Simon Wessely

Development of a fatigue scale

A self-rating scale was developed to measure the severity of fatigue. Two-hundred and seventy-four new registrations on a general practice list completed a 14-item fatigue scale. In addition, 100 consecutive attenders to a general practice completed the fatigue scale and the fatigue item of the revised Clinical Interview Schedule (CIS-R). These were compared by the application of Relative Operating Characteristic (ROC) analysis. Tests of internal consistency and principal components analyses were performed on both sets of data. The scale was found to be both reliable and valid. There was a high degree of internal consistency, and the principal components analysis supported the notion of a two-factor solution (physical and mental fatigue). The validation coefficients for the fatigue scale, using an arbitrary cut off score of 3/4 and the item on the CIS-R were: sensitivity 75.5 and specificity 74.5.

Population based study of fatigue and psychological distress

Abstract Abstract Objectives: To determine the prevalence of fatigue in the general population and the factors associated with fatigue. Design: Postal survey. Setting: Six general practices in southern England. Subjects: 31 651 men and women aged 18-45 years registered with the practices. Main outcome measures: Responses to the 12 item general health questionnaire and a fatigue questionnaire which included self reported measures of duration, severity, and causes of fatigue. Results - 15 283 valid questionnaires were returned, giving a response rate of 48.3%, (64% after adjustment for inaccuracies in the practice registers). 2798 (18.3%) of respondents reported substantial fatigue lasting six months or longer. Fatigue and psychological morbidity were moderately correlated (r=0.62). Women were more likely to complain of fatigue than men, even after adjustment for psychological distress. The commonest cited reasons for fatigue were psychosocial (40% of patients). Of 2798 patients with excessive tiredness, only 38 (1.4%) attributed this to the chronic fatigue syndrome. Conclusion: Fatigue is distributed as a continuous variable in the community and is closely associated with psychological morbidity.

REASONING IN DELUDED SCHIZOPHRENIC AND PARANOID PATIENTS - BIASES IN PERFORMANCE ON A PROBABILISTIC INFERENCE TASK

An experiment is described in which deluded subjects with a diagnosis of schizophrenia or of delusional disorder (paranoia) were compared with a nondeluded psychiatric control group and a normal control group on a probabilistic inference task. Factors relevant to belief formation and maintenance were investigated. Deluded subjects requested less information before reaching a decision and were more ready to change their estimates of the likelihood of an event when confronted with potentially disconfirmatory information. No differences were found between the two diagnostic groups of deluded subjects. The results are discussed in light of prevailing theories of the importance of abnormal experience rather than reasoning biases in the formation and maintenance of delusional beliefs. It is suggested that a reasoning abnormality is involved, which may coexist with perceptual abnormalities.

Health of UK servicemen who served in Persian Gulf War

BACKGROUND Various symptoms in military personnel in the Persian Gulf War 1990-91 have caused international speculation and concern. We investigated UK servicemen. METHODS We did a cross-sectional postal survey on a random sample of Gulf War veterans (Gulf War cohort, n=4248) and, stratified for age and rank, servicemen deployed to the Bosnia conflict (Bosnia cohort, n=4250) and those serving during the Gulf War but not deployed there (Era cohort, n=4246). We asked about deployment, exposures, symptoms, and illnesses. We analysed men only. Our outcome measures were physical health, functional capacity (SF-36), the general health questionnaire, the Centers for Disease Control and Prevention (CDC) multisymptom criteria for Gulf War illness, and post-traumatic stress reactions. FINDINGS There were 8195 (65.1%) valid responses. The Gulf War cohort reported symptoms and disorders significantly more frequently than those in the Bosnia and Era cohorts, which were similar. Perception of physical health and ability were significantly worse in the Gulf War cohort than in the other cohorts, even after adjustment for confounders. Gulf War veterans were more likely than the Bosnia cohort to have substantial fatigue (odds ratio 2.2 [95% CI 1.9-2.6]), symptoms of post-traumatic stress (2.6 [1.9-3.4]), and psychological distress (1.6 [1.4-1.8]), and were nearly twice as likely to reach the CDC case definition (2.5 [2.2-2.8]). In the Gulf War, Bosnia, and Era cohorts, respectively, 61.9%, 36.8%, and 36.4% met the CDC criteria, which fell to 25.3%, 11.8%, and 12.2% for severe symptoms. Potentially harmful exposures were reported most frequently by the Gulf War cohort. All exposures showed associations with all of the outcome measures in the three cohorts. Exposures specific to the Gulf were associated with all outcomes. Vaccination against biological warfare and multiple routine vaccinations were associated with the CDC multisymptom syndrome in the Gulf War cohort. INTERPRETATION Service in the Gulf War was associated with various health problems over and above those associated with deployment to an unfamiliar hostile environment. Since associations of ill health with adverse events and exposures were found in all cohorts, however, they may not be unique and causally implicated in Gulf-War-related illness. A specific mechanism may link vaccination against biological warfare agents and later ill health, but the risks of illness must be considered against the protection of servicemen.

