American Journal of Epidemiology
Copyright © 1997 by The Johns Hopkins University School of Hygiene and Public Health
All rights reserved
Vol. 146, No. 9
Printed in U.S.A.
Invited Commentary: How Would We Know a Gulf War Syndrome
If We Saw One?
David H. Wegman,1 Nancy F. Woods, 2 and John C. Bailar3
Here we address a general issue raised by questions
about the "Persian Gulf syndrome" and toxic exposure
to troops engaged in the Persian Gulf War: where and
how does a new category of illness or disease become
established, and how can that process be improved?
Persian Gulf War veterans have reported health problems that many suggest are related to service in that
war during the period 1990-1991. A variety of complaints have been recorded by health care providers
throughout the country, but, for the most part, these
have not resulted in a clear diagnosis or explanation
except for a very small number of complaints which
have led to clear diagnoses such as leishmaniasis or
malaria. Several distinguished review panels have examined the evidence that service in the Gulf is related
to alleged chronic health problems (1-6). While these
reviews have caused participants to be impressed and
concerned about the veterans' complaints, no review
panel has arrived at a definitive understanding of the
veterans' illnesses. The review panels generally agree
that there is unlikely to be a single explanation for the
veterans' complaints. Consequently, health scientists
supported by both private and public funds have been
engaged in laboratory, clinical, and epidemiologic
studies to find the cause or causes of the illnesses.
Stress related to war, historically associated with
health problems (7), as well as particular features of
the Gulf War (major involvement of reserve troops,
first major conflict with a volunteer force, substantial
number of women soldiers) have been regularly cited
as important contributors to complaints and disability
among Gulf War veterans. An unknown number of
complaints are simply those unexplained symptoms
and illnesses experienced in any large population. (Almost 700,000 troops were present at some time during
Operation Desert Shield/Storm.)
The absence of clear explanations for most of the
illnesses has frustrated the veterans as well as health
scientists. The Department of Defense's very late release of information about potential exposure of some
of the troops to chemical or biologic weapons has
tended to confirm the belief that the real causes of the
illnesses are being covered up. Contributing to this
view are the absence of adequate medical records
about who received special immunizations that were
not in general use (anthrax and botulinum), and about
the use of pyridostigmine bromide pills to counter the
anticipated effects of nerve gases (1). In addition,
cutbacks in and limited use of field epidemiology staff
appear to have resulted in inadequate collection and
maintenance of objective information about the biologic or environmental risks experienced by service
personnel in the Gulf region. Given this serious lack of
information about risk factors, many believe that the
causes of illnesses for most of the veterans will never
be known.
CONFUSION WITH STRESS
Despite these problems, some investigators and clinicians treating affected veterans have continued to
seek explanations for those illnesses as well as effective means of treatment. The suggestion that stress
plays an important role has been largely rejected by
the veterans and some of their caregivers. Instead,
suggestions have been made that the illnesses are the
expression of one of several poorly understood syndromes, a result of exposure to agents with poorly
understood health effects, or explained by unconfirmed hypotheses regarding altered metabolism.
Some of the various explanations have included: syndromes such as chronic fatigue syndrome, fibromyalgia, and multiple chemical sensitivity, exposure to
agents such as depleted uranium, smoke from oil-well
fires, and dental amalgams, and hypotheses about al-
Received for publication July 23, 1997, and accepted for publication September 15, 1997.
Abbreviations: DSM, Diagnostic and Statistical Manual of Mental
Disorders; ICD, International Classification of Diseases.
1
Department of Work Environment, University of Massachusetts
Lowell, Lowell, MA.
2
Center for Women's Health Research, University of Washington, Seattle, WA.
3
Department of Health Studies, University of Chicago, Chicago,
IL.
Reprint requests to Dr. David H. Wegman, Department of Work
Environment, University of Massachusetts Lowell, Lowell, MA
01854.
