Cognitive decrements in 1991 Gulf War veterans: associations with Gulf War illness and neurotoxicant exposures in the Boston Biorepository, Recruitment, and Integrative Network (BBRAIN) cohorts

BACKGROUND

During deployment, veterans of the 1991 Gulf War (GW) were exposed to multiple war-related toxicants. Roughly a third of these veterans continue to exhibit neurotoxicant induced symptoms of Gulf War Illness (GWI), a multi-faceted condition that includes fatigue, pain and cognitive decrements. When studied empirically, both deployed veterans with exposures and those who meet the criteria for GWI are more likely to show deficits in the area of neuropsychological functioning. Although studies have shown cognitive impairments in small sample sizes, it is necessary to revisit these findings with larger samples and newer cohorts to see if other areas of deficit emerge with more power to detect such differences. A group of researchers and clinicians with expertise in the area of GWI have identified common data elements (CDE) for use in research samples to compare data sets. At the same time, a subgroup of researchers created a new repository to share these cognitive data and biospecimens within the GWI research community.

METHODS

The present study aimed to compare cognitive measures of attention, executive functioning, and verbal memory in a large sample of GWI cases and healthy GW veteran controls using neuropsychological tests recommended in the CDEs. We additionally subdivided samples based on the specific neurotoxicant exposures related to cognitive deficits and compared exposed versus non-exposed veterans regardless of case criteria status. The total sample utilized cognitive testing outcomes from the newly collated Boston, Biorepository, Recruitment, and Integrative Network (BBRAIN) for GWI.

RESULTS

Participants included 411 GW veterans, 312 GWI (cases) and 99 healthy veterans (controls). Veterans with GWI showed significantly poorer attention, executive functioning, learning, and short-and-long term verbal memory than those without GWI. Further, GW veterans with exposures to acetylcholinesterase inhibiting pesticides and nerve gas agents, had worse performance on executive function tasks. Veterans with exposure to oil well fires had worse performance on verbal memory and those with pyridostigmine bromide anti-nerve gas pill exposures had better verbal memory and worse performance on an attention task compared to unexposed veterans.

CONCLUSIONS

This study replicates prior results regarding the utility of the currently recommended CDEs in determining impairments in cognitive functioning in veterans with GWI in a new widely-available repository cohort and provides further evidence of cognitive decrements in GW veterans related to war-related neurotoxicant exposures.

The Gulf War Illness and the Iraqi Population's Forgotten Pain and Suffering

Exposure to chemical warfare agents results in long-term biopsychosocial complaints. A recent study has revealed an association between exposure to a low dose of Sarin and Gulf War illness in American veterans from the Gulf War. The prevalence of Gulf War illness has not been studied in the Iraqi population. In light of recent research results, Iraqi chemical warfare agent survivors' multiple physical and mental illnesses should be highlighted. For this reason, establishing both legislation and medical commissions is most needed.

Brain-Specific Increase in Leukotriene Signaling Accompanies Chronic Neuroinflammation and Cognitive Impairment in a Model of Gulf War Illness

Persistent cognitive impairment is a primary central nervous system-related symptom in veterans afflicted with chronic Gulf War Illness (GWI). Previous studies in a rat model have revealed that cognitive dysfunction in chronic GWI is associated with neuroinflammation, typified by astrocyte hypertrophy, activated microglia, and enhanced proinflammatory cytokine levels. Studies in a mouse model of GWI have also shown upregulation of several phospholipids that serve as reservoirs of arachidonic acid, a precursor of leukotrienes (LTs). However, it is unknown whether altered LT signaling is a component of chronic neuroinflammatory conditions in GWI. Therefore, this study investigated changes in LT signaling in the brain of rats displaying significant cognitive impairments six months after exposure to GWI-related chemicals and moderate stress. The concentration of cysteinyl LTs (CysLTs), LTB4, and 5-Lipoxygenase (5-LOX), the synthesizing enzyme of LTs, were evaluated. CysLT and LTB4 concentrations were elevated in the hippocampus and the cerebral cortex, along with enhanced 5-LOX expression in neurons and microglia. Such changes were also associated with increased proinflammatory cytokine levels in the hippocampus and the cerebral cortex. Enhanced CysLT and LTB4 levels in the brain could also be gleaned from their concentrations in brain-derived extracellular vesicles in the circulating blood. The circulating blood in GWI rats displayed elevated proinflammatory cytokines with no alterations in CysLT and LTB4 concentrations. The results provide new evidence that a brain-specific increase in LT signaling is another adverse alteration that potentially contributes to the maintenance of chronic neuroinflammation in GWI. Therefore, drugs capable of modulating LT signaling may reduce neuroinflammation and improve cognitive function in GWI. Additional findings demonstrate that altered LT levels in the brain could be tracked efficiently by analyzing brain-derived EVs in the circulating blood.

Molecular mechanisms for the antidepressant-like effects of a low-dose ketamine treatment in a DFP-based rat model for Gulf War Illness

Exposure to organophosphates (OP) during the First Gulf War is among one of the factors for Gulf War Illness (GWI) development in veterans and it has been challenging to treat GWI symptoms with existing therapies. Ketamine produces a rapid-onset and sustained antidepressant response, but there is no evidence whether ketamine treatment is effective for GWI depression. Repeated, low-dose exposure to diisopropyl fluorophosphate (DFP) mimic Gulf War related OP exposures and produces a chronic depressive state in rats. In this study, DFP-exposed rats treated with ketamine (10 mg/kg, i.p.) exhibited antidepressant-like effect on the Forced Swim Test at 1-h. This effect persisted at 24-h post ketamine, a time-point by which it is eliminated from the brain suggesting involvement of mechanisms that affect long-term synaptic plasticity. Western blot analysis showed significantly lower Brain-Derived Neurotrophic Factor (BDNF) levels in DFP rat brains. Ketamine produced a nonsignificant increase in BDNF expression at 1-h but produced a larger, significant (2.2-fold) increase at 24-h in DFP rats. We previously reported chronic hippocampal calcium elevations ([Ca2+]i) in DFP rats. Ketamine-treated DFP rats exhibited significantly lower [Ca2+]i at 1-h but not at 24-h. Interestingly, treatment with ANA-12, a TrkB-BDNF receptor antagonist, in DFP rats blunted ketamine's antidepressant-like effect at 24-h but not at 1-h. These experiments suggest that in a rat model of DFP-induced depression, inhibition of the NMDAR-Ca2+ contributes to the rapid-onset antidepressant effects of ketamine while the antidepressant actions that persisted at 24-h post ketamine administration involve upregulation of BDNF signaling.