Medically unexplained symptoms: an epidemiological study in seven specialities.

OBJECTIVES This study aimed to estimate the prevalence and risk factors for medically unexplained symptoms across a variety of specialities. METHODS A cross-sectional survey was conducted at two general hospitals in southeast London between 1995 and 1997. Eight hundred and ninety consecutive new patients from seven outpatient clinics were included. Demographic and clinical characteristic variables were assessed. RESULTS Five hundred eighty-two (65%) of the subjects surveyed returned completed questionnaires. A final diagnosis was available in 550 (62%). Two hundred twenty-eight (52%) fulfilled criteria for medically unexplained symptoms. The highest prevalence was in the gynecology clinic (66%). After adjustment for confounders, medically unexplained symptoms were associated with being female, younger, and currently employed. Psychiatric morbidity per se was not associated with the presence of medically unexplained symptoms, but was more likely in those complaining of multiple symptoms. Those with medically unexplained symptoms were less disabled, but more likely to use alternative treatment in comparison with those whose symptoms were medically explained. Patients with medically unexplained symptoms were more likely to attribute their illness to physical causes as opposed to lifestyle factors. CONCLUSIONS Medically unexplained symptoms are common across general/internal medicine and represent the most common diagnosis in some specialities. Medical behavior, training, and management need to take this into account.

The health of UK military personnel who deployed to the 2003 Iraq war: a cohort study.

BACKGROUND Concerns have been raised about the mental and physical health of UK military personnel who deployed to the 2003 war in Iraq and subsequent tours of duty in the country. METHODS We compared health outcomes in a random sample of UK armed forces personnel who were deployed to the 2003 Iraq war with those in personnel who were not deployed. Participants completed a questionnaire covering the nature of the deployment and health outcomes, which included symptoms of post-traumatic stress disorder, common mental disorders, general wellbeing, alcohol consumption, physical symptoms, and fatigue. FINDINGS The participation rate was 62.3% (n=4722) in the deployed sample, and 56.3% (n=5550) in the non-deployed sample. Differences in health outcomes between groups were slight. There was a modest increase in the number of individuals with multiple physical symptoms (odds ratio 1.33; 95% CI 1.15-1.54). No other differences between groups were noted. The effect of deployment was different for reservists compared with regulars. In regulars, only presence of multiple physical symptoms was weakly associated with deployment (1.32; 1.14-1.53), whereas for reservists deployment was associated with common mental disorders (2.47, 1.35-4.52) and fatigue (1.78; 1.09-2.91). There was no evidence that later deployments, which were associated with escalating insurgency and UK casualties, were associated with poorer mental health outcomes. INTERPRETATION For regular personnel in the UK armed forces, deployment to the Iraq war has not, so far, been associated with significantly worse health outcomes, apart from a modest effect on multiple physical symptoms. There is evidence of a clinically and statistically significant effect on health in reservists.

Comment on “Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome”

