chronic fatigue syndrome: a new challenge for health care professionals

Journal of Community Psychology Volume 23. April 199s

Chronic Fatigue Syndrome: A New Challenge for Health Care Professionals

Leonard A. Jason, Lynne Wagner, Renee Taylor, Michael T. Ropacki, Jennifer Shlaes, Joseph R. Ferrari, Susan P. Slavich, and Cheryl Stenzel

DePaul University

Chronic Fatigue Syndrome (CFS) is a new challenge to health care professionals. During the last decade, scientists have (a) created diagnostic criteria for CFS, (b) devised CFS assessment approaches, (c) collected CFS epidemiological data, and (d) formulated CFS treatment approaches. The CFS diagnostic criteria identify a subpopulation of individuals with this disorder, and those individuals might have a greater tendency to have psychiatric comorbidity. In addition, the initial CFS epidemiological data collected might have underestimated the prevalence of this disorder. If current estimated prevalence rates of CFS are inaccurate, these estimates could have detrimental public policy implications. Health care professionals need to assume a larger role in defining this syndrome, in developing more sensitive research strategies for collecting data with CFS samples, in conceptualizing more complex theories for understanding this disease, in conducting more rigorous CFS epidemiological research, and in devising more comprehensive treatment approaches for CFS.

Chronic Fatigue Syndrome (CFS) appears to be a disease that needs increased at- tention from health care professionals in its diagnosis, assessment, and treatment. CFS is an example of a complex disease syndrome with physical, psychological, social, and community implications. Psychologists who are creating a knowledge base to deal with this syndrome must deal with important questions concerning the economic, racial, and gender distributions of this disorder and the mismatch between patient needs and available models of health care delivery. These issues are critically important to those working in the field of community psychology.

The most prominent symptom of CFS is persistent fatigue for at least 6 months; other symptoms commonly reported include: mild fever or chills, sore throats, painful lymph nodes, unexplained generalized muscle weakness, muscle discomfort, prolonged generalized fatigue after levels of exercise, generalized headaches, joint pain, neuro-

The authors appreciate the help of the following people who participated in several of the CFS studies conducted at DePaul University. Dr. Judith A. Richman, an expert in psychological epidemiology, was in- strumental in helping shape the epidemiological research. Drs. A. V. Plioplys, S. Plioplys, Richmond, Paper- nik, and Lipkin were involved in the pilot CFS epidemiological project. Drs. Ann Szpindor-Watson and Greg Sharon have been involved in the studies on nurses. All seven physicians specialize in the differential diagnosis of patients presenting with CFS-related symptomology. Dr. Rademaker, a biostatistician with expertise in sample design and analysis in health-related research, has served as a consultant on this research. Dr. William McCready, Director of the Public Opinion Laboratory at Northern Illinois University, was instrumentally involved in designing and supervising the telephone screening interview procedures. Our thanks also go to Dr. Steven Goldston and Harriet Melrose for their helpful editorial comments.

The authors appreciate the financial support from The CFIDS Association of America, Minnan, Inc., and DePaul University’s University Research Council.

Requests for reprints should be sent to Leonard A. Jason, Department of Psychology, DePaul Univer- sity, 2219 N. Kenmore Ave., Chicago, IL 60614.

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psychiatric complaints, and sleep disturbances (Holmes et al., 1988a,b). CFS can affect virtually every major system in the body; neurological, immunological, hormonal, gastrointestinal and musculoskeletal problems have been reported (Jason, 1993). Bell (1991) suggests that after 2 years about 80% of CFS patients experience improvement that is due to either a lessening of the severity of symptoms, a loss of fear concerning the disease, or an alteration of life-style. Relatively few patients are cured, and most continue to experience decreases in exercise tolerance and mild symptoms related to their CFS. Periods of stress and minor illnesses exacerbate these symptoms. Wilson et al. (1994) recently recontacted 103 CFS patients after a 3Yz-year follow-up, and many remained functionally impaired (only six had completely recovered). Similarly, Steele, Reyes, and Dobbins (1994) followed up 478 CFS patients studied over a mean period of 23 months. They found that only 36 had made a full recovery, and 64% reported more symptoms over time.

In this article, we will first review some of the prominent CFS etiologic theories. Next, we will summarize diagnostic and assessment issues, then review the current CFS epidemiological literature. The development of the CFS case definition and the estima- tion of CFS prevalence rates are critical activities of the scientific community. If bias is introduced into these scientific activities, then serious difficulties might be encountered in the way CFS is conceptualized and ultimately how patients are treated.

Etiology

Friedberg (1994) has summarized several prominent explanatory models of CFS: (1) Immune Activation model - chronic overactivation of the immune system despite the absence of pathogenic agents (Patarca, Fletcher, & Klimas, 1993); (2) Psychological Maintenance model - acute infections may account for the initial phases of the illness, but longer term disability is due to activity avoidance and phobic concerns about pre- venting symptom flare-ups (Butler, Chalder, Ron, & Wessely, 1991)'; and (3) Psycho- logical Disorders as Secondary to CFS - disability is maintained by biological factors, but symptoms can trigger psychological reactions in vulnerable individuals (Friedberg & Krupp, 1994). Evidence concerning predisposing factors, psychiatric comorbidity, and biological factors is reviewed below.

Predisposing Factors A key theoretical question involves why certain individuals might be more prone

to developing this illness than others; evidence concerning predisposing psychosocial factors might elucidate this issue. Several researchers have found that stress and coping styles are related to illness (Cohen & Williamson, 1991). For example, infectious diseases caused by common germs such as streptococcus bacteria have been related to both acute and chronic stress (Meyer & Haggarty, 1962). Manuck, Cohen, Rabin, Muldoon, and Bachen (1991) found that only individuals who showed heightened catecholamine and cardiovascular reactions to stress showed suppression in their immune function in response to a 20-minute laboratory stressor. Kasl, Evans, and Niederman (1979) studied mononucleosis infection among cadets who were not immune to the disease. Cadets

'Ware and Kleinman (1992) have proposed a fourth perspective, called the psychosocial model, which posits that cultural expectations to achieve produce symptoms that release patients from obligations and pro- tect self-esteem. This model is the least frequently cited approach.

CHRONIC FATIGUE SYNDROME 145

who contracted mononucleosis were very committed to a military career, performed poorly academically, and had fathers who were described as overachievers. These studies suggest that there might be many factors, including stress, susceptibility, and coping styles, that make people candidates for infectious diseases; however, at the present time, there is no definitive evidence linking psychological states to specific immune diseases (Bower, 1991).