Targeting sirtuin activity with nicotinamide riboside reduces neuroinflammation in a GWI mouse model

Gulf War Illness (GWI) affects 30% of veterans from the 1991 Gulf War (GW), who suffer from symptoms that reflect ongoing mitochondria dysfunction. Brain mitochondria bioenergetics dysfunction in GWI animal models corresponds with astroglia activation and neuroinflammation. In a pilot study of GW veterans (n = 43), we observed that blood nicotinamide adenine dinucleotide (NAD) and sirtuin 1 (Sirt1) protein levels were decreased in the blood of veterans with GWI compared to healthy GW veterans. Since nicotinamide riboside (NR)-mediated targeting of Sirt1 is shown to improve mitochondria function, we tested whether NR can restore brain bioenergetics and reduce neuroinflammation in a GWI mouse model. We administered a mouse diet supplemented with NR at 100μg/kg daily for 2-months to GWI and control mice (n = 27). During treatment, mice were assessed for fatigue-type behavior using the Forced Swim Test (FST), followed by euthanasia for biochemistry and immunohistochemistry analyses. Fatigue-type behavior was elevated in GWI mice compared to control mice and lower in GWI mice treated with NR compared to untreated GWI mice. Levels of plasma NAD and brain Sirt1 were low in untreated GWI mice, while GWI mice treated with NR had higher levels, similar to those of control mice. Deacetylation of the nuclear-factor κB (NFκB) p65 subunit and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) was an increase in the brains of NR-treated GWI mice. This corresponded with a decrease in pro-inflammatory cytokines and lipid peroxidation and an increase in markers of mitochondrial bioenergetics in the brains of GWI mice. These findings suggest that targeting NR mediated Sirt1 activation restores brain bioenergetics and reduces inflammation in GWI mice. Further evaluation of NR in GWI is warranted to determine its potential efficacy in treating GWI.

Gulf war illness-related chemicals increase CD11b/c+ monocyte infiltration into the liver and aggravate hepatic cholestasis in a rodent model

Gulf War Illness (GWI) is a chronic multisymptom disorder affecting veterans of the 1990-91 Gulf war. GWI was linked with exposure to chemicals including the nerve gas prophylactic drug pyridostigmine-bromide (PB) and pesticides (DEET, permethrin). Veterans with GWI exhibit prolonged, low-level systemic inflammation, though whether this impacts the liver is unknown. While no evidence exists that GWI-related chemicals are hepatotoxic, the prolonged inflammation may alter the liver's response to insults such as cholestatic injury. We assessed the effects of GWI-related chemicals on macrophage infiltration and its subsequent influence on hepatic cholestasis. Sprague Dawley rats were treated daily with PB, DEET and permethrin followed by 15 minutes of restraint stress for 28 days. Ten weeks afterward, GWI rats or naïve age-matched controls underwent bile duct ligation (BDL) or sham surgeries. Exposure to GWI-related chemicals alone increased IL-6, and CD11b+F4/80- macrophages in the liver, with no effect on biliary mass or hepatic fibrosis. However, pre-exposure to GWI-related chemicals enhanced biliary hyperplasia and fibrogenesis caused by BDL, compared to naïve rats undergoing the same surgery. These data suggest that GWI patients could be predisposed to developing worse liver pathology due to sustained low-level inflammation of the liver when compared to patients without GWI.

Neuropsychological characteristics of Gulf War illness: A meta-analysis

OBJECTIVE

Gulf War illness (GWI) is a disorder related to military service in the 1991 GW. Prominent symptoms include fatigue, pain and cognitive problems. These symptoms were reported by GW Veterans (GWV) immediately after the war and were eventually incorporated into case definitions of GWI. Neuropsychological function in GW veterans has been studied both among deployed GWV and in GWV diagnosed with GWI. Results have been inconsistent between and across GW populations. The purpose of the present investigation was to better characterize neuropsychological function in this veteran population.

METHODS

Meta-analysis techniques were applied to published studies on neuropsychological performance in GWV to identify domains of dysfunction in deployed vs. non-deployed GW-era veterans and symptomatic vs. non-symptomatic GWVs.

RESULTS

Significantly decreased performance was found in three functional domains: attention and executive function, visuospatial skills and learning/memory.

CONCLUSIONS

These findings document the cognitive decrements associated with GW service, validate current GWI case definitions using cognitive criteria, and identify test measures for use in GWI research assessing GWI treatment trial efficacy.

Insomnia Severity, Subjective Sleep Quality, and Risk for Obstructive Sleep Apnea in Veterans With Gulf War Illness

Despite the fact that sleep disturbances are common in veterans with Gulf War Illness (GWI), there has been a paucity of published sleep studies in this veteran population to date. Therefore, the present study examined subjective sleep quality (assessed with the Pittsburgh Sleep Quality Index), insomnia severity (assessed with the Insomnia Severity Index), and risk for obstructive sleep apnea (assessed with the STOP questionnaire) in 98 Gulf War veterans. Veterans with GWI, defined either by the Kansas or Centers for Disease Control and Prevention criteria, had greater risk for obstructive sleep apnea (i.e., higher STOP scores) than veterans without GWI. This difference persisted even after accounting for potentially confounding demographic (e.g., age, gender) and clinical variables. Veterans with GWI, defined by either the Kansas or Centers for Disease Control and Prevention criteria, also had significantly greater insomnia severity and poorer sleep quality than veterans without GWI (p < 0.05), even after accounting for potentially confounding variables. Furthermore, there were significant, positive correlations between insomnia severity, subjective sleep quality, and GWI symptom severity (p ≤ 0.01). In stepwise linear regression models, insomnia severity significantly predicted GWI status over and above demographic and clinical variables. Together these findings provide good rationale for treating sleep disturbances in the management of GWI.

Memory and functional brain differences in a national sample of U.S. veterans with Gulf War Illness

Roughly 26-32% of U. S. veterans who served in the 1991 Persian Gulf War report suffering from chronic health problems. Memory complaints are regularly reported by ill Gulf War veterans (GWV), but limited data verify their complaints. This study investigated episodic memory and brain function in a nationally representative sample of GWV, using a face-name memory task and functional magnetic resonance imaging during encoding. A syndrome classification system was used to subdivide ill GWV into the three major Gulf War Illness syndrome types, "impaired cognition" (GWV-1), "confusion ataxia" (GWV-2), and "central pain" (GWV-3). Memory and brain function of ill GWV were contrasted to deployed and nondeployed well GWV controls (GWV-C). Ill GWV exhibited impaired memory function relative to GWV-C but the patterns of functional brain differences varied. Brain activation differentiated the GWV-C from the ill GWV. The different syndrome types also differed from one another in several brain regions. Additionally, the current study was the first to observe differences in brain function between deployed and nondeployed GWV-C. These results provide (1) evidence of memory impairment in ill GWV and differentiate the syndrome types at a functional neurobiological level, and (2) the role of deployment in the war on brain function.