Viral Link to Chronic Fatigue Chronic fatigue syndrome (CFS) is a complex and debilitating disorder that is often linked to immune system dysfunction but whose cause(s) remain mysterious. Lombardi et al. (p. 585, published online 8 October; see the Perspective by Coffin and Stoye) now present a tantalizing new lead. In blood samples from 101 patients with well-documented CFS, over two-thirds (68) contained DNA from a recently described human gammaretrovirus, xenotropic murine leukemia virus–related virus (XMRV), which possesses sequence similarity to a murine leukemia virus. Cell culture assays confirmed that XMRV derived from CFS patient plasma and from T and B lymphocytes was infectious. Although the correlation with CFS is striking, whether the virus plays a causal role in the disorder remains to be determined. Interestingly, nearly 4% of the 218 healthy donors tested were positive for XMRV, which suggests that this virus—whose pathogenic potential is unknown—may be present in a significant proportion of the general population. Two-thirds of a sample of 101 U.S. patients with chronic fatigue syndrome harbor an infectious retrovirus in their blood cells. Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells (PBMCs) from CFS patients, we identified DNA from a human gammaretrovirus, xenotropic murine leukemia virus–related virus (XMRV), in 68 of 101 patients (67%) as compared to 8 of 218 (3.7%) healthy controls. Cell culture experiments revealed that patient-derived XMRV is infectious and that both cell-associated and cell-free transmission of the virus are possible. Secondary viral infections were established in uninfected primary lymphocytes and indicator cell lines after their exposure to activated PBMCs, B cells, T cells, or plasma derived from CFS patients. These findings raise the possibility that XMRV may be a contributing factor in the pathogenesis of CFS.

The epidemiology of fatigue: more questions than answers.

Accepted for publication February 1991 Fatigue syndromes, though recognised for some time, have recently attracted a variety of new diagnostic labels, as well as both professional and media controversy. However, most of the arguments surround the interpretation of small hospital based case-control studies using highly selected groups of patients.1 There is relative silence on population based studies, which perhaps contributes to the lack of concensus. This paper reviews the epidemiology of fatigue in the general population and in primary care and examines potential sources of bias in hospital based studies.

The prevalence and morbidity of chronic fatigue and chronic fatigue syndrome: a prospective primary care study.

OBJECTIVES This study examined the prevalence and public health impact of chronic fatigue and chronic fatigue syndrome in primary care patients in England. METHODS There were 2376 subjects, aged 18 through 45 years. Of 214 subjects who fulfilled criteria for chronic fatigue, 185 (86%) were interviewed in the case-control study. Measures included chronic fatigue, psychological morbidity, depression, anxiety, somatic symptoms, symptoms of chronic fatigue syndrome, functional impairment, and psychiatric disorder. RESULTS The point prevalence of chronic fatigue was 11.3%, falling to 4.1% if comorbid psychological disorders were excluded. The point prevalence of chronic fatigue syndrome was 2.6%, falling to 0.5% if comorbid psychological disorders were excluded. Rates did not vary by social class. After adjustment for psychological disorder, being female was modestly associated with chronic fatigue. Functional impairment was profound and was associated with psychological disorder. CONCLUSIONS Both chronic fatigue and chronic fatigue syndrome are common in primary care patients and represent a considerable public health burden. Selection bias may account for previous suggestions of a link with higher socioeconomic status.

Trends in mental illness and suicidality after Hurricane Katrina

A representative sample of 815 pre-hurricane residents of the areas affected by Hurricane Katrina was interviewed 5–8 months after the hurricane and again 1 year later as the Hurricane Katrina Community Advisory Group (CAG). The follow-up survey was carried out to study patterns-correlates of recovery from hurricane-related post-traumatic stress disorder (PTSD), broader anxiety-mood disorders and suicidality. The Trauma Screening Questionnaire screening scale of PTSD and the K6 screening scale of anxiety-mood disorders were used to generate DSM-IV prevalence estimates. Contrary to results in other disaster studies, where post-disaster mental disorder typically decreases with time, prevalence increased significantly in the CAG for PTSD (20.9 vs 14.9% at baseline), serious mental illness (SMI; 14.0 vs 10.9%), suicidal ideation (6.4 vs 2.8%) and suicide plans (2.5 vs 1.0%). The increases in PTSD-SMI were confined to respondents not from the New Orleans Metropolitan Area, while the increases in suicidal ideation-plans occurred both in the New Orleans sub-sample and in the remainder of the sample. Unresolved hurricane-related stresses accounted for large proportions of the inter-temporal increases in SMI (89.2%), PTSD (31.9%) and suicidality (61.6%). Differential hurricane-related stress did not explain the significantly higher increases among respondents from areas other than New Orleans, though, as this stress was both higher initially and decreased less among respondents from the New Orleans Metropolitan Area than from other areas affected by the hurricane. Outcomes were only weakly related to socio-demographic variables, meaning that high prevalence of hurricane-related mental illness remains widely distributed in the population nearly 2 years after the hurricane.