The persistence of fatigue in chronic fatigue syndrome and multiple sclerosis: Development of a model

The cause of chronic fatigue syndrome (CFS) is unknown. With respect to factors perpetuating fatigue, on the other hand, a model has been postulated in the literature in which behavioral, cognitive, and affective factors play a role in perpetuating fatigue. In the present study, this hypothesized model was tested on patients with CFS and on fatigued patients with multiple sclerosis (MS). The model was formulated in terms of cause-and-effect relationships and an integral test of this model was performed by the statistical technique, “structural equation modeling,” in 51 patients with chronic fatigue syndrome and 50 patients with multiple sclerosis matched for age, gender, and education. Attributing complaints to a somatic cause produced low levels of physical activity, which in turn had a causal effect on fatigue severity. Depression had to be deleted from the model. Sense of control over symptoms and focusing on bodily symptoms each had a direct causal effect on fatigue. The model showed an excellent fit for CFS patients, but was rejected for MS patients. Therefore, a new model for MS patients had to be developed in which sense of control had a causal effect on fatigue. In the MS model, no causal relationship was found between the physical state as measured by the Expanded Disability Status Score (EDSS) and fatigue or functional impairment. The present study shows that cognitive and behavioral factors are involved in the persistence of fatigue. Treatment should be directed at these factors. The processes involved in the subjective experience of fatigue in CFS were different from the processes related to fatigue in MS.     

Anxiety in children with CFS/ME

Anxiety symptoms are commonly described in children with chronic fatigue syndrome or myalgic encephalopathy (CFS/ME) but to date there has been little information on the type of anxiety children experience or the relationship between anxiety and school attendance, disability or fatigue. The aim of this study was to first describe the prevalence and type of anxiety symptoms in children with CFS/ME compared with a normal European population, and secondly to investigate the association of anxiety symptoms with age, gender, school attendance, fatigue, and physical function in paediatric CFS/ME. Data were prospectively collected on children and young people with CFS/ME referred to a large specialist CFS/ME service. One hundred and sixty-four children with CFS/ME had complete data for the Spence Children’s Anxiety Scale. Teenage girls had the highest rates of total anxiety symptoms with 38% (95% CI 27–49) over the cut off (top 10% of normal European population) and significantly higher rates of symptoms in each subscale. Younger girls were more likely to score over the cut off in separation anxiety (37%, 19–40) and social phobia (39%, 25–47). There was no evidence of association between total anxiety symptoms and: time at school, time to assessment, pain or age. Associations with fatigue and physical function were attenuated when adjusted for other variables. Although anxiety symptoms are high in CFS/ME, particularly in teenage girls, it does not appear to be associated with school attendance or other measures of disability. Separation anxiety and social phobia were the most clearly elevated in paediatric CFS/ME.     

PET study examining pharmacokinetics, detection and likeability, and dopamine transporter receptor occupancy of short- and long-acting oral methylphenidate

OBJECTIVE: The abuse potential of methylphenidate has been related to the drug's capacity to produce a rapid onset of blockade of the presynaptic dopamine transporter in the brain. An oral once-a-day osmotic controlled-release formulation of methylphenidate produces a more gradual rise in plasma methylphenidate concentration, compared with immediate-release methylphenidate. The authors hypothesized that osmotic-release methylphenidate would also produce a slower onset of blockade of the presynaptic dopamine transporter and would be associated with a lower risk for detection and likeability, compared to immediate-release methylphenidate. METHOD: Twelve healthy adults were randomly assigned to receive single doses of immediate-release methylphenidate or osmotic-release methylphenidate. Doses predicted to produce equivalent maximum concentration (C(max)) values were selected (40 mg of immediate-release methylphenidate and 90 mg of osmotic-release methylphenidate). Plasma d-methylphenidate levels and responses to detection/likeability questionnaire items were obtained hourly for 10 hours after administration of methylphenidate on two separate occasions for each subject. Dopamine transporter receptor occupancies were measured at hours 1, 3, 5, and 7 by using a carbon-11-labeled imaging agent (Altropane) and positron emission tomography. RESULTS: Despite similar C(max) values for both formulations, osmotic-release methylphenidate was associated with a longer time to maximum concentration, longer time to maximum CNS dopamine transporter occupancy, and no detection/likeability, compared with immediate-release methylphenidate. CONCLUSIONS: The findings suggest that the abuse potential of oral methylphenidate is strongly influenced by the rate of delivery and not solely by the magnitude of plasma concentration or brain transporter occupancy. These results advance understanding of the underlying central effects of methylphenidate in humans and identify a potentially less abusable methylphenidate formulation.     