704
Invited Commentary on Gulf War Syndrome
tered metabolism described as oxidative phosphorylation disorder, brainstem dysregulation syndrome, and
chemically induced porphyria (1).
It is unlikely that any of these hypotheses will
provide a unifying explanation for the problems. Most
will not stand the test of time. However, in this issue
of the Journal, Haley (8) calls attention to the inadequacies in studies that have been cited in support of
war-related stress as the major explanation of the
illnesses. While epidemiologists may argue with the
particular approach he takes to adjusting estimates of
prevalence of post-traumatic stress syndrome, Haley's
article calls attention to the fact that stress is at least as
difficult to study as some of the other hypotheses
suggested. He argues that investigators should not
attribute the veterans' problems to stress simply because the evidence needed to study physical factors is
not available.
The need for caution that Dr. Haley advises is well
taken when one is trying to identify causal factors. The
difficulty in studying stress, however, is no more reason to reject the role of stress in the veterans' illnesses
than it is a reason to reject physical causes. Landrigan
(9) summarized the reason to include stress in the
study and treatment of veterans:
As a nation, we need to get beyond the fallacious idea
that diseases of the mind either are not real or are
shameful, and to better recognize that the mind and
the body are inextricably linked (9, p. 261).
THE CORE ISSUE
The many efforts to understand illnesses in Gulf
War veterans call attention to a poorly recognized
problem faced by all investigators who study any
purported new condition or disease. Plaguing all such
investigations is the fact that there is no readily accepted process by which medical science determines
that a previously unrecognized disease should become
"recognized."
Several schemes have been proposed for evaluating
whether some specified exposure (broadly defined)
causes some specified illness (table 1). For example,
the 1964 report of the Surgeon General's advisory
committee on smoking and health (10) included a list
of criteria for causality. Hill (11) published a frequently cited list in 1965; both reports focused on
inferences of cause and effect from observational data.
Much earlier, Koch published "postulates" about
cause-effect inferences in the etiology of infectious
disease (12, pp. 22-23). Evans attempted to expand
Hill and Koch's criteria to all types of disease by
elaborating ten "Criteria for Causation" (13).
All of these efforts, however, address the relation
between some identified exposure and some recogAm J Epidemiol
Vol. 146, No. 9,1997
705
nized health outcome. The present task is different: it
is to determine whether there is another kind of outcome, either new or not previously recognized, that
should be added to our understanding about human
disease. If the answer to this last inquiry is "Yes," the
criteria of Koch, Hill, and/or Evans may then be appropriate in efforts to further understand this newly
described outcome.
In considering criteria that should inform decisions
about new diseases, it is important to consider the
different objectives that might be served by determining that a previously unrecognized condition should be
added to the disease lexicon. For physicians, the primary objective is the need to arrive at a consensus on
diagnostic criteria that will ultimately serve as the
basis for determining appropriate clinical approaches
to evaluation, treatment, or prevention of the condition
in persons who may be affected. In addition, clear
diagnostic criteria are needed to determine who suffers
from the condition and sometimes in what degree, so
that the natural history of the condition can be studied
successfully. These studies can identify relevant risk
factors and etiologic agents that cause the condition
and provide a basis for both treatment and prevention.
Some would call this a new nosologic entity. Proper
diagnosis and identification of the causal agent(s) for
each individual may also provide the basis (in the
United States) for determining who is to pay for the
care of the individual.
