Fatigue in the chronic fatigue syndrome: a cognitive phenomenon?

Two-month period of 500 mg lecithin-based delivery form of quercetin daily dietary supplementation counterbalances chronic fatigue symptoms: A double-blind placebo controlled clinical trial

BACKGROUND

Chronic fatigue (CF) is a complex phenomenon without clear etiology that may require long-term treatment, but to date, no specific therapy has been identified for it. Some botanicals might be helpful in the management of CF. Among these botanicals, quercetin demonstrates its capacity to modulate multiple biological pathways and acknowledged major properties in CF: antioxidant, anti-inflammatory, immunomodulating, improving exercise endurance, enhancing mitochondrial biogenesis, repairing mitochondrial dysfunction.

PURPOSE

Given this background, the aim of this study was to evaluate if a 2-month period of daily Quercetin Phytosome™ 500 mg supplementation is of benefit for the relief of CF.

METHODS

The primary end point has been the evaluation of fatigue, by Fatigue Impact Scale (FIS-40). The secondary end points have been the assessment of sleep, by Pittsburgh Sleep Quality Index (PSQI), evaluation of muscle performance, by short physical performance battery and by wearable armband-shaped sensor in order to evaluate the number of steps, body composition, by DXA and quality of life by Short-Form 12-Item Health Survey (SF-12).

RESULTS

Seventy-eight subjects (42 F; 36 M) (mean age 56 ± 9) reporting CF symptoms, completed the study (placebo/supplement 38/40). The FIS-40 mean difference changes between groups (supplement minus placebo) was - 10.583 points (CI95% -11.985; -9.182) (p < 0.001). Also, statistically significant changes between groups have been recorded in Pittsburgh Sleep Quality Index - 2.040 points (CI95%: -2.770; -1.309), p < 0.01), number of steps 1443.152 (CI95%: 1199.556; 1686.749), and SPPB (score) 0.248 (CI95%: 0.105; 0.391) (p < 0.001).

CONCLUSION

The quercetin supplementation counterbalances CF symptoms.

An exploratory study of discrepancies between objective and subjective measurement of the physical activity level in female patients with chronic fatigue syndrome

OBJECTIVE

To explore the ability of a self-report activity diary to measure the physical activity level (PAL) in female patients with chronic fatigue syndrome (CFS) and whether illness-related complaints, health-related quality of life domains (HRQOL) or demographic factors are associated with discrepancies between self-reported and objectively measured PAL.

METHODS

Sixty-six patients with CFS, recruited from the chronic fatigue clinic of a university hospital, and twenty matched healthy controls wore an accelerometer (Actical) for six consecutive days and registered their activities in an activity diary in the same period. Participants' demographic data was collected and all subjects completed the CFS Symptom List (illness-related complaints) daily and Short-Form-36 (HRQOL domains) during the first and second appointment.

RESULTS

A significant, but weak association between the activity diary and Actical was present in patients with CFS (r_s = 0.376 and r_s = 0.352; p < 0.001) and a moderately strong association in healthy controls (r_s = 0.605; and r_s = 0.644; p < 0.001) between week and weekend days, respectively. A linear mixed model identified a negative association between age and the discrepancy between the self-reported and objective measure of PA in both patients with CFS and healthy controls.

CONCLUSION

The activity diary showed limited ability to register the PAL in female patients with CFS. The discrepancy between measures was not explained by illness-related complaints, HRQOL domains or demographic factors. The activity diary cannot replace objective activity monitoring measured with an accelerometer, but may provide additional information about the perceived activity.

Human Error: The Impact of Job Insecurity on Attention-Related Cognitive Errors and Error Detection

(1) Background: Work-related stress is a major contributor to human error. One significant workplace stressor is job insecurity, which has been linked to an increased likelihood of experiencing burnout. This, in turn, might affect human error, specifically attention-related cognitive errors (ARCES) and the ability to detect errors. ARCES can be costly for organizations and pose a safety risk. Equally detrimental effects can be caused by failure to detect errors before they can cause harm. (2) Methods: We gathered self-report and behavioral data from 148 employees working in educational, financial and medical sectors in China. We designed and piloted an error detection task in which employees had to compare fictitious customer orders to deliveries of an online shop. We tested for indirect effects using the PROCESS macro with bootstrapping (3) Results: Our findings confirmed indirect effects of job insecurity on both ARCES and the ability to detect errors via burnout. (4) Conclusions: The present research shows that job insecurity influences making and detecting errors through its relationship with burnout. These findings suggest that job insecurity could increase the likelihood for human error with potential implications for employees' safety and the safety of others.

Fatigue Is Associated With Altered Monitoring and Preparation of Physical Effort in Patients With Chronic Fatigue Syndrome

BACKGROUND

Chronic fatigue syndrome (CFS) is characterized by disabling fatigue, which is suggested to be maintained by dysfunctional beliefs. Fatigue and its maintenance are recently conceptualized as arising from abnormally precise expectations about bodily inputs and from beliefs of diminished control over bodily states, respectively. This study used functional neuroimaging to identify the neural correlates of fatigue and its maintenance by beliefs during a physical effort task.