Several researchers have studied the relationship between personality factors and fatigue states or prolonged recovery from illness (Abbey, 1993). Montgomery (1983), for example, found that individuals with complaints of chronic fatigue in the absence of infection had higher levels of introversion and neuroticism. Imboden, Canter, and Cluff (1961) evaluated prospective military personnel before an Asian influenza epidemic. Of the 26 respondents who became ill, those 12 who had not recovered at a 3- to 6-week follow-up had higher premorbid levels of emotional disturbance and depressive vulnerability. In a recent study by Cope, Anthony, and Mann (1994), the tendency to attribute symptoms to physical disorders rather than psychological factors and a less definite diagnosis by a general practitioner were significant predictors of chronic fatigue. Blakely et al. (1991) compared CFS patients with chronic pain patients and healthy con- trols. He concluded that no unique psychological characteristics are antecedents or con- sequences of CFS, but high levels of emotionality or neuroticism may act as predisposing factors.

Finally, Lanham and Lanham (1994) found more autoimmune diseases in families of CFS patients. Autoimmune diseases are partly the result of genetic predisposition, so it is possible that people with CFS have inherited a genetic predisposition to immunologic diseases like CFS.

Psychiatric Corn orbidity Katon and Walker (1993) found that somatization disorder in CFS patients averages

10%-15%, which is at least three times higher than in other medical populations. Somatization, defined as medically unexplained symptoms, is related to underlying emotional or social difficulties. Attribution is a coping strategy patients utilize to deal with somatization, as well as other illnesses. In somatization, specifically, the patient’s focus on the body avoids the blame that would be associated with a psychological attribution (Goldberg & Bridges, 1988). Wessely and Powell (1989) found 86% of patients with postviral fatigue attributed their illness to physical factors, whereas among depressive patients, only 14% attributed their illness to such factors. Depressed patients with CFS reported less guilt and impaired self-esteem than patients with a major depressive illness. Poor outcomes for CFS patients in cognitive behavior therapy treatment programs have been associated with the attribution of physical causes for CFS (Butler et al., 1991). These studies suggest that individuals with CFS attribute their illness to external causes and such attributions might help them avoid self-blame. However, it is possible that the U.S. definition of CFS, which requires eight or more minor symptoms, selects individuals with a higher likelihood of having somatization and other psychiatric disorders (Katon & Russo, 1992). In addition, if CFS symptoms are caused by a medical illness, then these symptoms reflect a true medical illness rather than somatization. A recent study by Wood, Bentall, Gopfert, Dewey, and Edwards (1994) found no support for the hypothesis that CFS patients respond to stress with physical symptoms rather than by expressing feelings. Ray, Weir, Cullen, and Phillips (1992) found no significant rela- tion between indices of perceived CFS illness severity (e.g., frequency of symptoms,

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course of illness, disability, severity of illness) and emotional distress, and the lack of an independent relationship between these two variables could be one of the bases on which people with CFS attribute their illness to physical rather than psychological causes.

General fatigue in the population ranges from 12% to 30% (David, Wessely, & Pelosi, 1991), and some researchers believe that many cases of CFS are individuals who lie at the extreme end of this continuum (Lewis & Wessely, 1992). Some physicians believe that CFS is rare, and that most cases of self-reported CFS are due to their psychiatric disorders or other medical conditions (Manu, Lane, & Matthews, 1988). For example, fatigue is one of the most common presenting symptoms of depression. Because fatigue is present in all cases of CFS, some have suggested that depression might be the cause of CFS; however, several studies have suggested that CFS is distinct from depression. For instance, CFS patients show more alpha EEG activity during NREM sleep, but this is not seen in dysthymic or major depresive disorders (Whelton, Salit, & Moldofsky, 1992). Donati, Fagioli, Komaroff, and Duffy (1994) also found that CFS patients have EEG abnormalities that are not reflections of major depression. Bakheit, Behan, Dinan, Gray, and O’Keane (1992) found upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome but not in those with primary depression. Pepper, Krupp, Friedberg, Doscher, and Coyle (1993) found clear differences between CFS patients and patients with major depression (i.e., CFS patients had a lower incidence of schizoid, avoidant, passive-aggressive, and self-defeating personality disorders and a lower level of depressive symptoms).

In addition, some CFS-afflicted people have no premorbid history of depression. Hickie, Lloyd, Wakefield, and Parker (1990) reported premorbid prevalence rates of people with CFS to be 12.5% for major depression and 24.5% for total psychiatric disorders. These rates are similar to the general population’s, although Abbey and Gar- finkel (1991 a) have raised several questions about potentially confounding factors in this study. Others have found much higher psychiatric rates in CFS samples. Kruesi, Dale, and Straus (1989) found 75% of CFS patients had a lifetime prevalence of psychiatric problems, and 26 of 28 patients acquired chronic fatigue after the onset of psychiatric disorders. A limitation in this study is that all respondents had unusual Epstein-Barr virus (EBV) serology profiles; and Allen and Tilkian (1986) have suggested that the intensity of depressive symptoms is positively correlated with immune response to EBV infection. Wessely and Powell (1989) evaluated patients with postviral fatigue syndrome and found 72% with psychiatric disorders, and 47% were diagnosed with major depression. Katon, Buchwald, Simon, Russo, and Mease (1991) found a 77% lifetime prevalence of major depression for CFS patients. Lane, Manu, and Matthews (1991) found mood disorders during the lifetime of 75% of patients in a CFS sample, and 43% had episodes of depression at least 1 year before the onset of CFS. In the CDC prevalence study, 58% of their sample had psychological problems either prior to, during, or after the onset of fatigue (Gunn, Connell, & Randall, 1993). A study by Pepper et al. (1993) found that CFS patients did not differ from multiple sclerosis patients with regard to personality factors; however, CFS patients had significantly more frequent depression, particularly following onset of their illness. Stone et al. (1994) recently found that CFS patients did not differ from nonpatients in overall levels of positive and negative affectivity, and this finding argues against an explanation of CFS as an expression of depression.

David et al. (1991) concluded that depression occurs in about 50% of CFS cases, and anxiety and somatization disorders (somatization, minor depression, phobia, anxiety


disorders, conversion disorders) occur in about 25% of cases. It is still unclear whether these high psychiatric rates are a cause, an effect, or covary with CFS. In addition, as Krupp, Mendelson, and Friedman (1991) note, although the prevalence of psychopathology in CFS is high, it is important to remember that 25% to 35% of patients have no psychiatric condition, and this subgroup suggests that CFS cannot be completely attributable to psychological factors. Ray (1991) offers a further cautionary note by stating that many disorders have at one time been thought of in psychological terms, but these models were abandoned when somatic causes were identified. In addition, many of the samples mentioned above were selected at tertiary care facilities where individuals have longer-standing illnesses, and emotional problems might be less common in community-based samples.