Achieving Remission in Gulf War Illness: A Simulation-Based Approach to Treatment Design

Gulf War Illness (GWI) is a chronic multi-symptom disorder affecting up to one-third of the 700,000 returning veterans of the 1991 Persian Gulf War and for which there is no known cure. GWI symptoms span several of the body’s principal regulatory systems and include debilitating fatigue, severe musculoskeletal pain, cognitive and neurological problems. Using computational models, our group reported previously that GWI might be perpetuated at least in part by natural homeostatic regulation of the neuroendocrine-immune network. In this work, we attempt to harness these regulatory dynamics to identify treatment courses that might produce lasting remission. Towards this we apply a combinatorial optimization scheme to the Monte Carlo simulation of a discrete ternary logic model that represents combined hypothalamic-pituitary-adrenal (HPA), gonadal (HPG), and immune system regulation in males. In this work we found that no single intervention target allowed a robust return to normal homeostatic control. All combined interventions leading to a predicted remission involved an initial inhibition of Th1 inflammatory cytokines (Th1Cyt) followed by a subsequent inhibition of glucocorticoid receptor function (GR). These first two intervention events alone ended in stable and lasting return to the normal regulatory control in 40% of the simulated cases. Applying a second cycle of this combined treatment improved this predicted remission rate to 2 out of 3 simulated subjects (63%). These results suggest that in a complex illness such as GWI, a multi-tiered intervention strategy that formally accounts for regulatory dynamics may be required to reset neuroendocrine-immune homeostasis and support extended remission.

Exercise challenge in Gulf War Illness reveals two subgroups with altered brain structure and function

Nearly 30% of the approximately 700,000 military personnel who served in Operation Desert Storm (1990-1991) have developed Gulf War Illness, a condition that presents with symptoms such as cognitive impairment, autonomic dysfunction, debilitating fatigue and chronic widespread pain that implicate the central nervous system. A hallmark complaint of subjects with Gulf War Illness is post-exertional malaise; defined as an exacerbation of symptoms following physical and/or mental effort. To study the causal relationship between exercise, the brain, and changes in symptoms, 28 Gulf War veterans and 10 controls completed an fMRI scan before and after two exercise stress tests to investigate serial changes in pain, autonomic function, and working memory. Exercise induced two clinical Gulf War Illness subgroups. One subgroup presented with orthostatic tachycardia (n = 10). This phenotype correlated with brainstem atrophy, baseline working memory compensation in the cerebellar vermis, and subsequent loss of compensation after exercise. The other subgroup developed exercise induced hyperalgesia (n = 18) that was associated with cortical atrophy and baseline working memory compensation in the basal ganglia. Alterations in cognition, brain structure, and symptoms were absent in controls. Our novel findings may provide an understanding of the relationship between the brain and post-exertional malaise in Gulf War Illness.

Impaired response inhibition in ill Gulf War veterans

Poor performance on tasks requiring response inhibition has been observed among chronically ill veterans of the 1991 Persian Gulf War. Semantic difficulties have also been reported. We collected event-related potential (ERP) and behavioral data from 25 Gulf War veterans who complained of cognitive difficulties and from 23 matched controls, who were deployed but not symptomatic, while they performed a GO-NOGO task that required both a semantic decision and inhibitory processing. A significantly greater false-alarm rate among the ill veterans was accompanied in the ERP data by significantly reduced amplitude in the NOGO P3, consistent with previous ERP studies of other patient groups that have shown poor inhibitory response performance. This supports the contention that the ill veterans' deficit lies more in inhibiting than in detecting task-related differences in the stimuli.

Physical, psychological, and functional comorbidities of multisymptom illness in Australian male veterans of the 1991 Gulf War

Multisymptom illness is more prevalent in 1991 Gulf War veterans than in military comparison groups; less is known about comorbidities. The authors compared physical, psychological, and functional comorbidities in Australian male Gulf War I veterans with those in actively (non-Gulf) deployed and nondeployed military personnel by using a questionnaire and medical assessment in 2000-2002. Multisymptom illness was more common in male Gulf War veterans than in the comparison group (odds ratio (OR) = 1.80, 95% confidence interval (CI): 1.48, 2.19). Stratifying by deployment status in the comparison group made little difference in this association. Gulf War veterans with multisymptom illness had increased psychiatric disorders, including major depression (OR = 6.31, 95% CI: 4.19, 9.52) and posttraumatic stress disorder (OR = 9.77, 95% CI: 5.39, 18.59); increased unexplained chronic fatigue (OR = 13.32, 95% CI: 7.70, 23.05); and more reported functional impairment and poorer quality of life, but objective physical and laboratory outcomes were similar to those for veterans without multisymptom illness. Similar patterns were found in the comparison groups; differences across the 3 groups were statistically significant for only hospitalization, obstructive liver disease, and Epstein-Barr virus exposure. Multisymptom illness is more prevalent in Gulf War I veterans, but the pattern of comorbidities is similar for actively deployed and nondeployed military personnel.

Aluminum adjuvant linked to Gulf War illness induces motor neuron death in mice

Gulf War illness (GWI) affects a significant percentage of veterans of the 1991 conflict, but its origin remains unknown. Associated with some cases of GWI are increased incidences of amyotrophic lateral sclerosis and other neurological disorders. Whereas many environmental factors have been linked to GWI, the role of the anthrax vaccine has come under increasing scrutiny. Among the vaccine's potentially toxic components are the adjuvants aluminum hydroxide and squalene. To examine whether these compounds might contribute to neuronal deficits associated with GWI, an animal model for examining the potential neurological impact of aluminum hydroxide, squalene, or aluminum hydroxide combined with squalene was developed. Young, male colony CD-1 mice were injected with the adjuvants at doses equivalent to those given to US military service personnel. All mice were subjected to a battery of motor and cognitive-behavioral tests over a 6-mo period postinjections. Following sacrifice, central nervous system tissues were examined using immunohistochemistry for evidence of inflammation and cell death. Behavioral testing showed motor deficits in the aluminum treatment group that expressed as a progressive decrease in strength measured by the wire-mesh hang test (final deficit at 24 wk; about 50%). Significant cognitive deficits in water-maze learning were observed in the combined aluminum and squalene group (4.3 errors per trial) compared with the controls (0.2 errors per trial) after 20 wk. Apoptotic neurons were identified in aluminum-injected animals that showed significantly increased activated caspase-3 labeling in lumbar spinal cord (255%) and primary motor cortex (192%) compared with the controls. Aluminum-treated groups also showed significant motor neuron loss (35%) and increased numbers of astrocytes (350%) in the lumbar spinal cord. The findings suggest a possible role for the aluminum adjuvant in some neurological features associated with GWI and possibly an additional role for the combination of adjuvants.

Chronic fatigue syndrome and related disorders in UK veterans of the Gulf War 1990-1991: results from a two-phase cohort study

BACKGROUND

The aim was to determine the prevalence of chronic fatigue syndrome (CFS), chronic fatigue and fibromyalgia in UK military personnel after the Gulf War 1990-1991.

METHOD

A two-phase cohort study was used. Three randomly selected subsamples identified from a population-based cross-sectional postal survey of over 10,000 current and ex-service UK military personnel (Gulf veterans were those deployed to the Gulf War 1990-1991; non-Gulf veterans were Bosnia peacekeepers 1992-1997 and those on active duty during the Gulf War 1990-1991 but not deployed) were recruited. Their disability status was assessed using the Short Form 36 physical functioning scale; Gulf veterans who reported physical disability (n=111) were compared with non-Gulf (n=133) veterans who reported similar levels of physical disability. Screening for known medical and psychiatric conditions was conducted to exclude medical explanations for disability and symptomatic distress. Standardised criteria for CFS, chronic fatigue and fibromyalgia were used.