METHODS

We isolated behavioral adjustments and cerebral activity during feedback processing and motor preparation, in the context of a task in which patients with CFS (n = 85) and healthy control subjects (n = 29) produced 30%, 50%, and 70% of their right-hand maximal voluntary contraction, and received directional feedback on performance (e.g., too little force).

RESULTS

Patients with CSF showed an effort-dependent behavioral bias toward less effort investment in response to directional feedback for the highest effort level as compared with healthy control subjects. This bias was associated with reduced feedback-related activity in the dorsolateral prefrontal cortex. These effects were proportional to state-related fatigue and prior beliefs about CFS patients' ability to perform the task. Patients with CFS also showed higher activity in the supplementary motor area, proportional to their state-related fatigue, and reduced connectivity between the supplementary motor area and sensorimotor cortex during motor preparation as compared with control subjects.

CONCLUSIONS

These findings link fatigue symptoms to alterations in behavioral choices on effort investment, prefrontal functioning, and supplementary motor area connectivity, with the dorsolateral prefrontal cortex being associated with prior beliefs about physical abilities.

Do changes in illness perceptions, physical activity, and behavioural regulation influence fatigue severity and health-related outcomes in CFS patients?

OBJECTIVE

Examine to what extent changes in cognitions and changes in physical activity and behavioural regulation patterns influence fatigue severity, physical symptoms, and physical and psychological functioning of patients suffering from Chronic Fatigue Syndrome (CFS) at follow-up.

METHODS

The present study is an observational longitudinal study with a 12-month follow-up. A total of 144 CFS patients participated both at baseline and at follow-up. Four separate hierarchical regression analyses were conducted with fatigue, physical symptoms, physical functioning and psychological functioning at follow-up as the dependent variables, and (changes in) illness perceptions and behavioural regulation patterns (all-or-nothing and limiting behaviour) as the independent variables. Data were collected making use of self-report questionnaires.

RESULTS

Increased Consequence and Identity beliefs over time, as well as increases in all-or-nothing behaviour predicted higher fatigue severity at follow-up. Both number and severity of physical symptoms and psychological functioning at follow-up were only determined by changes in illness perceptions, with increased Consequence beliefs influencing both outcomes, and increased Timeline beliefs only determining physical symptoms. Physical functioning at follow-up was predicted by changes in illness perceptions as well as increased levels of both all-or-nothing and limiting behaviour.

CONCLUSION

The findings point at a differential pattern of associations between changes in illness perceptions and behaviour regulation patterns on the one hand, and patient outcomes on the other hand. Whereas illness perceptions significantly contribute to each of the outcomes, behaviour regulation patterns contribute only to fatigue severity and physical functioning.

Investigating neural mechanisms of change of cognitive behavioural therapy for chronic fatigue syndrome: a randomized controlled trial

BACKGROUND

Chronic fatigue syndrome (CFS) is characterized by profound and disabling fatigue with no known somatic explanation. Cognitive behavioral therapy (CBT) has proven to be a successful intervention leading to a reduction in fatigue and disability. Based on previous neuroimaging findings, it has been suggested that central neural mechanisms may underlie CFS symptoms and play a role in the change brought on by CBT. In this randomized controlled trial we aim to further investigate the neural mechanisms that underlie fatigue in CFS and their change by CBT.

METHODS/DESIGN

We will conduct a randomized controlled trial in which we collect anatomical and functional magnetic resonance imaging (MRI) measures from female CFS patients before and after CBT (N = 60) or waiting list (N = 30) and compare these with measures from age and education matched healthy controls (N = 30). By including a large treatment group we will also be able to compare patients that benefit from CBT with those that do not. In addition, to further investigate the role of endocrine and immune biomarkers in CFS, we will determine cortisol and cytokine concentrations in blood, hair and/or saliva.

DISCUSSION

This project creates an unique opportunity to enhance our understanding of CFS symptoms and its change by CBT in terms of neuroanatomical, neurofunctional, endocrinological and immunological mechanisms and can help to further improve future treatments strategies.

TRIAL REGISTRATION

Dutch Trial Register #15852. Registered 9 December 2013 ( http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4311 ).

Dimensions of pure chronic fatigue: psychophysical, cognitive and biological correlates in the chronic fatigue syndrome

OBJECTIVES

To investigate associated dimensions of fatigue regarding cognitive impairment, psychomotor performances, muscular effort power and circulating cytokine levels and their relations to symptom intensity in a sample of pure chronic fatigue syndrome (CFS) patients without overlapping objective sleepiness or sleep disorders.