For the individual suffering from a candidate for a
new nosologic identification, correct identification of
the condition is important so that proper care or treatment for that condition can be sought. Other benefits
of proper identification include: avoidance of further
diagnostic tests that may be futile and expensive and
meeting the need many people have for "diagnostic
closure." In this regard, Eisenberg (14) has emphasized the important conceptual difference between
what he refers to as an illness and as a disease:
To state it flatly, patients suffer 'illnesses'; physicians
diagnose and treat 'diseases'. Let me make clear the
distinction I intend: illnesses are experiences of disvalued changes in states of being and in social function; diseases in the scientific paradigm of modern
medicine, are abnormalities in the structure and function of body organs and systems. . . . Illness and
disease, so defined, do not stand in a one-to-one
relationship. When disease is extreme. . . its pervasiveness makes illness inevitable. However, disease
may occur in the absence of illness. . . . [By contrast,]
similar degrees of organ pathology may generate quite
different reports of distress, differences determined by
culture, expectation and setting (14, p. 11).
Disease categories, therefore, should be understood
to be social constructions reflecting consensus not
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Wegman et al.
TABLE 1.
illness
Criteria of Koch, Evans, and Hill for evaluating whether some specified exposure (broadly defined) causes a specific
Koch: criteria of disease
causation (12)
Evans: postulates for the
causation of disease (13)
Hill: factors tor disease
association (11)
Parasite must be present in every
case of disease under appropriate
circumstances
The preventive factor must be consistently
present in persons of good health or
free of a particular disease
Strength of association
Parasite should occur in no other
disease as a fortuitous and nonpathogenic parasite
The factor must be isolatable in pure
form (i.e., can be identified as causal)
Consistency of association—repeatedly
observed by different persons, in
different places, circumstances, and
times
Parasite must be isolated from the
body in pure culture, repeatedly
passed, and induce new disease
The extent to which the factor is effectively
applied must parallel an increase in
good health and/or freedom from that
disease
Specificity of association
Experimental application of the factor
to one segment of a population
should significantly increase their
good health as compared with
matched controls
Temporality of association—exposure
occurs before disease
Withdrawal of the preventive factor
should be associated with an increase
of disease associated with that
factor
Biologic gradient or dose response
The effect of the factor shall be measured
in terms of lower morbidity and
mortality, longer life, and lower
medical costs
Plausibility of association
Coherence of association—cause and
effect interpretation should not seriously
conflict with the generally known
factors of the natural history and
biology of the disease
Experimental evidence
Analogous associations
only among health professionals but among the lay
public. People seeking explanations for their experiences of poor health achieve consensus among themselves that a set of symptoms and/or signs signifies
something different from other known categories common in their culture. This in turn often precipitates
their contact with health care professionals and other
healers to confirm or reject the normality or abnormality of the phenomenon.
Health professionals attempt to classify each condition recognized as a disease within a standard framework or taxonomy of professional construction such as
the International Classification of Diseases (ICD) (15)
or the Diagnostic and Statistical Manual of Mental
Disorders (DSM) (16). When the classification does
not seem to capture important aspects of the condition
(unusual symptoms, presence or absence of recognized causative agents, response to treatment, etc.),
clinicians commonly seek to explain what the condition represents and its possible etiology. This generally requires the development of a biologically plausible explanation for the condition compatible with a
more general understanding of normal versus abnormal. This process can lead to the proposal and acceptance of new disease categories that emerge ultimately
as the product of both lay (patient) and professional
constructions.
The setting of diagnostic criteria for a condition is
ultimately a social process, and as such is influenced
by multiple social forces. Among these are: 1) belief
systems prevalent in the culture/society about the phenomenon (i.e., the categories we have chosen to accept
Am J Epidemiol
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Invited Commentary on Gulf War Syndrome
as legitimate) (17, 18); 2) power relationships (who
has the power to declare a phenomenon a disease, or
abnormal condition) (19); 3) consequences of the diagnosis (insurance coverage, social ostracization); 4)
dominant frames of reference for explaining the diagnosis (e.g., see the changing explanations for chronic
fatigue syndrome (20)); and 5) who benefits from the
diagnosis (e.g., clinician does or does not get paid; patient does or does not have access to effective therapy).
When considered together, there are risks and benefits for patients, for physicians, and for society when
a new diagnostic category is invoked and acted on.