RESULTS

Disabled Gulf veterans were more likely to be overweight, have elevated gamma-glutamyl transferase levels and screen positive for hypertension. There were no other clinically significant differences in clinical markers for medically explainable conditions. Disabled Gulf veterans were more likely than similarly disabled Bosnia and Era veterans (adjusted odds ratio 7.8, 95% confidence interval 2.5-24.5) to meet the criteria for CFS. Rates for other medically unexplained conditions were not significantly increased.

CONCLUSIONS

Symptoms in keeping with CFS account for a significant part of the symptomatic distress in Gulf veterans.

Gulf war syndrome: a reaction to psychiatry's invasion of the military?

Following the 1991 Gulf War, a number of soldiers who fought there began to complain of various symptoms and disorders, the collection of which came to be known as Gulf War syndrome (GWS). A debate has raged about the nature and cause of this illness, with many suggesting that it is a psychiatric condition. GWS continues to be a contested illness, yet there is no disputing that many Gulf veterans are ill. This article considers the way in which GWS sufferers understand their illness to be physical in nature and the way in which they negotiate and resist psychological theories of their illness. Based on 14 months of ethnographic fieldwork in the United Kingdom, data for this article were collected mainly by in-depth, semistructured interviews with GWS sufferers, their family members, doctors, and scientists, as well as healthy Gulf veterans. A total of 93 informants were interviewed, including 67 UK Gulf veterans, most of whom were ill. The paper argues that despite the increasing presence of psychiatry in military discourse, GWS reveals the way that people are able to transform, negotiate and even negate its power and assumptions.

Delayed behavioral and endocrine effects of sarin and stress exposure in mice

The organophosphorus agent sarin is a potent inhibitor of acetylcholinesterase. Experiments tested the influence of exposure to low doses of sarin along with psychological stress on delayed behavioral and endocrine changes in mice. Motor activity, acoustic startle response (ASR), pre-pulse inhibition (PPI) of ASR, activity of cholinesterase in blood and catecholamine levels in adrenals were evaluated after low dose sarin exposure (3 x 0.4 LD50 subcutaneously) combined with chronic intermittent stress in C57BL/6J mice. While sarin alone produced depression of motor activity, no interaction of the stress with sarin exposure was observed. Cholinesterase activity was significantly reduced 24 h after exposure to sarin; however, the basal activity was re-established 3 weeks later. The combination of low dose sarin exposure and stress produced delayed behavioral change manifested as excessive grooming together with endocrine alterations in adrenals 7 weeks after exposure. The size of the adrenals in the combined exposure group was increased and the concentration of catecholamines was significantly decreased. In conclusion, these findings indicate that sarin in low doses is more dangerous when combined with shaker stress inducing delayed behavioral and endocrine changes.

Gulf War Illness: lessons from medically unexplained symptoms

Service in the Persian Gulf in 1991 is associated with increased reporting of symptoms and distress in a proportion of those who served there. Yet despite clear evidence of an increase in symptom burden and a decrease in well being, exhaustive clinical and laboratory based scientific research has failed to document many reproducible biomedical abnormalities in this group. Likewise, there has been no evidence of an increase in disease related mortality. Formal psychiatric disorders are twice as common in Gulf War veterans, as might be expected in the aftermath of any conflict, but this too is insufficient to explain the ill-health observed. Many service personnel who returned unwell believe that they have Gulf War Syndrome, and that their ill-health is due to exposures that they encountered in theatre. Research on multiple exposures to date has not generated a plausible aetiological mechanism for veterans' ill-health. Even if medical research has failed to provide a satisfactory explanation, it remains the case that many of those affected continue to be unwell and disabled some 15 years after returning from combat. For this reason, it is time that more attention is given to developing effective interventions to relieve their ill-health and distress. In this review we discuss the importance of the wider social context, individual illness beliefs and attributions and go on to outline a model of continuing ill-health in Gulf veterans. The review concludes with some suggestions for future research priorities, in particular the need for further qualitative studies to further our understanding of the illness, in order that better treatments may be developed.

Army research needs for automated neuropsychological tests: Monitoring soldier health and performance status☆

Information on the mental status of soldiers operating at the limits of human tolerance will be vital to their management in future deployments; it may also allow earlier intervention for conditions such as undiagnosed Gulf War illnesses and Parkinson's Disease. The Army needs a parsimonious set of neuropsychological tests that reliably identify subtle changes for: (1) early detection of individual health and military performance impairments and (2) management of occupational and deployment health risks. Testing must characterize cognitive lapses in healthy individuals faced with relevant operational stressors (i.e., anxiety, information overload, thermal strain, hypoxia, fatigue, head impact, chemical or radiation exposures, metabolic challenges). This effort must also explore the neuropsychological methods in militarily relevant conditions to extend our understanding of relevant functional domains and how well they correspond to modes of testing. The ultimate objective is unobtrusive real-time mental status monitoring.

Pain in veterans of the Gulf War of 1991: a systematic review

Background

Veterans of the Persian Gulf War of 1991 have reported a range of adverse health symptoms. This systematic review aims to identify all studies that have compared the prevalence of symptoms of pain in veterans of the Gulf War to that in a non-Gulf military comparison group, and to determine whether Gulf War veterans are at increased risk of reporting pain.

Methods

Studies published between January 1990 and May 2004 were identified by searching a large number of electronic databases. Reference lists and websites were also searched and key researchers were contacted. Studies were included if they reported the prevalence of any symptom or condition that included the word "pain" in Gulf War veterans and in a comparison group of non-Gulf veterans. 2401 abstracts were independently reviewed by two authors.

Results

Twenty studies fulfilled the inclusion criteria. Five main sites of pain were identified (muscle, joint, chest/heart, back and abdominal pain) and separate meta-analyses were performed to summarise the results related to each site. A greater proportion of Gulf veterans reported symptoms at each site of pain when compared to a non-Gulf military group. Gulf deployment was most strongly associated with abdominal pain, with Gulf veterans being more than three times more likely to report such pain than a comparison group (OR 3.23; 95%CI 2.31–4.51). Statistical heterogeneity between study estimates was significant, probably due to variation in measured periods of prevalence and symptom measurement methods.

Conclusion

A higher proportion of veterans of the Persian Gulf War of 1991 reported symptoms of pain than military comparison groups. This is consistent with previously demonstrated increased reporting of more general symptoms (fatigue, multiple chemical sensitivity, post traumatic stress disorder) in these veterans compared with non-Gulf military groups. However, the primary studies were heterogeneous and varied greatly in quality.