Individuals with CFS might have had psychiatric problems before and/or after CFS onset, and some individuals with CFS have not experienced psychiatric problems. Those depressed prior to CFS onset may have had vulnerable coping strategies and support systems. Vulnerabilities in coping and depressive states might have negatively influenced their immune systems and, as a consequence, placed them at higher risk for developing CFS. Those without pre-existing psychiatric disorders, who develop CFS, might experience depression and other psychiatric disorders associated with the losses in terms of work and social roles, and negative coping strategies and mood disorders could hamper efforts at recovery. Some individuals with CFS who have no pre-existing psychiatric illnesses, and who are able to avoid psychiatric illness after onset of CFS, might still experience profound negative effects on their social networks and coping capacities, which could influence their recovery process. Stress, support, coping styles, and psychiatric comorbidity could be important mediators for understanding disease onset and maintenance.

Biological Factors In a recent summary of the literature, Patarca et al. (1993) found people with CFS

to have chronic immune activation, as demonstrated by elevations of activated T lymphocytes, and poor cellular function, and low NK cell cytotoxicity and frequent immunoglobulin deficiences (most often IgGl and IgG3). Typical of the research support- ing immunological problems is that of Landay, Jessop, Lennette, and Levy (1991), who found in CFS patients that the CD8 CDl lb suppressor cell population was reduced while the activation markers (CD38 and HLA-DR) had increased. This suggests that decreased suppressor cells lead to a hyperimmune response. The activation might lead to increases in other cytokines that are associated with fatigue and other signs of viral infections. Another well-known study by Demitrack et al. (1991) found low levels of cortisol in CFS patients, which might be due to a deficit of corticotropin-releasing hormone. Deficits in cortisol have been linked to lethargy and fatigue, and this deficit might be contributing to the overactive immune system. Wessely (1993), however, states that it is simplistic to view CFS as a deficiency in corticotropin-releasing factor (CRF), but some abnormality in CRF metabolism possibly underlies both depression and CFS. A recent study by Straus, Fritz, Dale, Gould, and Strober (1993) found CFS patients have memory T-cells with increased levels of adhesion markers. The increased number of memory cells with adhesion molecules appear to shift from the blood to the tissues, and these tissue-based cells escape detection by research blood tests. In the tissues, the increased number of memory cells with adhesion markers release molecules that regulate the immune response, which can cause mild inflammation and pain. Taken together this evidence may explain some

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of the complaints of CFS patients including painful muscles, joints, and tender lymph nodes. One reason for medical skepticism of CFS is many studies examining cellular immune response abnormalities in people with CFS have not been consistently reproduced (Krupp et al., 1991).

A Psychoneuroimmunologic Model All the aforementioned findings indicate that it is unclear which combination of

biological and psychiatric factors are causing and maintaining CFS. However, a psychoneuroimmunology model might provide health care professionals a heuristic framework for understanding this disease syndrome. Psychoneuroimmunologists pro- pose that the nervous, endocrine, and immune systems are in constant communication with each other (Kiecolt-Glaser & Glaser, 1989). In the mid-70s, Ader and Cohen’s (1975) pioneering work indicated that the immune system can be conditioned, suggesting that our thoughts and surroundings can cue immune enhancement or suppression. Under conditions of stress, depression, loss of control, learned helplessness, high anxiety, bereavement, loneliness, or high inhibited power motivation, reductions occur in disease- fighting immune cells (Kiecolt-Glaser, Garner, Speicher, Penn, & Glaser, 1984). Accord- ing to Kaplan (1991), a variety of factors might influence immunosuppression, including dysphoric responses (e.g., depressive affect, unhappiness, anxiety), immunosuppressive behaviors (e.g., dietary patterns, sleep habits, licit and illicit drug use), adverse life experiences (e.g., ongoing strains in interpersonal relationships), and pre-existing vulnerabilities (e.g., the absence of interpersonal resources and coping patterns to forestall the impact of negative life experiences). Many studies have provided some support for components of this theory (e.g., Clark, 1986; Pennebaker & Beall, 1986). These theoretical ideas might have important implications for understanding CFS.

After a viral infection, the brain is exposed to high levels of various cytokines. Ac- tivation by macrophages due to a virus or bacteria produces a release of interleukin 1 , which causes an alteration in electrical activity of the brain and behavioral changes (e.g . , decreases in activity, social interaction, somnolence) designed to reduce unnecessary energy expenditures, so available energy stores can be used to fight the infection (Maier, Watkins, & Fleshner, 1994). These cytokines could induce a state of chronic activation, which leads to a depletion of the stress hormone axis, and other neuropsychiatric and neuroendocrine features associated with CFS (Saphier, 1994). Some individuals might be at higher risk for developing this chronic activation, due either to genetic vulnerabilities or constitutional or psychological factors. Exacerbation of symptoms could trigger maladaptive appraisals and coping strategies, which may perpetuate symptomatic episodes via affective, neuroendocrine, and immunologic pathways (Antoni et al., 1994). There are some medical illnesses (e.g., multiple sclerosis, hyperthyroidism) that have been shown to elicit psychological disorders, and changes in mood, fatigue, and malaise are commonly associated with infection (Ray, 1991). In addition, depression can be a reaction to a physical illness, as depression and anxiety are common in patients with cancer and heart disease. Ray (1991) believes that depression that accompanies a prolonged illness may be better conceptualized as demoralization rather than a psychiatric illness, particularly in ambiguous illnesses where patients have difficulty gaining recogni- tion that they have a legitimate illness. Rather than conceptualizing CFS as solely a disease of the body or the mind, psychoneuroimmunology provides a transactional model, one which suggests that complex interactions between multiple biological and psychological factors influence the onset of CFS and pathways to further illness or recovery.


Diagnosis and Assessment

Attempts at specifying diagnostic criteria for CFS have aroused controversy (Gruffer- man, 1991). The key features of the first CFS definition (Holmes et al., 1988a) are a group of eight minor symptoms (see footnote 2), fatigue “that is severe enough to reduce or impair average daily activity below 50% of the patient’s premorbid activity level for a period of at least six months” (p. 388). and other illnesses that may produce similar symptoms are excluded.2

The definition above has been used by the Centers for Disease Control (CDC) in their CFS prevalence study, which will be reviewed later. Komaroff and Geiger (1989) and Katon et al. (1991) found that patients with CFS were indistinguishable from those with chronic fatigue not meeting the CDC criteria. One of the key problems with the current CFS definition is that it requires eight or more minor symptoms, which involve many unexplained somatic complaints like muscle pains. However, requiring a high number of unexplained somatic complaints can inadvertently select individuals with psychiatric problems (Straus, 1992). For example, Katon and Russo (1992) classified 285 chronic fatigue patients into four groups, with each group having a higher number of unexplained somatic symptoms. Patients with the highest numbers of unexplained physical symptoms had extraordinary rates of psychiatric disorders. Patients in the group with the lowest number of unexplained symptoms displayed a prevalence of psychiatric symptoms similar to that reported for other clinic populations with chronic mental illnesses. The CDC criteria for CFS inadvertently selects subgroups of patients with high levels of psychiatric diagnoses. Some professionals might overgeneralize these findings by concluding that the high degree of psychiatric comorbidity proves that CFS is really only a psychiatric disorder. Therefore, health care professionals have an important role to play in helping develop more appropriate CFS definitions and strategies for assessing CFS ~yrnptoms.~