These were well summarized in the case of mitral
valve prolapse, when Quill et al. (21) examined the
border between normal variants in the population and
the developing interest in characterizing a variant as a
disease. Here the risks and benefits they described
have been supplemented by adding consideration of
not acting on a new diagnostic category (table 2).
Just as there are risks and benefits associated with
diagnosing a disease, there are also risks and benefits
of not making a diagnosis. For patients, not being
assigned a diagnosis may imply that their complaints
are not valid or serious, or forestall treatment while an
incorrect diagnosis may lead to treatment that is inappropriate or harmful. For clinicians, the risk of not
making a diagnosis include losing the respect of one's
patient (and potential loss of income), but benefits
include avoiding premature labeling and consequent
initiation of inappropriate therapy. Risks to the society
of no diagnosis may, for example, stigmatize individuals as malingering or feigning illness, or allow an
infectious condition to spread to others. Benefits of
making no diagnosis may include cost savings associated with no treatment and availability of a larger
segment of the population to contribute to the work of
society (because they are not excused by a diagnosis
from work or social roles). Being unable to diagnose a
problem may provide a beneficial impetus for study to
enlarge our understanding of what the problem is, and
development of accounts to predict and explain its
occurrence.
Diagnostic categories have evolved over the years,
resulting at intervals of roughly ten years in a revision
of formal codes for disease classification such as the
International Classification of Diseases (ICD) or the
Diagnostic and Statistical Manual of Mental Disorders (DSM). For the most part, changes in these codifications represent refinements that result from improved understanding of physio- or psychopathology.
Entirely new disease categories generally emerge
when there is recognition of a new clustering of symptoms in a population, usually with replication of their
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707
presentation across a series of patients. Once this happens, a provisional nomenclature is applied to the
phenomenon. Clinicians' confidence about differentiating the new phenomenon from other known phenomena increases most commonly when there are
technological developments or an objective marker
(e.g., an etiologic test or a biopsy finding) that has a
high probability of differentiating those with, from
those without, the condition. Although an objective
indicator is desirable, it may not be necessary and may
not even exist. Use of these indicators reflects clinicians' working models of causation or of pathologic
processes. Finally, as a consensus grows among professionals, formal diagnostic criteria emerge and modification in a taxonomy such as the ICD or DSM
ensues.
While the above describes the general progression
followed as a new disease category becomes accepted,
it does not indicate how this acceptance actually occurs.
In order to address the general concern that Persian
Gulf veterans have some new disease or diseases, we
need to develop a way to group events or symptoms
into one or several classes that will eventually allow
generalizations regarding the events and their various
causes. This requires that ill persons be grouped into
categories so that members of each category can be
distinguished from those of every other. The categories, in turn, need to be distinguished from already
existing categories.
The difficulty in accomplishing this goal is described by Susser (12):
The criteria of determinants and effects do not correspond with each other, first because determinants
have many effects and second because effects have
many determinants. . . . A single experience can give
rise to multiple and diverse manifestations; . . . . A
single manifestation, on the other hand, can arise as a
consequence of multiple and diverse experiences. . ..
(12, p. 45).
For example, there are many causes of inflammation,
while cigarette smoking has many health effects.
MacMahon and Pugh (22) provide some guidance
by noting that two different types of criteria, manifestational and causal, have been used to group ill persons:
1. Manifestational criteria: The ill persons are
grouped according to their similarity with respect
to symptoms, signs, changes in body fluids or
tissues, physiologic function, behavior, prognosis,
or some combination of these features. Examples
of diseases defined by manifestational criteria are
fracture of the femur, diabetes mellitus, mental
retardation, the common cold, schizophrenia, and
cervical cancer.
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Wegman et al.
TABLE 2.