Biomarkers for chronic fatigue

Fatigue that persists for 6 months or more is termed chronic fatigue. Chronic fatigue (CF) in combination with a minimum of 4 of 8 symptoms and the absence of diseases that could explain these symptoms, constitute the case definition for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). Inflammation, immune system activation, autonomic dysfunction, impaired functioning in the hypothalamic-pituitary-adrenal axis, and neuroendocrine dysregulation have all been suggested as root causes of fatigue. The identification of objective markers consistently associated with CFS/ME is an important goal in relation to diagnosis and treatment, as the current case definitions are based entirely on physical signs and symptoms. This review is focused on the recent literature related to biomarkers for fatigue associated with CFS/ME and, for comparison, those associated with other diseases. These markers are distributed across several of the body’s core regulatory systems. A complex construct of symptoms emerges from alterations and/or dysfunctions in the nervous, endocrine and immune systems. We propose that new insight will depend on our ability to develop and deploy an integrative profiling of CFS/ME pathogenesis at the molecular level. Until such a molecular signature is obtained efforts to develop effective treatments will continue to be severely limited.     

Factor analysis of symptoms among subjects with unexplained chronic fatigue: what can we learn about chronic fatigue syndrome?

OBJECTIVE: Chronic fatigue syndrome (CFS) case definitions agree that fatigue must be unexplained, debilitating and present for at least 6 months, but they differ over accompanying symptoms. Our objective was to compare the 1994 CFS case-defining symptoms with those identified by factor analysis. METHODS: We surveyed the Wichita population and measured the occurrence of 21 symptoms in 1391 chronically fatigued subjects who did not report fatigue-associated medical or psychiatric conditions. We used factor analyses to identify symptom dimensions of fatigue and cluster analysis to assign subjects to subgroups. RESULTS: Forty-three subjects had CFS. We confirmed three factors: musculoskeletal, infection and cognition-mood-sleep, essentially defined by CFS symptoms. Although factor scores were higher among CFS subjects, CFS and non-CFS distributions overlapped substantially. Three clusters also showed overlap between CFS and non-CFS subjects. CONCLUSION: CFS symptomatology is a multidimensional phenomenon overlapping with other unexplained fatiguing syndromes and this must be considered in CFS research.     

Chronic fatigue syndrome: occupation, medical utilization, and subtypes in a community-based sample

Most studies of chronic fatigue syndrome (CFS) have been based on patients recruited from primary or tertiary care settings. Patients from such settings might not be typical of patients in the general population. The present investigation involved examining individuals with CFS from a community-based study. A random sample of 18,675 respondents in Chicago was first interviewed by telephone. A group of individuals with chronic fatigue accompanied by at least four minor symptoms associated with CFS were given medical and psychiatric examinations. From this sample, a physician review group diagnosed individuals with CFS. Those diagnosed with CFS were subclassified based on a variety of categories, including duration of illness, mode of illness onset, and presence or absence of a stressful life event directly preceding onset. In addition, we examined medical utilization among those diagnosed with CFS, as well as whether individuals with CFS were disproportionately represented in health care professions. Important differences emerged on measures of sociodemographics, symptoms, and functional disability. The implications of these findings and others are discussed.     

Development of a new once-a-day formulation of methylphenidate for the treatment of attention-deficit/hyperactivity disorder: proof-of-concept and proof-of-product studies