Assessing Symptoms The following discussion will be limited to the assessment of symptoms, fatigue,

and psychiatric disorders. The current U.S. definition of CFS (Holmes et al., 1988a)

2CFS criteria include 6 or more of 11 minor symptoms (e.g., sore throat, painful lymph nodes, unexplained generalized muscle weakness) plus 2 or more of the 3 physical criteria (e.g.. low-grade fever documented by a physician); or 8 or more of 11 minor symptom criteria. At first, any psychiatric illness would be a reason for excluding a CFS diagnosis, but later several of the authors of the Holmes et a]. (l988a) report recom- mended that if the mood disorders occurred after the onset of chronic fatigue, a person could still obtain a CFS diagnosis (Holmes et al., 1988b). A second definition of CFS is a modified version of the Holmes et al.’s (1988a) criteria (Schluederberg et al., 1992). A new CDC definition is being developed, but it had not been published when this article was written.

A third set of criteria is the British definition of CFS (Sharpe et al., 1991). There is also an Australian CFS definition (Lloyd et al., 1990). An advantage of the British and the Australian definitions is that they do not require 8 or more minor symptoms, as does the CDC criteria, and as a consequence more individuals meet CFS criteria with these definitions. None of the current definitions has been empirically derived or pro- spectively contrasted with one another, although one study did find similar laboratory abnormalities among CFS patients using the three different definitions (Bates et al., 1994).

’It is probable that CFS is a heterogeneous category, and there might be different subsets of patients. For example, Hickie, Lloyd, Wilson, and Hadzi-Pavlovic (1993) found two subsets within their CFS samples: 73% consisted of a heterogeneous group with limited fatigue and neuropsychiatric symptoms, and moderate disability; and 27% had clinical characteristics of somatoform disorders, having overinclusive somatic and psychological symptoms, more illness behavior and severe psychological morbidity. Circumstances surround- ing the onset of CFS might also differentiate patients. Friedberg, MacKenzie, Dechene, and Fontanetta (1994) found that those patients who made significant improvements over time had significantly higher CFS symptoms during the first year of the illness.

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is based on a set of symptoms, which are scored using a binary classification (i.e., oc- currence versus nonoccurrence of muscle pain). Given the importance of these symptoms in defining CFS, several investigators have provided a more differentiated system that provides quantitative data using a continuum (Bell, 1991; Jason & Taylor, 1994). Such systems could provide researchers a more sophisticated methodology for classify- ing CFS. For example, two individuals might both indicate the presence of sleep disorders; however, this symptom may be relatively mild for one and severe for the other. These types of distinctions in severity might be critical for ultimately better understanding this syndrome and possibly deriving subtypes of this heterogeneous syndrome. Hence, health care professionals have a unique role to play in developing observational and rating systems for charting CFS symptoms over time, and such data might profitably be related to other psychological or biological indices.

One of the more perplexing problems facing CFS investigators is developing measures of fatigue and energy levels (Bell, 1991). Unfortunately, there are no guidelines for how to evaluate a significant reduction in activity level or energy level. Fatigue rating scales typically have been used to provide a sample describing one time point (Krupp et al., 1991). Because fatigue levels are such a prominent and defining symptom of CFS, a behavioral approach using time series methods might provide some advantages in describing fatigue in CFS (Stone et al., 1994). Jason, Holden, Taylor, and Melrose (in press) collected this type of data and found that the best way to understand fatigue is in its relationship to activity level, because some individuals with CFS experience high debilitating levels of fatigue throughout the entire day with only minor activity whereas others only experience high levels of fatigue after a period of activity, and with rest, the levels of fatigue decrease gradually. These represent two distinct patterns, and in current studies these distinct types of fatigue are collapsed. Collection of time series data might provide researchers with the clinical data to revise the current CDC definition so that relationships between energy level and activity are taken into account. Given the many symptoms of this complex disease and the changing nature of its symptoms, health care professionals could play a key role in the development of new assessment approaches to better understand CFS.

Psychiatric Assessment

The Diagnostic Interview Schedule (DIS), a structured psychiatric instrument designed for use in community surveys (Robins & Regier, 1991), has frequently been used to assess psychiatric comorbidity in CFS samples. There are, unfortunately, differences in the way that CFS investigators are administering this in~t rument .~ Additionally,

4For example, the Centers for Disease Control has significantly modified both the administration and scoring of this instrument. As an example, for the Somatization section, question D4 is a necessary question on the original DIS that has been left out of the CDC's DIS. Question D4 occurs as an integral part of the Panic Disorder section and paraphrased, it reads: [For each 5 . in Column 1, ASK: Were you ever bothered by (somatization-type symptoms) at any time other than when you were having one of these spells (panic attacks)?]. If the respondent answers yes to this question, then they could potentially meet criteria for both Somatization Disorder and Panic Disorder. If the respondent answers no, however, then he or she is only eligible to meet criteria for Panic Disorder. This is an important question in distinguishing between respondents with panic disorder only, those with somatization disorder only, and those with both Panic Disorder and Somatization Disorder. By excluding a question similar to question D4, the number of respondents with DSM-111-R Somatization Disorder may be overestimated given that many Panic Disorder symptoms may be mistaken as Somatization Disorder Symptoms. Other examples of problems with the CDC's DIS can be obtained by writing the first author.


research groups using the DIS are employing different decision rules in scoring responses and these decision rules determine whether research groups view symptoms as resulting from a medical illness or a psychiatric disorder.’ Many of the CFS minor symptoms are contained within DSM-IV categories. In other words, a person with CFS might specify a large number of physical problems, which are caused by this illness, but these physical problems also make the person eligible for a diagnosis of somatization disorder.6

Some CFS investigators (e.g., Friedberg & Krupp, 1993) use a semi-structured clinical interview based on the DSM-111-R (American Psychiatric Association, 1988). This was the instrument used by Hickie et al. (1990), who found premorbid psychiatric disorders in a sample of CFS patients no higher than general community estimates. Higher rates of psychiatric comorbidity in CFS samples have been found when using the DIS. Therefore, health care professionals could attempt to resolve this discrepancy by administering the DIS and the semi-structured clinical interview to a CFS sample and comparing the results (and such a study is currently being conducted by the research team at DePaul University).