Potential risks and benefits of attributing a diagnosis to a collection of symptoms and signs of disease*
Diagnosis
made
Patient
Yes
Risks
Benefits
Somatization
Explanation of puzzling symptoms
Unnecessary testing, treatment, and disability
Recognition of real preventable risk
Inaccurate attribution of symptoms
Sick role
Alienation from one's body
Feel reassured and normal
Increased physician attention
Physician
No
Complaints not considered valid
Forestalls inappropriate or harmful treatment
Yes
Inaccurate diagnosis
Easy explanation for complex symptoms
latrogenic harm
Feel and appear competent
Scientific error
Tight bonding with patient
Pressure to treat by "informed" patient
Intellectual challenge and income from tests and
visits
Reinforce unhealthy illness behavior
Recognition and minimization of real risk
Assists in determining next actions
No
Lose respect of patient
Avoid premature labeling and inappropriate therapy
Lose income from patient
Society
Yes
Medicalization
Detection of real risk and disease prevention
Disability
Make normal feel more normal
Unnecessary cost
Provides basis for epidemiologic investigation
Inappropriate stratification and assessment of
risk
No
Stigmatizing individuals as malingering or
feigning illness
Cost saving related to unneeded therapy
Failing to identify a communicable disease
Keeps individuals active members of society
Promotes further study to improve understanding
' Adapted from Quill et al. (21).
2. Causal criteria: Here the grouping depends on the
similarity of individuals with respect to a specified
experience believed to be a cause of their illness.
Examples of diseases defined by causal criteria are
birth trauma, silicosis, syphilis and lead poisoning
(22, p. 48).
MacMahon and Pugh describe several additional
important features related to the task of defining a
new disease. First they call attention to the fact that
"Polymorphous effects of newly isolated causal
agents may be understood, indeed expected" (22, p.
49). In this regard, they refer to the many different
illnesses associated with cigarette smoking.
Equally, they note that a causal agent may not be
associated with all those who are ill with the particular set of manifestations.
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Invited Commentary on Gulf War Syndrome
Finally they note that:
In the absence of knowledge of causal factors, manifestational criteria provide the only basis for. . . classification. Here the setting of the limits of disease
entities appears to be a highly intuitive process, having as a governing principle the assumption that the
greater the similarity of the manifestations of illness,
the more properly the illness of the persons exhibiting
the manifestations may be considered an entity (22, p.
51).
It is rare that a first effort at collecting a set of
manifestations will prove to be the final characterization of a disease. Increased attention to and study of
the condition may lead to more precise criteria for
diagnosis as well as some redefinition of the condition.
Indeed, it has been suggested that the patient described
by Alzheimer (23) did not have what we now call
Alzheimer's disease (16). Such diagnostic "drift" is
not rare. Moreover, the more heterogeneous the presentations and potential causes, the more difficult it
will be to define a new disease or syndrome. The
knowledge that accrues after the "disease" is first
defined, however, allows amendments that contribute
to better specification of the condition. Ultimately, the
"disease" may be grouped with others or separated
into more than one category as the newly defined
condition comes under systematic study.
For example, after evidence had been gathered on
the two separately defined disease categories spina
bifida and anencephaly, the natural history of the two
diseases in a variety of populations suggested they
could be reasonably considered as one entity now
known as "neural tube defect." Conversely, there was
a time when two patients, one with typhoid and one
with typhus infections but each presenting with a high
fever and rash, would have been diagnosed as having
the same disease. Isolation of causative agents and
better specification of the disease course led to recognition that these were two quite distinct diseases requiring separate diagnostic categories. In similar situations today, further study of an initial disease
definition generally leads to improved understanding
of the disease and its determinants, which in turn leads
to a change over time in the manifestations of the
disease that are considered as central to its definition
(24). Sometimes the definition of the disease may shift
entirely from being based on clinical history and physical examination to the related physiologic or laboratory observations, as has occurred with hypertension
and osteoporosis.
709
to initiate this process and evaluate the evidence that a
new disease, or a new category of diseases, should be
recognized. No single step is indispensable; they are
meant, rather, to guide analysis and to provide some
structure to deal with a problem that may be difficult
to resolve.