BACKGROUND: The duration of action of the immediate-release formulation of methylphenidate hydrochloride is short (3 to 4 hours), and 3 times daily dosing is thought to maximize effectiveness across a 12-hour day. The initial sustained-release formulations of methylphenidate had reduced efficacy compared with immediate-release methylphenidate and were not well accepted. Tachyphylaxis was hypothesized to account for the reduced effects, and an ascending drug delivery pattern was proposed to overcome this acute tolerance. METHODS: Children with attention-deficit/hyperactivity disorder were evaluated in a laboratory school to characterize onset and duration of the effect of a variety of methylphenidate regimens. In a proof-of-concept study, an experimental ascending profile was established by an initial bolus followed by small increasing doses of immediate-release methylphenidate in capsules administered every 30 minutes for 8 hours. Two proof-of-product studies of a new oral once-a-day formulation to deliver methylphenidate by an osmotic pump process based on OROS (ALZA Corp, Mountain View, Calif) technology (hereafter referred to "OROS-methylphenidate") were conducted: a pharmacokinetic study and a pharmacodynamic study. RESULTS: The experimental ascending profile matched the effect of the standard regimen of methylphenidate, 3 times daily. In the pharmacokinetic study, OROS-methylphenidate treatment produced a rapid rise followed by increasing plasma concentrations that peaked 7 to 9 hours after administration. In the pharmacodynamic study, OROS-methylphenidate treatment matched the 3 times daily dosing of methylphenidate for onset and duration of efficacy. CONCLUSIONS: These studies demonstrate the translation of a basic science finding (acute tolerance to clinical doses of methylphenidate) into clinical application (the selection of a new drug delivery pattern for methylphenidate). This approach produced a new product (OROS-methylphenidate or Concerta), which proved to have the predicted rapid onset (with 1-2 hours) and long duration of efficacy (10-12 hours) after a single administration in the morning.     

Associations between neuroendocrine responses to the Insulin Tolerance Test and patient characteristics in chronic fatigue syndrome

OBJECTIVE: Subtle dysregulations of the hypothalamic-pituitary-adrenal (HPA) axis have been proposed as an underlying pathophysiological mechanism in chronic fatigue syndrome (CFS). This study attempted to assess the relationship between patient characteristics and HPA axis functioning using a neuroendocrine challenge test. METHOD: A test battery designed to assess different dimensions of CFS was given to 18 CFS patients and 17 controls. To evaluate the integrity of the HPA axis, the Insulin Tolerance Test (ITT), a centrally acting neuroendocrine challenge test, was performed on patients and controls. ACTH, salivary free cortisol and total plasma cortisol levels were assessed as a measure of the HPA axis stress response. Correlations of patient characteristics were calculated with integrated responses for all endocrine parameters. RESULTS: CFS patients had a significantly reduced area under the ACTH response curve (AUC) in the ITT. The AUC was significantly associated with the duration of CFS symptoms (r = -.592, P = .005) and the severity of fatigue symptomatology (r = -.41, P = .045). In addition, duration of CFS was correlated with the severity of fatigue symptoms (r = .38, P = .045). Similar associations were not observed for cortisol parameters. CONCLUSION: It has been postulated that neuroendocrine dysregulations observed in CFS are of an acquired nature. The results of a strong association between the integrated ACTH response and the duration of CFS emphasizes the need to consider factors known to be risk factors for the chronicity of CFS symptoms, such as profound inactivity, deconditioning and sleep abnormalities, as possible candidates for secondary causes of neuroendocrine dysregulations in CFS.     

Seasonal affective disorder presenting as chronic fatigue syndrome.

Although operational criteria have been recently proposed to better define chronic fatigue syndrome (CFS), it remains a controversial diagnosis. There are many overlapping symptoms between CFS and major depression. The author presents two patients with seasonal affective disorder, who responded to phototherapy and had previously been diagnosed as CFS. Because of the consequences of treatment, seasonal and non seasonal depression need to be ruled out in patients with chronic fatigue symptoms.     

Are fatigue symptoms and chronic fatigue syndrome following Q fever infection related to psychosocial variables?

ObjectiveFatigue is known as one of the most common long-term sequelae of Q fever infections. The study aimed to determine the prevalence of fatigue symptoms, chronic fatigue, and chronic fatigue syndrome (CFS) in a sample of patients who were exposed to Q fever (Coxiella burnetii) infection compared to controls, and to contrast Q fever patients with and without fatigue symptoms related to somatoform symptoms, hypochondriacal worries and beliefs, psychosocial complaints, and social support.MethodsCross-sectional study of 84 Q fever exposed patients from a specific region in Jena (Germany) and 85 matched controls using standardized questionnaires (MFI, SF-12, CDC-SI, SOMS, Whiteley Index, OQ-45 and F-Sozu). Diagnostic interviews were performed to validate questionnaire results in a smaller subsample.ResultsPatients who were exposed to a Q fever infection in the past indicated more fatigue symptoms and chronic fatigue than controls (54.8 vs. 20%, 32.1 vs. 4.7%) but did not show more criteria for a CFS (1 patient in each group). Q fever patients showing fatigue symptoms revealed significantly higher scores in the SOMS, the Whiteley-Index, and higher psychosocial complaints measured with the OQ-45. Their health related Quality of Life was reduced, no differences were found related to perceived social support.ConclusionAlthough in our sample fatigue symptoms were common among Q fever patients, we found no increased prevalence of CFS in contrast to several other studies. The combination of fatigue symptoms with other psychosocial symptoms/problems support the view of a biopsychosocial etiology of fatigue symptoms.     