Ray (1991) proposes that the assessment of depression needs to be carried out in more multidimensional ways. Symptoms of depression can be grouped into three categories: affective (irritability, dysphoric mood, anhedonia), cognitive (negative in- terpretations of themselves and the world), and somatic (alterations in weight, sleep patterns, increased fatigability, dry mouth, constipation, and headaches). Brickman and Fins (1993) suggested that focusing on the affective and cognitive components of CFS may allow investigators to reduce possible confounding effects of somatic symptoms. Individuals with depressive disorders often experience anhedonia, a loss of pleasure, and feelings of worthlessness, symptoms that are usually not experienced by individuals with CFS unless they have comorbid-morbid depression. In addition, CFS symptoms including prolonged fatigue after mental exertion, night sweats, recurrent joint pains, and sore throats are not commonly found in depression. In addition, mood in people who are depressed is lowest in the morning, rising if at all during the day, whereas in people with CFS, energy and mood is highest in the mid-morning (Wood, Magnello, & Sharpe, 1992).

Epidemiology

Research to date addressing epidemiological parameters of CFS has largely been confined to individual clinical settings. Many uncontrolled reports of the prevalence of CFS also exist (Shafran, 1991). Bates et al. (1993) conducted one of the better studies, which evaluated a cohort of 1 ,O00 consecutive patients in a primary care clinic. Point

’For example, if a respondent mentions that a symptom on the DIS (e.g., pains in arms or legs) was due to a medical problem that was diagnosed by a physician, DIS rules indicate this problem should not be counted as a psychiatric problem. In addition, if the respondent had no contact with a doctor, yet still claims the symptom was always the result of a physical illness or injury, the DIS directions indicate the administrator should take the respondent’s word for it (but if the interviewer believes that the respondent is probably mistaken, an editor might later recode the response to a psychiatric problem). Many CFS researchers are not following these directions, and they are coding both situations as a psychiatric problem, and thus possibly increasing the rates of psychiatric comorbidity.

6When Demitrack (1993) used a restrictive criteria that excluded symptoms attributable to CFS, 6 of 30 patients reported a lifetime history of major depression; but when using criteria that included all symptoms as behaviorally relevant, 12 of 30 patients reported a lifetime history of major depressive illness. Several other investigators have found fewer differences when comparing these different scoring systems (Abbey, 1993).

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prevalences of CFS were .3%, .4%, and 1’70, using the CDC, British, and Australian case definitions, respectively. A drawback of this study is that the sample was drawn from tertiary care centers, sites where patients are more severely ill or are more highly motivated in seeking help (Grufferman, 1991).

Summarized below are prevalence estimates from broader epidemiological studies. Lloyd, Hickie, Boughton, Spencer, and Wakefield (1990) conducted the first epidemiological study. One hundred and four local medical practitioners were first asked to identify patient cases that had chronic fatigue for at least 6 months, and where the fatigue produced significant disability in the patients’ usual daily activities. None of these patients had an alternative medical diagnosis. Twenty-six medical practitioners identified 49 patients. Forty-eight of these patients were screened further with a 50-item questionnaire forwarded by mail. To be retained in the study, patients had to report in the questionnaire moderate to severe symptoms during the last month on at least one of the two questions related to fatigue (“Excessive muscle fatigue with minor activity” and “Prolonged feeling of fatigue after physical activity lasting hours or days”) and one of the two questions related to neuropsychiatric functioning (i.e., “Loss of concentrating ability” and “Memory loss”). Based on the first two stages of case ascertainment, 42 cases qualified; and 28 cases were verified by a physician. For all 28 cases, the physician and psychiatrist reached a consensus on the diagnosis of CFS. Because none of the original 42 cases had any abnormalities on their complete blood count, renal, liver, or thyroid function tests, nor did any have an alternative diagnosis, all were classified as having CFS. With age-standardization, the CFS prevalence rate was 39.6 cases per 100,Ooo.

A possible problem in this study concerned the initial phase of patient identification. The authors recontacted 50 of the original 104 medical practitioners and asked them to review the notification procedure. Of the 43 who responded to this request, 32 had not notified cases, and 31 of them said that there were no cases in their practice. In other words, of these 50 sampled medical practitioners, only 11 notified cases. It is possible that some of the medical practitioners did not adequately survey their patients for CFS, and even the authors note that some medical officers were skeptical of the validity of CFS.

Under the direction of Walter Gunn, an ongoing epidemiological study was begun at the Centers for Disease Control (CDC) in order to determine the prevalence and incidence of CFS at four sites: Atlanta, Reno, Grand Rapids, and Wichita. Four hundred and eight physicians, recruited from 900 eligible physicians, were asked to identify their patients who had unexplained, severe fatigue for 6 months or more after a normal work- up, or patients with chronic illnesses characterized by two or more of a group of specified symptoms lasting for 6 months or more (Gunn et al., 1993). A site nurse interviewed the patients and then subjected them to a battery of tests. Four members of a Physician Review Committee reviewed the profiles independently.

To date, 337 cases have been reviewed of the original 590 (Gunn et al., 1993). Place- ment of individual cases was into one of four groups. In Group I , 26% of individuals received a diagnosis meeting the working case definition of CFS (included in this group were patients with psychiatric illnesses following onset of CFS). Individuals in Group 2 included 14% of cases who had unexplained fatigue, but their symptom number or severity did not fully meet the case definition. For Group 3, 15% of cases had evidence of a known medical illness that could cause the fatigue. In Group 4, 45% of cases had a psychological condition diagnosed prior to the onset of fatigue. The minimal prevalence


rates of CFS in the four sites (group 1) ranged from 2.0 to 7.3 individuals per 100,OOO cases (prorated for all referred patients and adjusted for an estimate of nonreferral patients, these rates would increase to 8.6 to 15.1 individuals per 100,OOO cases across the four sites). More than 80% of the CFS cases were female, primarily Caucasian, and the average age of onset for the illness was 30 years old. Gunn et al. (1 993) maintained that it is unclear whether this particular finding reflects “actual racial differences in prevalence, or is the result of referral bias or differences in utilization of the health care system” (p. 93). Furthermore, Gunn et al. (1993) claim that:

. . . because only 44% of the eligible physician population agreed to participate in the surveillance system, an unknown number of eligible patients of nonpar- ticipating physicians were not referred to the system. Additionally, it is likely that some persons experiencing unexplained fatigue have reverted to nontraditional medicine for relief of symptoms, or are not being seen by health professionals at all. The extent of this phenomenon is unknown but potentially significant. (pp.

Price, North, Wessely, and Fraser (1992) provided prevalence estimates based on a random sample collected between 1981 and 1984. The Diagnostic Interview Schedule (DIS) was the assessment instrument used when interviewing. The interview also included this fatigue question, “Has there ever been a period lasting 2 weeks or more when you felt tired out all of the time?” The reduction in usual activities item was, “Giving up usual activities for several weeks or more.” Only 7 approximations of the 11 minor criteria symptoms were available. When excluding physical illness, psychiatric illness, substance abuse, and weight loss, and including 5 out of 7 of the minor criteria, only one individual out of the entire sample would have been diagnosed with CFS (7.4 cases per l00,OOO). The studies’ most serious problem is that their case definition represents a significant departure from all standard definitions of CFS. The authors note that the lack of data on 4 of the 1 1 minor symptoms “could have artificially lowered the prevalence rate,” and because all symptoms were assessed on a lifetime basis, they might have “excluded a number of subjects with chronic fatigue that occurred at a different time from their exclusion criteria” (p. 520). An underrepresentation in the prevalence of CFS could have also occurred because respondents with psychiatric disorders were excluded. The authors conclude that these findings need to be replicated in a future study that includes: “clinical assessment and standardized data collection in general population settings,” and such a study would “provide a more precise prevalence estimate of the CFS” (p. 521).