Predictors of Exercise Compliance in Individuals with Gulf War Veterans Illnesses: Department of Veterans Affairs Cooperative Study 470

Although the health benefits of exercise for individuals with Persian Gulf War veterans illnesses (GWVI) are documented, many of these individuals do not exercise regularly enough to obtain benefits. The purpose of this study was to investigate factors predicting exercise compliance among individuals with GWVI in a multicenter, randomized, clinical trial. Participants were 1,092 veterans who reported at least two of the following cardinal symptoms of GWVI: (1) fatigue, (2) musculoskeletal pain, and (3) cognitive problems. Participants received exercise alone or exercise and cognitive-behavioral therapy. The overall level of compliance was relatively low during the exercise treatment phase (46.2%) and decreased by one-half during the follow-up period (23.0%). Predictors of compliance during treatment included less pain and greater age, motivation, and body mass index. Predictors of compliance during the follow-up period included less pain and greater age. The results highlight factors that affect adoption and maintenance of physical activity in a population with GWVI.

Risk and the social construction of 'Gulf War Syndrome'

Fifteen years since the events that are held by some to have caused it, Gulf War Syndrome continues to exercise the mind and energies of numerous researchers across the world, as well as those who purport to be its victims and their advocates in the media, law and politics. But it may be that the search for a scientific or medical solution to this issue was misguided in the first place, for Gulf War Syndrome, if there is such an entity, appears to have much in common with other 'illnesses of modernity', whose roots are more socially and culturally driven than what doctors would conventionally consider to be diseases. The reasons for this are complex, but derive from our contemporary proclivity to understand humanity as being frail and vulnerable in an age marked by an exaggerated perception of risk and a growing use of the 'politics of fear'. It is the breakdown of social solidarities across the twentieth century that has facilitated this process.Unfortunately, as this paper explores, our inability to understand the social origins of self-hood and illness, combined with a growing cynicism towards all sources of authority, whether political, scientific, medical or corporate, has produced a powerful demand for blame and retribution deriving from a resolute few who continue to oppose all of the evidence raised against them.Sadly, this analysis suggests that Gulf War Syndrome is likely to prove only one of numerous such instances that are likely to emerge over the coming years.

Medically evaluated psychological and physical health of Australian Gulf War veterans with chronic fatigue

OBJECTIVE

The aim of this study was to evaluate fatigue in Australian Gulf War veterans and a military comparison group according to the 1994 chronic fatigue syndrome (CFS) definition and investigate the relation with exposures.

METHODS

Comprehensive medical, psychological and reported exposure assessments of 1,456 veterans and 1,588 comparison group in a cross-sectional study.

RESULTS

More Gulf War veterans had fatigue at all levels than did the military comparison group. The findings may be at least partly explained as an "active-deployment effect." The odds ratios increased with increasing clinical evaluation of the nature of the fatigue, even after adjustment for current psychiatric disorders in addition to other possible confounding factors.

CONCLUSION

Medically unexplained chronic fatigue was more common, but not more disabling, in veterans than in the comparison group, but veterans with unexplained chronic fatigue had poorer health than veterans without. Within both populations, CFS is uncommon and at a similar level to the general community.

Systematic review of multi-symptom conditions in Gulf War veterans

BACKGROUND

Gulf War veterans have a number of health complaints. We therefore decided to carry out a systematic review to identify and summarize the findings from studies that have assessed multi-symptom conditions in Gulf War veterans and in an unexposed comparison group.

METHOD

Studies published between January 1990 and May 2004 were identified by searching a large number of electronic databases. Reference lists and websites were also searched and key researchers were contacted. Studies were included if they compared the prevalence of chronic fatigue syndrome, multiple chemical sensitivity, CDC-defined chronic multi-symptom illness, fibromyalgia, or symptoms of either fatigue or numbness and tingling in Gulf War veterans and non-Gulf veterans. A total of 2401 abstracts were independently reviewed by two authors.

RESULTS

Twenty-three publications fulfilled the inclusion criteria. Gulf deployment was most strongly associated with chronic fatigue syndrome (OR 3.8, 95% CI 2.2-6.7). Gulf War veterans were also approximately three and a half times more likely than non-Gulf veterans to report multiple chemical sensitivity or chronic multi-symptom illness as defined by CDC. The methodological quality of the studies varied but the later and larger studies were of a high methodological standard with robust sampling strategies, adequate response rates and good adjustment for confounders.

CONCLUSIONS

The results support the hypothesis that deployment to the Gulf War is associated with greater reporting of multi-symptom conditions.

On being a Gulf veteran: an anthropological perspective

There is no doubt that Gulf service has affected the well-being of some of the members of the UK armed forces who served in that conflict, yet the reason for this remain unclear. At present, the debate surrounding Gulf War Syndrome (GWS) has become stagnant and highly polarized. This paper argues that a new perspective is needed to further improve our understanding of the problem and suggests that the methods and theories of anthropology, with its focus on nuances and subtleties, can provide new insights. Data were generated from 14 months of ethnographic fieldwork in the UK including participant observation, semi-structured interviews and document analysis. Anthropology provides a unique way of approaching and understanding somatic symptoms and suggests that GWS symptom reporting can be seen as a form of communication. The work focuses on the sufferers' accounts, the symptoms themselves and the context within which we find them in order to better understand what was being expressed and commented upon. Although necessary to contextualize GWS through situating it among other emergent illnesses and widespread health beliefs, this paper shows there is a need to bring back the particular. This work seeks to make sense of the cultural circumstances, specific and general, which gave rise to the illness.

Smaller head of the hippocampus in Gulf War-related posttraumatic stress disorder

Reductions in hippocampal volume and impairment in short-term verbal memory have been reported in Vietnam combat veterans with posttraumatic stress disorder (PTSD) and in women with abuse-related PTSD. The present investigation evaluated hippocampal volume and memory in Gulf War veterans. This research is timely given the ongoing war in Iraq and the anticipated high rates of PTSD among returning combat soldiers. Fourteen veterans with PTSD related to traumatic experiences during the Gulf War (1990-1991), 23 deployed veterans without PTSD, 22 non-deployed reservists and 29 healthy civilians were studied. Volumes of the hippocampus, temporal lobe, and whole brain were measured on coronal MRI scans, and hippocampal mediated memory function was evaluated. The head of the hippocampus was the only subregion that was significantly smaller in Gulf War veterans with PTSD than in healthy civilians. Deployed veterans with PTSD, deployed veterans without PTSD, and non-deployed reservists had significantly smaller whole hippocampal volume and lower scores on immediate and delayed verbal and visual retrieval compared with healthy civilians.

Deployment stressors, gender, and mental health outcomes among Gulf War I veterans

Findings indicate that war-zone exposure has negative implications for the postdeployment adjustment of veterans; however, most studies have relied on limited conceptualizations of war-zone exposure and focused on male samples. In this study, an array of deployment stressors that were content valid for both female and male Gulf War I military personnel was examined to elucidate gender differences in war-zone exposure and identify gender-based differential associations between stressors and mental health outcomes. While women and men were exposed to both mission-related and interpersonal stressors and both stressor categories were associated with mental health outcomes, women reported more interpersonal stressors and these stressors generally had a stronger impact on women's than on men's mental health. Exceptions are described, and implications are discussed.