1. Differences from known conditions
The complex of signs, symptoms, and/or other findings must be sufficiently different from recognized
disease entities or syndromes to merit a new designation at some level of the diagnostic hierarchy. There
may be a conceptual problem in determining that some
condition is a separate entity versus a variant of something already recognized. There will always be boundary problems between illness and health. An answer of
"Yes" requires a complete and accurate description of
the new entity and of how it differs from entities
already recognized.
An example of a currently evolving syndrome that
may ultimately be accepted as a new disease is chronic
fatigue syndrome. While variants of this syndrome
have been traced back possibly as early as Hippocrates, the assignment of causal mechanisms over
the course of the 19th and 20th centuries seems to
reflect more the emerging understanding of more general disease processes than well-studied specific causal
links (20). In the 19th century, a focus on the nervous
system was associated with a condition called neurasthenia, while the mid-20th century's attention to infection characterized a similar condition as chronic
brucellosis. In the second half of this century, new
emphasis on endocrinology led to the suggestion that
hypoglycemia was the explanation for chronic fatigue.
Most recently, interest in immuno-toxicity has led to
syndromes labeled "total allergy syndrome" and
"chronic candidiasis." On careful examination, each of
these explanations has been dismissed, yet health practitioners continue to believe that there may be an
explainable syndrome that is characterized most prominently by chronic fatigue. As noted earlier, efforts to
understand and study chronic fatigue syndrome have
resulted in different sets of criteria being proposed for
defining the condition. Recently, investigators from
Australia, the United Kingdom, and the United States
have proposed a revision to an older definition explicitly for use in carefully designed studies of chronic
fatigue syndrome (25).
2. Appropriate limits of a definition
PROPOSED STEPS IN THE ANALYSIS
Recognizing that the process of defining a new
disease is necessarily iterative, we propose five criteria
Am J Epidemiol
Vol. 146, No. 9, 1997
The description, parameters, and severity of a new
condition must not be so broad as to exclude a common etiology, or so narrow as to suggest either bias
710
Wegman et al.
(and possibly mutual redefinition of symptoms) or
censoring (of possible atypical cases). For example,
for years, health scientists have noted a common late
afternoon wave of fatigue and have associated it with
circadian patterns of reduced blood sugar in that period of an individual's day. During the 1960s and
1970s, low blood sugar became an increasingly popular explanation for persistent fatigue. Along with the
emergence of the label hypoglycemia to explain protracted exhaustion, some caregivers began to argue for
the need to take an elaborate dietary history and to
introduce behavioral modification to correct the condition. Systematic population studies, however, have
demonstrated that the normal population includes numerous asymptomatic people with fasting or postprandial blood sugar levels in the range of 40 to 50 mg/dL
(24). Subsequent to these studies, the term hypoglycemia has gradually returned to more limited use as an
explanation of afternoon fatigue.
3. Replication by appropriate range of
practitioners
The condition must have been observed and confirmed by a significant number of qualified medical
practitioners, drawn from a broad panel of subdisciplines and places of practice. There would be some
suspicion, for example, if a new disease entity could
be recognized by surgeons, but not by internists, or by
doctors of osteopathy but not doctors of medicine, or
by physicians practicing in a specific locality, but not
by qualified peers brought in to evaluate the matter.
Enthusiasm for chronic brucellosis as an explanation for chronic fatigue syndrome accompanied Evans'
original publication (26). Failure to replicate the findings, and the demonstration that antibodies to brucella
were widespread and unrelated to fatigue in general
population studies, resulted in the ultimate rejection of
chronic brucellosis as a distinct condition characterized predominantly by chronic fatigue.