Buchwald et al. (1994) conducted a study involving a random sample of 4,000 individuals on a HMO roster in the Seattle area. Three individuals were determined to have CFS, for a prevalence rate of 98 per 100,OOO. Unfortunately, 60% of those with chronic debilitating fatigue, which was not accounted for by medical or psychiatric conditions, refused to participate. In addition, another limitation in this study is that only individuals with access to health care are represented. Therefore, it is likely that several disadvantaged groups, without access to health care, might have been underrepresented in this sample. (In Washington state, 15% to 23% of all people in nine counties have no health insurance; Diehr et al.. 1991.)

In Great Britain, Pawlikowska et al. (1994) obtained responses from 15,283 people in the general practice register with a mailed fatigue questionnaire. The response rate was 48.3%. Of the respondents, 18.3% complained of excessive fatigue, with 4.7% of respondents reporting fatigue for at least 6 months and for 50% of the time. The cause of the fatigue was attributed to myalgic encephalomyelitis (i.e., the name given to CFS

92-93)

154 JASON ET AL.

in Great Britain) by .2% of the respondents. The authors have found that chronic fatigue is actually more common in lower social classes and that the apparent overrepresenta- tion of CFS in higher social classes might be due to selection bias (i.e., access to medical care; Wessely, personal communication, May 19, 1993). Wessely (personal communication, May 19, 1993) posits that the greatest problem in the field of CFS is the paucity of reliable epidemiological data.

Jason, Taylor et al. (1993) directly surveyed a sample of 3,400 nurses through a mailed questionnaire. Two hundred and two nurses (6To) indicated that they experienced debilitating fatigue for 6 months or longer. Twenty-three nurses (or 680 per lO0,OOO) indicated that they had CFS, and a larger group had many of the symptoms of CFS. These participants are currently in the process of having their medical records and psychiatric data evaluated by a Physician Review Team. It is important to collect epidemiological data on high-risk groups, such as nurses, who may be exposed to viruses in their work settings or who may work in stressful environments (e.g., shift work).

The CDC has recently begun a community-based survey in San Francisco. Using telephone interviewing, these investigators are planning to interview a random sample of 1,700 adults with at least 1 month of severe fatigue (L. Steele, personal communication, May 18, 1994). Unfortunately, this study involves only self-reports. Hence, it will not be possible to estimate the prevalence of CFS because of the absence of medical and psychiatric examinations.

Jason, Fitzgibbon, Taylor, et al. (1993) interviewed a random sample of 1,031 people by telephone. Five percent of the sample indicated that they had unexplained, severe fatigue for 6 months or more. Sixty-four percent of the fatigued group indicated that they had no current medical doctor overseeing their illness. Six people felt they had CFS in the past, but since they recovered, CFS could not be independently confirmed. Eleven people believed that they suffered from CFS, and two others thought it might be a pos- sibility. After being examined by a physician and interviewed by a psychiatrist, 2 individuals (.2% of the sample) were diagnosed by our physician team as currently having CFS, suggesting a prevalence rate of 200 per 100,000 (Jason, Taylor et al., 1994). In the summer of 1995, Jason and colleagues will begin a larger-scale CFS community- based study involving a sample of 26,000 randomly selected people, who will be screened using a procedure similar to those used in the pilot study.

Limitations in Existing CFS Epidemiological Studies To date, physician referrals from hospital and community-based clinics are the basis

for most CFS epidemiological studies. There are several problems with this approach (Richman, Flaherty, & Rospenda, 1994). For example, medical sociological studies have indicated that many low-income individuals do not have access to the health care system (Mechanic, 1983), and therefore it is inappropriate to formulate prevalence estimates solely from treatment facilities. Disadvantaged minorities do manifest higher levels of chronic illness, and they are less likely to receive adequate care and be counted in epidemiological studies from treatment sources (Dutton, 1986). Finally, the negative stigma of this illness, perceived to be a psychiatric disorder by some, probably inhibits some afflicted individuals from seeking help (Goffman, 1961).

David et al. (1991) summarized a survey of CFS self-help organizations and found 57% of respondents claimed they had been treated badly or very badly by their doctors. The fact that many CFS patients are suspicious of conventional medical practice is sup- ported by another survey cited in Denz-Penhey and Murdoch (1993), which found 75%


of CFS patients had gone outside of orthodox medicine to be treated for their illness. Lewis and Wessely (1992) state that among psychiatrists and physicians, fatigue is one of the least important symptoms, whereas nonprofessional samples regard it as one of the most important, and these opposite perceptions may account for some of the dissatisfaction that patients with chronic fatigue encounter when interacting with their physicians. Given this unfortunate antagonism between CFS patients and the traditional medical establishment, CFS epidemiological studies that rely on referrals from physicians at medical clinics might not accurately estimate prevalence rates, and the individuals identified in these studies might not be representative of the population of ill patients.

Most studies of CFS have found few minorities (Gunn et al., 1993) and males (Manu, Lane, & Matthews, 1992), although several atypical reports have indicated higher rates of afflicted minorities (Alisky, Iczkowski, & Foti, 1991) and males (Lloyd et al., 1990, found a female to male ratio of 1.3: 1 .O). Because women do seek health care services more than men, it is unclear whether women have higher rates of CFS or are just more visible within the health care system (Richman et al., 1994). In addition, the majority of studies indicate that CFS samples are well educated (Manu et al., 1992) and/or high achievers (Shafran, 1991). Lloyd et al. (1990) found that 53% of his sample had oc- cupations such as unskilled laborers and truck drivers, whereas only 14% were professionals. Shafran (1991) observed that high achievers who are assertive may insist on referrals until a diagnosis of CFS is made, whereas those who are less assertive may be more likely to accept being told that there is nothing wrong because the laboratory tests are normal.

Recommendations for Future CFS Epidemiological Studies There is a need to evaluate the effectiveness of recruitment procedures in contact-

ing CFS subjects. Jason, Fitzgibbon, Taylor, Johnson, and Salina (1993) conducted one study that validated recruitment procedures. They found it possible to reach the majority of a sample of individuals with CFS through the use of telephone calls. Within seven attempts to reach the individuals, it was possible to reach 93% of the CFS sample. Therefore, the use of the telephone seems to be an effective method for contacting people with CFS. Prior to initiating CFS epidemiological studies, recruitment procedures need to be validated in order to insure that the procedures are capable of reaching a high percentage of those with this syndrome.