Individual differences in the temporal variability of medically unexplained symptom reporting

THEORY

Non-specific or medically unexplained symptoms account for up to 35% of outpatient referrals. In contrast to the literature on affect, little is known about how people frame daily symptoms and how these patterns are influenced by individual differences.

METHOD

Three fixed occasion diary studies over an 8-day period (one on ill veterans of the Gulf War and two on healthy undergraduates) and a single cross-sectional survey (on ill Gulf War veterans) were conducted. The severity and frequency of daily symptoms were assessed in all daily diary samples, together with the Big 5 personality domains in one of the undergraduate samples and in the survey of veterans. The data were analysed using auto-correlations and hierarchical multivariate linear modelling.

RESULTS

In all the chronically ill and healthy samples, the data suggested potential cyclical patterns for symptom severity reporting. With regard to the frequency of symptom reporting, the veterans showed a pattern of constant symptom reporting. Finally, the relationship between the reported severity of symptoms was attenuated by intellect and surgency.

DISCUSSION

There is evidence that daily experiences of symptom severity are framed relative to each other and this relationship is influenced by personality. The practical implications of these findings are discussed.

War-related psychological stressors and risk of psychological disorders in Australian veterans of the 1991 Gulf War

BACKGROUND

Questions remain about the long-term health impacts of the 1991 Gulf War on its veterans.

AIMS

To measure psychological disorders in Australian Gulf War veterans and a military comparison group and to explore any association with exposure to Gulf War-related psychological stressors.

METHOD

Prevalences of DSM-IV psychological disorders were measured using the Composite International Diagnostic Interview. Gulf War-related psychological stressors were measured using a service experience questionnaire.

RESULTS

A total of 31% of male Gulf War veterans and 21% of the comparison group met criteria for a DSM-IV disorder first present in the post-Gulf War period. The veterans were at greater risk of developing post-Gulf War anxiety disorders including post-traumatic stress disorder, affective disorders and substance use disorders. The prevalence of such disorders remained elevated a decade after deployment. The findings can be explained partly as a 'war-deployment effect'. There was a strong dose-response relationship between psychological disorders and number of reported Gulf War-related psychological stressors.

CONCLUSIONS

Service in the 1991 Gulf War is associated with increased risk of psychological disorders and these are related to stressful experiences.

Gulf War Veterans’ Illnesses: A Pilot Study of the Relationship of Illness Beliefs to Symptom Severity and Functional Health Status

This investigation describes the illness beliefs of veterans regarding their Gulf War-related health concerns and investigates the relationship of these illness beliefs to physical and mental health functioning. Gulf War veterans (N = 583) presenting for evaluation at a Veteran's Affairs and Department of Defense facility completed self-report measures of symptom-related beliefs, psychosocial distress, and functional status. Hierarchical multiple regression analyses were performed to determine the extent that symptom-related beliefs impacted symptom-reporting and functional status independent of demographic factors and psychiatric illness. Several beliefs predicted physical symptom reporting and functional impairment in physical health and mental health domains after controlling for demographic variables and psychiatric illness. Gulf War veterans' illness beliefs may impact clinical outcomes. Discussing illness beliefs and providing accurate information is an important component of medical care for Gulf War veterans.

Self-reported ill health in male UK Gulf War veterans: a retrospective cohort study

BACKGROUND

Forces deployed to the first Gulf War report more ill health than veterans who did not serve there. Many studies of post-Gulf morbidity are based on relatively small sample sizes and selection bias is often a concern. In a setting where selection bias relating to the ill health of veterans may be reduced, we: i) examined self-reported adult ill health in a large sample of male UK Gulf War veterans and a demographically similar non-deployed comparison group; and ii) explored self-reported ill health among veterans who believed that they had Gulf War syndrome.

METHODS

This study uses data from a retrospective cohort study of reproduction and child health in which a validated postal questionnaire was sent to all UK Gulf War veterans (GWV) and a comparison cohort of Armed Service personnel who were not deployed to the Gulf (NGWV). The cohort for analysis comprises 42,818 males who responded to the questionnaire.

RESULTS

We confirmed that GWV report higher rates of general ill health. GWV were significantly more likely to have reported at least one new medical symptom or disease since 1990 than NGWV (61% versus 37%, OR 2.7, 95% CI 2.5-2.8). They were also more likely to report higher numbers of symptoms. The strongest associations were for mood swings (OR 20.9, 95%CI 16.2-27.0), memory loss/lack of concentration (OR 19.6, 95% CI 15.5-24.8), night sweats (OR 9.9, 95% CI 6.5-15.2), general fatigue (OR 9.6, 95% CI 8.3-11.1) and sexual dysfunction (OR 4.6, 95%CI 3.2-6.6). 6% of GWV believed they had Gulf War syndrome (GWS), and this was associated with the highest symptom reporting.

CONCLUSIONS

Increased levels of reported ill health among GWV were confirmed. This study was the first to use a questionnaire which did not focus specifically on the veterans' symptoms themselves. Nevertheless, the results are consistent with those of other studies of post-Gulf war illness and thus strengthen overall findings in this area of research. Further examination of the mechanisms underlying the reporting of ill health is required.

Responses to controlled diesel vapor exposure among chemically sensitive Gulf War veterans

OBJECTIVE

A significant proportion of Gulf War veterans (GWVs) report chemical sensitivity, fatigue, and unexplained symptoms resulting in ongoing disability. GWVs frequently recall an association between diesel and petrochemical fume exposure and symptoms during service. The purpose of the present study among GWVs was to evaluate the immediate health effects of acute exposure to chemicals (diesel vapors with acetaldehyde) with and without stress.

METHODS

In a single, controlled exposure to 5 parts per million (ppm) diesel vapors, symptoms, odor ratings, neurobehavioral performance, and psychophysiologic responses of 12 ill GWVs (GWV-I) were compared with 19 age- and gender-matched healthy GWVs (GWV-H).

RESULTS

Relative to baseline and to GWV-H, GWV-I reported significantly increased symptoms such as disorientation and dizziness and displayed significantly reduced end-tidal CO(2) just after the onset of exposure. As exposure increased over time, GWV-I relative to GWV-H reported significantly increased symptoms of respiratory discomfort and general malaise. GWV-I were also physiologically hyporeactive in response to behavioral tasks administered during but not before exposure.

CONCLUSIONS

Current symptoms among GWV-I may be exacerbated by ongoing environmental chemical exposures reminiscent of the Gulf War. Both psychologic and physiologic mechanisms contribute to current symptomatic responses of GWV-I.

Odors and sounds as triggers for medically unexplained symptoms: A fixed-occasion diary study of gulf war veterans

BACKGROUND

Both laboratory studies on healthy volunteers and epidemiological evidence from patient samples indicate that odor can act as a trigger for the reporting of medically unexplained symptoms (MUSs).

PURPOSE

The relationship between concurrent experiences of odor and MUSs has not been explored in a patient sample.

METHODS

This study used an 8-day fixed-occasion diary study, in which 17 veterans of the Persian Gulf War completed diary assessments of (a) the intensity and duration of odor and sound and (b) MUS severity.