An overview of chronic fatigue syndrome

BACKGROUND: Psychological and immunologic factors both appear to contribute to chronic fatigue syndrome (CFS). By comparing CFS with other disorders in which fatigue is a prominent symptom, the association between fatigue, psychological vulnerability, depression, and immune function may be further defined. Recent data from psychological, neurologic, and immunologic studies that address these issues are reviewed. METHOD: Articles and abstracts covering CFS and related topics of fatigue, depression, and postinfectious syndromes were identified through MEDLINE and Index Medicus (1980-1990) and by bibliographic review of pertinent review articles. RESULTS: The 1988 definition of CFS by the Centers for Disease Control encompasses several conditions in which the major characteristic is severe fatigue associated with constitutional symptoms. Several studies have identified immune dysfunction in CFS patients, but the specificity of these findings remains unclear. Most studies have shown that CFS patients, compared with other patients with chronic medical illness, experience more disabling fatigue. Some investigators have found a higher incidence of concurrent and past psychiatric illness in CFS patients compared with other medical patients, thereby suggesting an underlying psychopathology in CFS. However, other studies have not found a higher than expected incidence of past depression in CFS patients and have further shown that many CFS patients have no identifiable psychopathology. CONCLUSION: CFS appears to be a heterogenous entity. Although there may be a high coincidence of major depression in CFS, a substantial proportion of patients lack any identifiable DSM-III-R psychiatric disorder yet still manifest the syndrome, thereby suggesting it has an autonomous entity. Despite the evolving nature of our current understanding of CFS, a rational diagnostic and therapeutic approach to CFS is possible.     

Coping styles in people with chronic fatigue syndrome identified from the general population of Wichita, KS

OBJECTIVE: Studies of primary and tertiary care patients suggest that maladaptive coping styles contribute to the pathogenesis and maintenance of chronic fatigue syndrome (CFS). We assessed coping styles in persons with unexplained fatigue and nonfatigued controls in a population-based study. METHODS: We enrolled 43 subjects meeting the 1994 Research Case Definition of CFS, matching them with 61 subjects with chronic unexplained fatigue who did not meet criteria for CFS [we term them insufficient symptoms or fatigue (ISF)] and 60 non-ill (NI) controls. Coping styles and clinical features of CFS were assessed using standard rating scales. RESULTS: Subjects with CFS and ISF reported significantly more escape-avoiding behavior than NI controls. There were no differences between the CFS and ISF subjects. Among participants with CFS, escape-avoiding behavior was associated with fatigue severity, pain, and disability. CONCLUSIONS: We demonstrate significantly higher reporting of maladaptive coping in a population-based sample of people with CFS and other unexplained fatiguing illnesses defined by reproducible standardized clinical empirical means in comparison to NI controls.     

Psychological correlates of functional status in chronic fatigue syndrome

Background: The present study was designed to test a cognitive model of impairment in chronic fatigue syndrome (CFS) in which disability is a function of severity of fatigue and depressive symptoms, generalized somatic symptom attributions and generalized illness worry. Methods: We compared 45 CFS and 40 multiple sclerosis (MS) outpatients on measures of functional ability, fatigue severity, depressive symptoms, somatic symptom attribution and illness worry. Results: The results confirmed previous findings of lower levels of functional status and greater fatigue among CFS patients compared to a group of patients with MS. Fatigue severity was found to be a significant predictor of physical functioning but not of psychosocial functioning in both groups. In CFS, when level of fatigue was controlled, making more somatic attributions was associated with worse physical functioning, and both illness worry and depressive symptoms were associated with worse psychosocial functioning. Conclusions: Our findings support the role of depression and illness cognitions in disability in CFS sufferers. Different cognitive factors account for physical and psychosocial disability in CFS and MS. The SF-36 may be sensitive to symptom attributions, suggesting caution in its interpretation when used with patients with ill-defined medical conditions.     