When conducting large-scale community-based epidemiological studies, there is a need to determine which participants to select for comprehensive medical and psychiatric evaluations. Fatigue, arbitrarily defined as more than 1 month in duration, is common in the general population, occurring between 19% and 28% of the population (Kroenke, Wood, Mangelsdorff, Meier, & Powell, 1988). However, severe fatigue is less common, and CFS is even rarer because most patients do not meet the key markers (Le., 6 or more months of fatigue, no exclusionary disorders). It is possible that 5% of a community sample would have significant fatigue for 6 months, as demonstrated in studies by Jason, Taylor et al. (1994), Pawlikowska et al. (1994) (who found 4.7% of their sample to have 6 months of substantial fatigue and fatigue that lasted 50% or more of the time), and Price et al. (1992) (who found only 4.4% of their sample had both fatigue and significant reductions in their usual activities). If 5% of a sample had significant fatigue for 6 months or more, when self-report medical and other exclusionary criteria are employed, this rate might be reduced to 1 Yo, as established in Jason et al. (1994). In other words, 1% of the total population might be selected as positive on a

156 JASON ET AL.

stage 1 screen. These test positives then need medical evaluation in order to determine whether they had CFS or an exclusionary illness. None of the reviewed studies included test negatives for further evaluation; however, including such samples would enhance the validity of CFS studies attempting to estimate point prevalences (Shrout & Newman, 1989).

In population-based CFS epidemiological research, it is important to validate screening instruments utilized to identify people with a high probability of having CFS. For example, in a recent study, Jason, Ropacki, et al. (1994) recruited four groups of respondents (i.e., those with a diagnosis of CFS, Lupus, Multiple Sclerosis, and a healthy control group). All respondents were interviewed twice over a 2-week period of time with a screening instrument. The screening scale had high discriminant validity and ex- cellent test-retest and interrater reliability. Future CFS epidemiological studies need to determine the sensitivity and specificity of screening scales that identify those individuals that might have the diagnosis of CFS.

Treatment

The majority of articles in the treatment field for CFS have focused on psychotropic and pharmacological approaches to relieve symptoms (McCluskey, 1993). Most studies of antiviral agents (e.g., acycolvir; Straus et al., 1988) and immune modulators (e.g., dialyzable leukocyte; Lloyd et al., 1993; immunoglobulin; Straus, 1990) have been in- conclusive or negative; however, a recent trial with Ampligen, an antiviral and im- munomodulatory drug, reduced cognitive deficits and enhanced abilities of CFS patients to perform daily activities. Psychotropic treatments may improve symptoms of CFS, but they do not provide a cure for CFS (Berne, 1992). The treatment studies employed antidepressants at subclinical doses, which are ineffective in major depression, thus suggesting that symptom reduction is not based on an antidepressant effect. Antidepressants can function as antihistamines and anti-inflammatories, and it might be through these processes that significant relief of some symptoms (e.g., pain, sleep disorders) occurs (Berne, 1992).

Psychological Factors Blakely et al. (1991) found CFS patients have a tendency to use escape/avoidance

(in females) and distancing (in males); these strategies are negatively correlated with health status. Schmall (1992) found that positive reappraisal in a CFS sample was positively correlated with measures of psychological well-being, whereas escape-avoidance and accepting responsibility were negatively correlated with well-being. Antoni et al. (1994) found that those CFS patients who used more maladaptive cognitive appraisals and more frequent use of disengagementldenial coping strategies evidenced greater disturbance in physical and psychosocial domains. Antoni et al. (1994) suggest that those CFS patients who respond to ongoing stress with distorted appraisals, denial, and avoidance coping strategies may experience significant disruptions in their social relationships. A study with similar findings was completed by Ray et al. (1992), who found that negative emotions can exacerbate CFS symptoms, and these symptoms can then increase emotional distress. Wilson et al. (1994) suggest that CFS patients who deal with distress by somatization and who discount the possible modulating role of psychosocial factors are more likely to have an unfavorable outcome.

Ray, Weir, Stewart, Miller, and Hyde (1993) evaluated problem-solving strategies in a CFS sample. They found maintaining one’s activity protected the person with CFS


from severe impairments in everyday functioning, but the cost was increased anxiety. Accommodating to the illness (Le., accepting one’s limitations and making allowances for them) safeguarded emotional functioning at the expense of functional impairment. These two strategies might represent alternative ways of compensating for an illness by increasing efforts or reducing activities and lowering demands. Individuals with CFS might alternate in using these strategies at different times. A third problem-solving strategy, focusing on symptoms, had negative implications for both impairment and emotional adjustment.

Cognitive Behavioral Interventions Several articles (Burke, 1992; Butler et al., 1991; Denz-Penhey & Murdoch, 1993;

Hayden, 1991; Lloyd et al., 1993; Rikard-Bell & Waters, 1992; Sharpe, 1993) describe the use of cognitive and psychological therapeutic techniques in overcoming CFS symptoms. Friedberg (1994) maintains that psychotherapeutic interventions for people with CFS should include an empathic response to the patient’s symptoms, relaxation train- ing to reduce stress and tension, cognitive-behavioral interventions to reduce depression and anxiety in cases of comorbid depression, identification of relapse triggers, and prescriptions for activity modification to minimize relapse. In an outcome study using this cognitive-behavioral intervention, Friedberg and Krupp (1994) found that CFS patients reporting more depressive symptoms showed significant reductions in symptoms of depression, stress, and fatigue severity. Even though the more severely depressed group of CFS patients showed considerable improvement, their fatigue severity still remained abnormally high. In other words, even though the cognitive approach was effective in reducing catastrophic thinking and symptom magnification for the depressed CFS group, fatigue severity remained elevated. These findings are important because they suggest that for CFS patients, relieving the depression does not cure the fatigue symptoms. This is the only treatment study that separated CFS patients into depressed and nondepressed groups.

Graded activity exercise schedules have been important treatment components of several studies (e.g., Butler et al., 1991; Lloyd et al., 1993). Friedberg (1994) maintains that this treatment “would appear to be appropriate if activity was avoided due to depressed mood and unrealistic fear of symptom flare-ups. However, for those CFS individuals who do not have psychologically-mediated reductions in activity, such a directed approach might be inappropriate and perhaps counterproductive.” Friedberg and Krupp (1994), found there was no evidence that exercise avoidance had become a phobically mediated behavior. Friedberg and Krupp (1994) had to encourage many of their respondents to rest rather than exert themselves and risk setbacks. They further note that there appears to be, an activity ceiling for CFS patients, and many were already performing near their ceiling. If a graded activity schedule had been introduced beginning at their current baseline levels, many would have exceeded their threshold levels. The patients were assisted in rejecting obligations that previously exhausted them and were encouraged to devote more time to neglected premorbid activities (e.g., personal care, enjoyment, relaxation). Burke et al. (1991) maintain that this approach does not help patients overcome their disability, as they believe that graded activity exercise schedules are needed treatment components for treating this syndrome. Clearly, the way in which investigators conceptualize this disorder will influence the types of treatment programs that are designed. There exists a clear need for treatment studies to compare these different strategies in order to help resolve this controversy.