RESULTS

The results showed that the intensity of odor was positively associated with the severity on the same day and subsequent days' symptoms, whereas the duration of odor was negatively related to the severity of MUS reporting on the same day.

CONCLUSIONS

These results are consistent with an associative mechanism underlying symptom reporting in veterans. By contrast, the duration, but not the intensity, of sound was related to the severity of MUS reporting on the same day.

The course of PTSD symptoms among Gulf War veterans: a growth mixture modeling approach

Relatively little is known about the course of PTSD symptoms over time following trauma exposure. Accordingly, this study utilized a specialized structural equation modeling approach, growth mixture modeling, to examine the trajectory of PTSD symptoms across three time points in a sample of Gulf War veterans (n at Time 1 = 2,949, n at Time 2 = 2,313, and n at Time 3 = 1,327). Results were most consistent with a two-group model suggesting that the course of PTSD symptoms following the Gulf War was best characterized by two distinct growth curves: (1) low levels of PTSD symptoms with little increase over time and (2) higher levels of initial symptoms with a significant increase over time. Thus, it appears that response to Gulf War experiences is not homogeneous, and that a subset of individuals may experience relatively more PTSD symptoms over time. In addition, men, Whites, those reporting more education, and those reporting less combat exposure had a significantly higher probability of being classified into the less symptomatic group.

Post-War Syndromes: Illustrating the Impact of the Social Psyche on Notions of Risk, Responsibility, Reason, and Remedy

The 20th century offered many examples of post-war syndromes such as Da Costa's syndrome, irritable heart, shell shock, effort syndrome, medical evacuation syndrome, post-traumatic stress disorder, and Gulf War syndrome. These post-war syndromes occur under conditions of substantial medical and scientific uncertainty, conditions that potentially magnify the impact of social context on clinical care for these syndromes. This article reviews the social circumstances surrounding four post-war syndromes. The case is made that social context has significantly impacted professional and lay perceptions of causal mediators, relevant risk factors, defining symptoms, and appropriate therapies for these syndromes. Furthermore, it is argued that social context influences what parties are held responsible for post-war syndromes, and what clinical disciplines are ultimately deemed appropriate to provide legitimate post-war illness care.

Depression in veterans of the first Gulf War and comparable military controls

Depression is a common mental disorder associated with poor health outcomes. The purpose of this study is to examine the prevalence of depression, mental health comorbidity, illness variables, and quality of life in a sample of military veterans serving during the first Gulf War. The Iowa Gulf War Case Validation Study involved face-to-face evaluations in 1999--2002 of 602 military personnel--either deployed ("deployed veterans") or eligible but not deployed ("non-deployed veterans") to the Gulf. Subjects were sampled by conducting a series of case-control studies nested within a population-based survey of 4,886 military personnel. All subjects were interviewed using the Structured Clinical Interview for DSM-IV (SCID-IV), and a series of semi-structured interviews and validated questionnaires. Best estimate psychiatric diagnoses were assigned based on all available data. One-hundred-ninety-two (32%) of the 602 surveyed veterans met criteria for a current or lifetime depressive disorder (major depression, dysthymia, depressive disorder--not otherwise specified). Depressed non-deployed veterans were more likely to be female and to have served in the Air Force than depressed deployed veterans. There were few significant differences between the depressed deployed veterans and the depressed non-deployed veterans. Depressed deployed veterans had significantly higher lifetime rates of comorbid cognitive dysfunction (55% vs. 35%), and anxiety disorders (59% vs. 33%)--mainly accounted for by specific phobias (12% vs. 2%) and posttraumatic stress disorder (33% vs. 10%)--than did depressed non-deployed veterans. Lifetime substance use disorders were significantly more frequent in deployed veterans than non-deployed veterans (70% vs. 52%), particularly alcohol disorders (68% vs. 52%). There were no differences in rates of personality characteristics, family psychiatric history, stressors, hypochondriasis, and level of functioning between the two study groups showed no significant differences. Depressive illness is frequent in military samples, as it is in the general population. The prevalence, pattern of comorbidity, and illness features were similar in deployed veterans and non-deployed veterans, suggesting that the depression suffered by both groups of veterans is qualitatively comparable. The main difference between study, groups was that depressed deployed veterans had higher rates than depressed non-deployed veterans of comorbid anxiety disorders, hypothesized to be part of the stress-related syndromes seen in those who experience combat.

Early symptom predictors of chronic distress in Gulf War veterans

Although there is evidence that specific early hyperarousal, avoidance, and emotional numbing symptoms are associated with later posttraumatic stress disorder (PTSD) symptomatology among veterans, little is known about predictors of later non-PTSD-related psychological symptoms. One and 2 years after serving in the Gulf War, 348 military reservists were assessed for severity of war zone stress, PTSD, psychological distress, and stress-mediated physical complaints. Overall PTSD symptomatology and emotional numbing and hyperarousal symptom clusters increased over time, whereas re-experiencing and avoidance symptoms showed no change. Emotional numbing and hyperarousal symptoms at 1 year predicted generalized distress, depression, anxiety, hostility, and somatic symptoms at 2 years, whereas re-experiencing and avoidance symptoms did not. Findings highlight the importance of targeting early emotional numbing and hyperarousal symptom clusters to reduce longer-term psychological distress.

Effects of posttraumatic stress disorder on cardiovascular stress responses in Gulf War veterans with fatiguing illness

Abnormal cardiovascular stress responses have been reported in Gulf War veterans with chronic fatigue. However, many of these veterans also suffer from posttraumatic stress disorder (PTSD), which could potentially explain the reported abnormalities. To test this hypothesis, 55 Gulf veterans (GVs) with chronic fatigue syndrome (CFS) or idiopathic chronic fatigue (ICF) were stratified into groups with (N=16) and without (N=39) comorbid PTSD, and were compared to healthy Gulf veterans (N=47) on cardiovascular responses to a series of stressors. The CFS/ICF with PTSD group had lower blood pressure responses to speech and arithmetic tasks, and more precipitous declines and slower recoveries in blood pressure after standing up than the controls. Similar trends in the CF/ICF group without PTSD were not significant, however. Both CFS/ICF groups had blunted increases in peripheral vascular resistance during mental tasks. However, only the veterans with comorbid PTSD had diminished cardiac output responses to the mental stressors and excessive vasodilatory responses to standing. Symptoms of posttraumatic stress were significant predictors of hypotensive postural responses, but only in veterans reporting a significant exposure to wartime stress. We conclude that comorbid PTSD contributes to dysregulation of cardiovascular responses to mental and postural stressors in Gulf veterans with medically unexplained fatiguing illness, and may provide a physiological basis for increased somatic complaints in Gulf veterans with symptoms of posttraumatic stress.