Fatigue syndromes: a comparison of chronic "postviral" fatigue with neuromuscular and affective disorders.

Patients (n = 47) presenting to a neurological centre with unexplained chronic "postviral" fatigue (CFS) were studied prospectively. Controls were patients with peripheral fatiguing neuromuscular diseases and inpatients with major depression in a psychiatric hospital. Seventy-two percent of the CFS patients were cases of psychiatric disorder, using criteria that excluded fatigue as a symptom, compared with 36% of the neuromuscular group. There was no difference in subjective complaints of physical fatigue between all groups. Mental fatigue and fatigability was equally common in CFS and affective patients, but only occurred in those neuromuscular patients who were also cases of psychiatric disorder. Overall, the CFS patients more closely resembled the affective than the neuromuscular patients. Attribution of symptoms to physical rather than psychological causes was the principal difference between matched CFS and psychiatric controls. The symptoms of "postviral" fatigue had little ability to discriminate between CFS and affective disorder. The fatigue in CFS appeared central in origin, suggesting it is not primarily a neuromuscular illness. The implications for research and treatment of chronic fatigue are discussed.     

Unraveling the role of perfectionism in chronic fatigue syndrome: is there a distinction between adaptive and maladaptive perfectionism?

In the current study, we investigated whether the distinction between adaptive (i.e. high personal standards) and maladaptive (i.e. concern over mistakes and doubt about actions) perfectionism that has been found in the literature, is also valid in patients with chronic fatigue syndrome (CFS). We hypothesized that maladaptive, but not adaptive, perfectionism would be significantly and positively related to severity of fatigue and depression in CFS. We examined this hypothesis in a sample of 192 CFS patients using structural equation modelling (SEM). Although the two perfectionism dimensions were related to each other, results supported a model in which only maladaptive perfectionism was positively related to severity of fatigue and depression. Further, we found that depression fully mediated the effect of maladaptive perfectionism on fatigue. The results suggest that adaptive and maladaptive perfectionism are two distinct, albeit related, dimensions in CFS. Findings of this study have important implications for theory and treatment of CFS, particularly for cognitive-behavioral treatment.     

The relationship between posttraumatic stress disorder, illness cognitions, defence styles, fatigue severity and psychological well-being in chronic fatigue syndrome

This study investigated, firstly, the rate of posttraumatic stress disorder (PTSD) and the level of psychological well-being amongst people with chronic fatigue syndrome (CFS); and secondly, the extent to which illness cognitions, defence styles and PTSD symptom severity related to fatigue severity and psychological well-being. Seventy-eight participants with a diagnosis of CFS completed the Chalder Fatigue Scale, the General Health Questionnaire-28, the Posttraumatic Stress Diagnostic Scale, the Illness Cognition Questionnaire and the Defence Style Questionnaire. Fifty-nine participants were recruited from the general public to form the non-fatigued control group. CFS participants had significantly higher levels of PTSD symptoms, lower levels of psychological well-being and more traumatic life events compared to the non-fatigued controls. Trauma exposure and PTSD severity both predicted CFS status. However, regression analyses demonstrated no significant relationship between PTSD symptoms and fatigue severity or the degree of psychological well-being. ‘Helplessness’ predicted both physical and mental fatigue and psychological well-being, whilst the ‘mature’ defence styles predicted fatigue severity only. The results offer support to previous research showing that the rate of traumatic life events and PTSD are significantly higher amongst the CFS population. The lack of relationship between PTSD symptoms and fatigue severity or psychological well-being indicates that these processes may operate independently of one another, via different appraisal processes. This study focused on fatigue severity, but it may be that the role of pain in CFS is a key element in the previously reported association between PTSD and CFS.     

Monozygotic twins discordant for chronic fatigue syndrome: objective measures of sleep

PURPOSE: Chronic fatigue syndrome (CFS) is characterized by profound fatigue accompanied by disturbances of sleep, cognition, mood, and other symptoms. Our objective was to describe sleep architecture in CFS-discordant twin pairs. METHODS: We conducted a co-twin control study of 22 pairs of monozygotic twins where one twin met criteria for CFS and the co-twin was healthy. Twins underwent two nights of polysomnography. RESULTS: The percentage of Stage 3 and REM sleep was greater among the CFS twins than their healthy co-twins (P< or = .05 for both), but no other differences in sleep architecture including sleep latency, REM latency, and total sleep time were observed. Compared to their co-twins, CFS twins had higher values for the apnea-hypopnea index and apnea-hypopnea arousal index (P< or =.05 for both). CONCLUSION: These results do not provide strong evidence for a major role for abnormalities in sleep architecture in CFS. Respiration appears impaired in CFS, but these clinical abnormalities cannot alone account for the prominence of sleep complaints in this illness. The co-twin control methodology highlights the importance of selecting well-matched control subjects.     