In contrast, reports that stomach ulcers could be
related to infection with Helicobacter pylori were initially met with disbelief by many mainstream physicians and research scientists (27, 28). Yet, widespread
replication of findings associating infection with stomach ulcers and gastritis has changed these attitudes,
and treatment of this infection now plays an important
role in therapy of stomach ulcers.
4. Common features and causes
The designation of a new disease category is not
entirely independent of considerations of cause and
effect, and adequate demonstration of a cause-effect
linkage can be persuasive that the effect should be
recognized. For example, do affected persons tend to
have something in common, e.g., common exposure^), common susceptibilities, or common demographic features? Does it seem that all categories of
persons with such features are susceptible? An answer
of "No" is not conclusive, because knowledge may be
incomplete, or because relevant exposure may be so
ubiquitous as to make the condition commonplace, but
we would expect such exceptions to be uncommon.
5. Context in which condition occurs
When evaluating the evidence that a new disease or
a new category of disease might deserve to be recognized, it is important to consider whether there are
undue pressures (including social, financial, and political) that promote or discourage the acceptance of a
new disease category. Such pressures may be generated, for example, by perceived governmental needs to
reduce medical coverage, by desire for income by
physicians or hospitals for services delivered, by patient-oriented concerns with compensation, by concerns about political vicissitudes, by incomplete or
biased news exposures, or by a sense of solidarity
among members of some possibly affected group. It
should be stressed that such pressures may not be
overt, they may be unrecognized by those they affect,
and they may at times even be recognized and seen as
laudable by persons who are dedicated to a cause.
These types of pressures must be prevented from serving as the primary determinant for whether a new
disease category should be established.
It is difficult to differentiate when pressure is legitimate (the medical community is properly reluctant to
recognize as "new" every condition that does not fit
readily into existing understanding of disease etiology)
from when pressure is undue (because it derives from
illegitimate or misguided interests of affected parties).
When there is disagreement between lay and professional groups and/or among professionals, the search
for explanatory models propels both groups to act. The
lay group considers alternative attributions for the
cause of the disease, as well as for the cause of
the professionals' disagreement or failure to name the
experience. Development of criteria for human immunodeficiency virus-acquired immunodeficiency syndrome (HIV-AIDS) exemplifies the processes in
which lay people organized to prod the professionals
to improve their understanding of a new phenomenon
in which there had been little previous interest or
attention. Past breeches of trust between patients and
professionals (e.g., over the effects of the use of diethylstilbestrol (DES) and the Dalkon shield, and in
regard to the effects of black lung and byssinosis) have
created a sociopolitical context against which the pubAm J Epidemiol
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Invited Commentary on Gulf War Syndrome
lie makes inferences about patient/professional disagreements.
The five criteria proposed for use when exploring
the possibility that a new condition exists are neither
exhaustive nor fail-safe. They are proposed in an effort
to promote a more systematic approach to the consideration of suggestions that a new condition such as a
Gulf War syndrome exists. Determination that a new
disease exists is potentially important with respect to
differential diagnosis, treatment decisions, and properly targeted prevention efforts, as well as the design
of research programs. The emergence of any new
disease process presents a serious and difficult challenge to medical science. Understandably, physicians
are comforted by the known, and troubled by conditions that they cannot readily explain. All of us need
help in finding ways to see our environment in a new
light, and to learn how that new light changes what we
can subsequently observe.
In the end, we are doubtful that the symptoms linked
with Persian Gulf syndrome can meet these or other
reasonable criteria for the diagnosis of a new condition. However, it is possible that new research findings
will shift the totality of evidence in the other direction.
Much research on Gulf War syndrome is already in
progress, and more will surely be undertaken as both
our understanding of the matter and the needed research tools develop.
ACKNOWLEDGMENTS
A portion of this commentary was prepared during the
authors' work while serving on the Institute of Medicine's
Committee to Review the Health Consequences of Service
During the Persian Gulf War (2). Helpful comments were
received from several other members of the committee, as
well as from Dr. Myron E. Wegman.
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