Can we prevent a second 'Gulf War syndrome'? Population-based healthcare for chronic idiopathic pain and fatigue after war

In the 1991 Gulf War less than 150 of nearly 700,000 deployed US troops were killed in action. Today, however, over 1 in 7 US veterans of the war has sought federal healthcare for related-health concerns, and fully 17% of UK Gulf War veterans describe themselves as suffering from the 'Gulf War syndrome', a set of poorly defined and heterogeneous ailments consisting mainly of chronic pain, fatigue, depression and other symptoms. Even though over 250 million dollars of federally funded medical research has failed to identify a unique syndrome, the debate regarding potential causes continues and has included oil well smoke, contagious infections, exposure to chemical and biological warfare agents, and posttraumatic stress disorder. Historical analyses completed since the Gulf War have found that postwar syndromes consisting of chronic pain, fatigue, depression and other symptoms have occurred after every war in the 20th century. These syndromes have gone by a variety of names such as Da Costa's syndrome, irritable heart, shell shock, neurocirculatory asthenia, and battle fatigue. Though the direct causes of these syndromes are typically elusive, it is clear that war sets in motion an undeniable cycle of physical, emotional, and fiscal consequences for war veterans and for society. These findings lead to important healthcare questions. Is there a way to prevent or mitigate subsequent postwar symptoms and associated depression and disability? We argue that while idiopathic symptoms are certain to occur following any war, a population-based approach to postwar healthcare can mitigate the impact of postwar syndromes and foster societal, military, and veteran trust. This article delineates the model, describes its epidemiological foundations, and details examples of how it is being adopted and improved as part of the system of care for US military personnel, war veterans and families. A scientific test of the model's overall effectiveness is difficult, yet healthcare systems for combatants and their families are already being put to pragmatic tests as troops return from war in Iraq and Afghanistan and from other military challenges.

Patient activism and the struggle for diagnosis: Gulf War illnesses and other medically unexplained physical symptoms in the US

We examine Gulf War illnesses--which include the fatigue, joint pain, dermatitis, headaches, memory loss, blurred vision, diarrhea, and other symptoms reported by Gulf War veterans--in relation to other medically unexplained physical symptoms such as multiple chemical sensitivity, chronic fatigue syndrome, and fibromyalgia. Our intent is to examine the diagnosis negotiations involved in these mysterious diseases, by showing the different forms of legitimacy involved in such interactions. Factors involved in diagnostic legitimacy are: diagnostic legitimacy in the medical community, lay acceptance of the diagnosis, uncertainty in looking for causes, and social mobilization. We conclude by noting that research may not be able to find any cause for these diseases/conditions; hence, it may be necessary to embrace medical uncertainty, and also to accept patient experience in order to facilitate diagnosis, treatment, and recovery process. Such a change can alter patients' expectations and taken-for-granted assumptions about medicine, and perhaps in turn reduce the frequency with which dissatisfied individuals form illness groups that mobilize to challenge what they see as an unresponsive medical system.

Belief in exposure to terrorist agents: reported exposure to nerve or mustard gas by Gulf War veterans

September 11 brought increased awareness that even the threat of chemical and biological terrorism can overwhelm this country's health care system. Belief in exposure to toxic agents, even when none is documented, is not uncommon in crisis and merits vigilant health care evaluation and services. This study examined risk factors (demographics, physical symptoms, clinical diagnosis, exposures, and health status) for belief in exposure to potential terrorist agents (nerve or mustard gas) using a large sample of Gulf War veterans who reported belief in exposure to nerve or mustard gas. We found that females, nonwhites, and those who were older (age 32 to 61 years) were more likely to report exposure. When adjusting for demographics and military service, these veterans reported more exposures (nonnerve or mustard gas) to potentially toxic agents and traumatic events (odds ratio [OR], 6.80; p<.001), reported more physical symptoms during the Gulf War (OR, 2.38; p<.001), were more likely to be diagnosed with a mental disorder (OR, 1.72; p<.001), and reported poorer current health status (OR, 3.47 to 1.22; p<.001). Not unlike previously reported studies of disasters, traumatic exposures, or risk exposures, belief in exposure to toxic agents suggests that certain people are at a greater health care risk. This knowledge will aid in better responding to rapid demands that may be placed on our health care delivery systems in times of potential terrorist activity.

Olfactory functioning in Gulf War-era veterans: relationships to war-zone duty, self-reported hazards exposures, and psychological distress

To explore possible neurotoxic sequelae of Gulf War (GW) participation, olfactory identification performance, neurocognitive functioning, health perceptions, and emotional distress were assessed in 72 veterans deployed to the GW and 33 military personnel activated during the GW but not deployed to the war zone. Findings revealed that war-zone-exposed veterans reported more concerns about health, cognitive functioning, and depression than did their counterparts who did not see war-zone duty. There was no evidence that performances on olfactory or neurocognitive measures were related to war-zone duty or to self-reported exposure to GW toxicants. However, symptoms of emotional distress were positively correlated with self-report of health and cognitive complaints. Results do not provide support for the hypothesis that objectively-measured sensory (i.e., olfactory) or cognitive deficits are related to war-zone participation but do underscore the increasingly demonstrated association between self-reported health concerns and symptoms of emotional distress.

Visceral and cutaneous hypersensitivity in Persian Gulf war veterans with chronic gastrointestinal symptoms

Approximately 697000 United States military personnel participated in the Persian Gulf War (PGW) between August 1990 and March 1991. By April 1997, over 25% of veterans reported chronic health complaints of underdetermined etiology. Gastrointestinal symptoms were among the most frequently reported symptoms including abdominal pain and diarrhea. The objectives of this study were (1). to determine if PGW veterans chronic abdominal pain and diarrhea exhibit visceral and cutaneous hypersensitivity, (2). to determine if these differences in pain sensitivity are significantly associated with psychological stress. A total of 12 veterans (ten males, two females) (39+/-9 years) who were deployed to the Persian Gulf were enrolled. Seven civilians without prior military experience (five males, two females) and five veterans (five males) who had previously been deployed for active combat were enrolled as controls (35+/-9 years). All 12 PGW veterans reported chronic abdominal pain and diarrhea (negative diagnostic workup) that developed during their tour of duty in the Persian Gulf region. All patients completed a battery of psychological assessments and then randomly received experimental visceral (rectal distension of 35 and 55 mmHg for 30s) and cutaneous (immersion of right foot in 45 and 47 degrees C water for 30s) pain stimuli after which they rated their pain intensity and pain unpleasantness on a continuous visual analogue scale (M-VAS) scale. The trials were repeated and the mean M-VAS scores for the two trials were recorded for each subject. In comparison to controls, PGW subjects reported statistically significant higher mean ratings of pain intensity and pain unpleasantness in response to 35 and 55 mmHg rectal distention (P<0.001) and in response to 45 and 47 degrees C water immersion (P<0.001) of the hand and foot. Results of the hierarchical regressions indicated that the psychological measures (i.e. anxiety, somatic focus) accounted for a significant amount of variance in each of the pain measures. PGW veterans who developed chronic abdominal pain and diarrhea during their tour of duty exhibit visceral hypersensitivity similar to patients with the irritable bowel syndrome. These veterans also have cutaneous hypersensitivity and higher levels of anxiety and somatic focus accounting for these differences in pain reporting.