Chronic fatigue syndrome of childhood

OBJECTIVE: To examine clinical specificity in chronic fatigue syndrome (CFS) of childhood, by comparing clinical features in childhood CFS and in emotional disorders (ED). METHOD SAMPLE: 28 children with CFS; 27 with ED. MEASURES: History of disorder; K-SADS psychiatric interviews; self-esteem and physical symptoms questionnaires; premorbid history, behavioural and personality assessments. RESULTS: There were high levels of comorbid emotional disorders in children with CFS, and the two groups were comparable on self-esteem, but CFS children endorsed more fatigue and other somatic symptoms. The two groups were comparable on age at illness onset, but parents of children with CSF reported more biological illness precipitants, more pre-morbid recurrent medical problems and infections. The CFS group had fewer pre-morbid psychological problems and less psychiatric comorbidity than the ED group. CONCLUSION: There is considerable clinical overlap between CFS and ED of childhood, but there are also differences in clinical presentation between these disorders.     

Correlates of illness worry in chronic fatigue syndrome

BACKGROUND: Anxiety about illness leading to restriction of activity and physical deconditioning has been hypothesized to contribute to the chronicity of fatigue. Pathological symptom attributions, personality traits, and depression have all been hypothesized to contribute to illness worry. METHODS: We compared 45 chronic fatigue syndrome (CFS) and 40 multiple sclerosis (MS) outpatients using a battery of psychometric instruments comprising the 12-item Illness Worry scale, the Symptom Interpretation Questionnaire (SIQ), the NEO Five-Factor Inventory (NEO-FFI), and a modified version of the SCL-90R Depression scale. RESULTS: There was no difference between the two diagnostic groups on neuroticism, depressive symptoms, as well as the three scales of the SIQ. On the illness worry index, the CFS group had significantly higher scores than the MS group. This difference was due to items tapping vulnerability to illness and the perception that others are not taking their illness seriously. Somatic attributional style, neuroticism, depressive symptoms, and age were all significant predictors of illness worry in both CFS and MS patients. CONCLUSIONS: Somatic attributions, neuroticism, and depression all contribute to illness worry in chronic illness. However, these factors do not account for the higher levels of illness worry in CFS as opposed to MS, which may be due to other specific cognitive and social interactional processes.     

Alexithymia in adolescents with chronic fatigue syndrome

BACKGROUND: Alexithymia is postulated as an important factor in the development of medically unexplained physical symptoms. Chronic fatigue syndrome (CFS) is presently medically unexplained. The aim of this study was to investigate whether the prevalence of alexithymia was higher in adolescents with CFS compared to healthy adolescents. Comorbidity such as anxiety and depression were analyzed as possible confounding factors. Secondly, alexithymia was investigated as a prognostic factor for the recovery of CFS. METHODS: A cross-sectional study was performed among 40 adolescent outpatients diagnosed with CFS and 36 healthy controls. The 20-item Toronto Alexithymia Scale was used to assess all participants for alexithymia. Additionally, all participants completed a number of questionnaires regarding fatigue (Checklist Individual Strength), somatic complaints (Checklist Somatization Inventory), depression (Children's Depression Inventory), and trait anxiety (Spielberger State Trait Anxiety Questionnaire). A follow-up study was performed among the CFS adolescents 1 1/2 years after the initial assessment. RESULTS: CFS adolescents scored higher only on the subscale identifying feelings of the TAS-20 [mean difference after adjustment for depression and anxiety 2.8 (95% CI: 0.6; 4.9]. Twelve CFS adolescents (30%) fulfilled criteria for alexithymia. This subgroup was characterized by higher scores for depression and anxiety and equal scores for fatigue and somatic complaints. At follow-up, no differences in recovery were established between the alexithymic and nonalexithymic CFS adolescents. CONCLUSIONS: Alexithymia neither appears to be a unique correlate of CFS nor to be a prognostic factor for recovery of the CFS illness.