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Discussion and Recommendations

Attempts to specify diagnostic criteria for CFS have aroused considerable controversy. The U.S. definition of CFS (Holmes et al., 1988b) selected a subgroup of patients that might have had a high probability of having psychiatric comorbidity. There is a need to consolidate and make recommendations concerning the different methods being used to assess psychiatric comorbidity. At the present time, it is difficult to compare studies across sites because of differences in scoring and administration of the psychiatric instruments. In addition, because this disease is one of exclusion, and energy level and symptoms play such a prominent role, a behavioral approach using time series methods might help investigators better define the disease.

Most CFS epidemiological studies have found few minorities and an overrepre- sentation of females (Gunn et al., 1993). However, most past epidemiological studies have relied on referrals from physicians or treatment centers. These studies might under- represent disadvantaged minorities who have been shown to manifest higher levels of chronic illness while additionally being less likely to receive adequate care. Thus, this group is less likely to be counted in epidemiological rates derived from treatment sources (Dutton, 1986). In addition to individuals with CFS who might not have the economic resources to have access to medical care, other people with CFS might be reluctant to use medical personnel, particularly if they have encountered physicians skeptical of the authenticity of their illness. In general, physicians who are skeptical of the existence of the CFS disease syndrome might not identify cases.

The prevalence of CFS is unclear. In the CDC’s booklet “The Facts About CFS,” the prevalence of CFS was estimated to be from 2 to 10 per 100,000 or 3,873 to 19,365 people in the United States (based on the number of people in the United States who are 18 years of age or older; 193,650,000; Statistical Abstract of the United States, 1994). Price et al.’s (1992) and Gunn et al.’s (1993) research would support these findings. However, if Lloyd et al. (1990) are correct, then there would be 76,685 people afflicted. Serious methodological problems occur in these studies, and these problems might have led to prevalence rates that underestimate the number of people afflicted with this disease. These rates also seem discrepant with the unusually high number of telephone calls (up to 3,000 a month) that the CDC receives from people who are requesting information about CFS (McCluskey, 1993, p. 288). The findings of Buchwald et al. (1994), Jason, Taylor et al. (1994), and Bates et al. (1994) suggest that there might be either 189,777; 387,300; or 580,950 people with CFS. Lloyd and Pender (1992) estimated that the an- nual direct and indirect cost to the community for each afflicted person per year is $9,436. If there are hundreds of thousands of people afflicted with this disease, then more resources, at the federal, state, and local levels, need to be devoted to finding the causes of CFS and developing appropriate treatments. In summary, existing studies of CFS, whether clinical or epidemiological, have lacked the ability to depict either the overall magnitude of CFS in the general population or its relative distribution across important sociodemographic groups such as low socioeconomic status groups with inadequate access to health care treatment.

Wessely (1990) suggests that myalgic encephalomyelitis (the term used for CFS in Great Britain) had its origins in the last century, with the condition known as neurasthenia. George Beard, an American neurologist, was responsible for publicizing this disease, beginning in 1869 (Beard, 1869). He claimed neurasthenia was a disease of profound fatigability of the body and mind, and entirely organic. Weir Mitchell,


a fellow neurologist, proposed a rest cure, and private sanatoria were established offering this treatment in this country. By the late 1800s, neurasthenia was one of the most frequently diagnosed illnesses; however, by World War I, the diagnosis of neurasthenia almost disappeared. According to Wessely (199O), this occurred because (a) medical skepticism concerning this illness increased, (b) neurasthenia began to be viewed as psychiatric rather than neurological, (c) increasing psychiatric sophistication led to further doubt about neurasthenia, and (d) it became seen as an illness of the lower social classes. Neuras- thenia patients were held in low esteem by medical personnel, and many physicians believed that neurasthenics were suffering from depression or other psychiatric conditions.

It is unclear whether the illness now known as CFS was less prevalent from WWI to the early 1980s, or whether physicians were less likely to diagnose it and patients were less likely to bring their complaints to physicians who tended to perceive their complaints in psychiatric terms. The debate that occurred about 100 years ago, concerning whether neurasthenia was a disease of the body or mind, has reappeared with CFS. For example, Manu (cited in Abbey, 1993) stated “the difference [between CFS and neurasthenia] seems to be that in the 19th century, patients with neurasthenia were able to enjoy a physical diagnosis for about 30 years. Now, research demonstrating the high prevalence of major depression among these patients has taken the physical explanation away from them, by pointing out that this might simply be an affective disorder” (p. 252). Abby and Garfinkel (1991b) wrote: “Chronic Fatigue Syndrome will meet the same fate as neurasthenia-a decline in social value as it is demonstrated that the majority of its sufferers are experiencing primary psychiatric disorders or psychophysiological reactions and that the disorder is often a culturally sanctioned form of illness behavior” (p. 1638). As has been argued in this article, conceptualizing CFS solely as a disease of the mind is excessively simplistic. CFS is probably a disease that has a complex set of psychological and biological precipitating and maintaining conditions.

Individuals with CFS are overwhelmingly tired, and in an effort to conserve energy, particularly during the worst phases, many isolate themselves from friends, family, and work. For many people with CFS, a 1-hour monthly self-help group is all that is available. Antoni et al. (1994) suggest that those CFS patients who engage in self-blame and avoid discussions about physical limitations may experience a sense of social isolation that is distressing. As a result, without the buffering effects of social support, they might amplify the degree to which they perceive their lives to have been comprised by their fatigue. Individuals with CFS who report that their conditions had improved over time had made positive changes in their social situation (e.g., changed jobs, were reunited with their family, etc.) (Ware & Kleinman, 1992). This finding suggests that health care professionals could have an important role to play in developing treatment programs that include a broader array of environmental support systems for individuals with CFS (Jason, 1993; Jason, Fitzgibbon et al., 1993).

There is a clear need to better define the CFS syndrome and develop better ways to gather epidemiological data. If both biological and psychological mechanisms are involved in this disease, then research investigators might need to seek answers to this question in interactions among complex systems involving the mind and body. The ways in which this disorder is conceptualized will have important implications for how research is designed and, ultimately, how people with CFS are treated. It is unfortunate that people with CFS often encounter stigmatizing beliefs and attitudes that can lead to further trauma (Berne, 1992). Ultimately, better controlled and sophisticated theories and research might influence sociocultural factors (i.e., the pre-existing cultural climate toward

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disease, cultural intolerance of ambiguity and chronic illness) that affect CFS patients (Fennell, 1994).

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