Diego, CA: American Public Health Association; 1995:2198.
    
    
96. Cowan D, DeFraites R, Wishik S, Gray G, Kuhn J, and the Gulf War Veterans Research Team. Birth defects and Persian Gulf War (PGW) service: a preliminary analysis. In: Abstracts of the 123d Annual Meeting of the American Public Health Association and related organizations. San Diego, CA: American Public Health Association; 1995:2198.
    
    
97. Kang HK, Bullman TA. Mortality follow-up study of Persian Gulf War veterans. In: Abstracts of the 123d Annual Meeting of the American Public Health Association and related organizations. San Diego, CA: American Public Health Association; 1995:2198.
    
    
98. The Persian Gulf experience and health. NIH Technology Assessment Workshop Panel. JAMA. 1994;272:391-5.
    
    
99. Health Consequences of Service during the Persian Gulf War: Initial Findings and Recommendations for Immediate Action. Washington, DC: National Academy Pr; 1995.
    
    
100. Evaluation of the U.S. Department of Defense Persian Gulf Comprehensive Clinical Evaluation Program. Washington, DC: National Academy Pr; 1995.
     
     
101. Presidential Advisory Committee on Gulf War Veterans' Illnesses. Interim Report. Washington, DC: U.S. Government Printing Office; 1996.
     
     
102. Vebrugge LM, Ascione FJ. Exploring the iceberg. Common symptoms and how people care for them. Med Care. 1987;25:539-69.
     
     
103. Kroenke K, Wood DR, Mangelsdorff AD, Meier NJ, Powell JB. Chronic fatigue in primary care: prevalence, patient characteristics, and outcome. JAMA. 1988;260:929-34.
     
     
104. Kroenke K, Arrington ME, Mangelsdorff AD. The prevalence of symptoms in medical outpatients and the adequacy of therapy. Arch Intern Med. 1990;150:1685-9.
     
     
105. Lloyd AR, Hickie I, Boughton CR, Spencer 0, Wakefield D. Prevalence of chronic fatigue syndrome in an Australian population. Med J Aust. 1990;153:522-8.
     
     
106. Stretch RH, Bliese PD, Marlowe DH, Wright KM, Knudson KH, Hoover CH. Physical health symptomatology of Gulf War-era service personnel from the states of Pennsylvania and Hawaii. Mil Med. 1995;160:131-6.
     
     
107. Ryan-Wenger NM. Physical and psychosocial impact of activation and deactivation on Army Reserve nurses. Mil Med. 1992;157:447-52.
     
     
108. Sutker PB, Uddo M, Brailey K, Allain AN, Errera P. Psychological symptoms and psychiatric diagnoses in Operation Desert Storm troops serving Graves registration duty. J Trauma Stress. 1994;7:159-71.
     
     
109. Hyams KC, Hanson K, Wignall FS, Escamilla J, Oldfield EC 3d. The impact of infectious diseases on the health of U.S. troops deployed to the Persian Gulf during Operations Desert Shield and Desert Storm. Clin Infect Dis. 1995;20:1497-504.
     
     
110. Wessely S, Chalder T, Hirsch S, Pawlikowska T, Wallace P, Wright DJ. Postinfectious fatigue: prospective cohort study in primary care. Lancet. 1995;345:1333-8.
     
     
111. Imboden JR. Canter A, Cluff LE, Trever RW. Brucellosis. III. Psychologic aspects of delayed convalescence. Arch Intern Med. 1959;103:406-14.
     
     
112. Imboden JR, Canter A, Cluff LE. Convalescence from influenza. A study of the psychological and clinical determinants. Arch Intern Med. 1961;108:393-9.
     
     
113. Eitrem R, Vene S, Niklasson B. Incidence of sand fly fever among Swedish United Nations soldiers on Cyprus during 1985. Am J Trop Med Hyg. 1990;43:207-11.
     
     
114. Straus, SE, Komaroff AL, Wedner HJ. Chronic fatigue syndrome: point and counterpoint. J Infect Dis. 1994;170:1-6.
     
     
115. Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff A. The chronic fatigue syndrome: a comprehensive approach to its definition and study. International Chronic Fatigue Syndrome Study Group. Ann Intern Med. 1994;121:953-9.
     
     
116. Goldberg J, Eisen SA, True WR, Henderson WG. Health effects of military service. Lessons learned from the Vietnam experience. Ann Epidemiol. 1992;2:841-53.
     
     
117. Haynes RB, Sackett DL, Taylor DW, Gibson ES, Johnson AL. Increased absenteeism from work after detection and labeling of hypertensive patients. N Engl J Med. 1978;299:741-4.
     
     
118. Cope H, David A, Pelosi A, Mann A. Predictors of chronic postviral fatigue. Lancet. 1994;344:864-8.
     
     
119. Barsky AJ, Borus JF. Somatization and medicalization in the era of managed care. JAMA. 1995;274:1931-4.
     
     
120. Roht LH, Vernon SW, Weir FW, Pier SM, Sullivan P, Reed LJ. Community exposure to hazardous waste disposal sites: assessing reporting bias. Am J Epidemiol. 1985;122:418-33.
     
     
121. Baker DR, Greenland S, Mendlein J, Harmon P. A health study of two communities near the Stringfellow Waste Disposal site. Arch Environ Health. 1988;43:325-34.
     
     
122. Decoufle P, Holmgreen P, Boyle CA, Stroup NE. Self-reported health status of Vietnam veterans in relation to perceived exposure to herbicides and combat. Am J Epidemiol. 1992;135:312-23.
     
     
123. Late M. TBE immunization limited in Bosnia. U.S. Medicine. 1996;32(Apr):1, 25.
     
     
124. Hammond EC. Some preliminary findings on physical complaints from a prospective study of 1,064,004 men and women. Am J Public Health. 1964;54:11-23.
     
     
125. Katon W, Ries RK, Kleinman A. The prevalence of somatization in primary care. Compr Psychiatry. 1984;25:208-15.
     
     
126. Kaplan C, Lipkin M Jr, Gordon GH. Somatization in primary care: patients with unexplained and vexing medical complaints. J Gen Intern Med. 1988;3:177-90.
     
     
127. Kroenke K, Spitzer RL, Williams JR, Linzer M, Hahn SR, deGruy FV 3d, et al. Physical symptoms in primary care. Predictors of psychiatric disorders and functional impairment. Arch Fam Med. 1994;3:774-9.
     
     
128. Frank JD. Emotional reactions of American soldiers to an unfamiliar disease. Am J Psychiatry. 1946;102:631-40.
     
     
129. Engel GL. The need for a new medical model: a challenge for biomedicine. Science. 1977;196:129-36.
     
     
130. Kleinman A, Eisenberg L, Good B. Culture, illness, and care: clinical lessons from anthropologic and cross-cultural research. Ann Intern Med. 1978;88:251-8.
     
     
131. Barsky AJ. The paradox of health. N Engl J Med. 1988;318:414-8.

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Table 1. Somatic Symptoms Commonly Associated with War-Related Medical and Psychological Illnesses*

Table 2. Comparison between Categories of War-Related Illnesses