METHODS

16 CFS patients were compared to 14 matched controls. We assessed structured symptom-scales, polysomnography, multiple sleep latency tests, attention (Zazzo-Cancellation ZCT, digit-symbol-substitution DSST), psychomotor vigilance and speed (PVT, finger tapping test, FTT), dynamometer handgrip force (tonic and phasic trials) and circulating cytokines (IFN-γ, IL-1b, IL-6, IL-8, IL-10, TNF-α).

RESULTS

In addition to fatigue, CFS patients presented with higher affective symptom intensity and worse perceived sleep quality. Polysomnography showed more slow-wave sleep and microarousals in CFS but similar sleep time, efficiency and light-sleep durations than controls. Patients presented with impaired attention (DSST, ZCT), slower reaction times (PVT) but not with lower hit rates (FTT). Notwithstanding lower grip strength during tonic and phasic trials, CFS also presented with higher fatigability during phasic trials. Cytokine levels were increased for IL-1b, IL-8, IL-10 and TNF-α and fatigue intensity was correlated to grip strength and IL-8.

CONCLUSIONS

In contrast to sleepiness, chronic fatigue is a more complex phenomenon that cannot be reduced to one single measured dimension (i.e., sleep propensity). Showing its relations to different measurements, our study reflects this multidimensionality, in a psychosomatic disorder such as CFS. To obtain objective information, routine assessments of fatigue should rule out sleepiness, combine aspects of mental and physical fatigue and focus on fatigability.

The process of cognitive behaviour therapy for chronic fatigue syndrome: which changes in perpetuating cognitions and behaviour are related to a reduction in fatigue?

OBJECTIVE

Cognitive behaviour therapy (CBT) can significantly reduce fatigue in chronic fatigue syndrome (CFS), but little is known about the process of change taking place during CBT. Based on a recent treatment model (Wiborg et al. J Psych Res 2012), we examined how (changes in) cognitions and behaviour are related to the decrease in fatigue.

METHODS

We included 183 patients meeting the US Centers for Disease Control criteria for CFS, aged 18 to 65 years, starting CBT. We measured fatigue and possible process variables before treatment; after 6, 12 and 18 weeks; and after treatment. Possible process variables were sense of control over fatigue, focusing on symptoms, self-reported physical functioning, perceived physical activity and objective (actigraphic) physical activity. We built multiple regression models, explaining levels of fatigue during therapy by (changes in) proposed process variables.

RESULTS

We observed large individual variation in the patterns of change in fatigue and process variables during CBT for CFS. Increases in the sense of control over fatigue, perceived activity and self-reported physical functioning, and decreases in focusing on symptoms explained 20 to 46% of the variance in fatigue. An increase in objective activity was not a process variable.

CONCLUSION

A change in cognitive factors seems to be related to the decrease in fatigue during CBT for CFS. The pattern of change varies considerably between patients, but changes in process variables and fatigue occur mostly in the same period.

The role of the therapeutic relationship in cognitive behaviour therapy for chronic fatigue syndrome

Cognitive behaviour therapy (CBT) for chronic fatigue syndrome (CFS) can reduce fatigue and impairment. Recently, it was found that changes in fatigue-perpetuating factors, i.e. focusing on symptoms, control over fatigue, perceived activity and physical functioning, are associated with and explain up to half of the variance in fatigue during CBT for CFS. The therapy relationship, e.g. outcome expectations and working alliance, may also contribute to treatment outcome. We aimed to examine the role of the therapy relationship in CBT and determine whether it exerts its effect independently of changes in fatigue-perpetuating factors. We used a cohort of 217 CFS patients in which the pattern of change in fatigue-perpetuating factors was examined previously. Fatigue, therapy relationship and fatigue-perpetuating factors were measured at the start of therapy, three times during CBT and at the end of therapy. Baseline outcome expectations and agreement about the content of therapy predicted post therapy fatigue. A large part of the variance in post-treatment fatigue (25%) was jointly explained by outcome expectations, working alliance and changes in fatigue-perpetuating factors. From this, we conclude that positive outcome expectations and task agreement seem to facilitate changes in fatigue-perpetuating factors during CBT for CFS. It is therefore important to establish a positive therapy relationship early in therapy.

Towards an evidence-based treatment model for cognitive behavioral interventions focusing on chronic fatigue syndrome

OBJECTIVE

The purpose of the present study was to develop a treatment model for cognitive behavioral interventions focusing on chronic fatigue syndrome (CFS) based on the model of perpetuating factors introduced by Vercoulen et al. [Journal of Psychosomatic Research 1998;45:507-17].

METHODS

For this purpose, we reanalyzed the data of a previously conducted randomized controlled trial in which a low intensity cognitive behavioral intervention was compared to a waiting list control group. Structural equation modeling was used to test a treatment model in which changes in focusing on symptoms, perceived problems with activity, and sense of control over fatigue were hypothesized to mediate the effect of our intervention on fatigue severity and disability.

RESULTS

In the final model, which had a good fit to the data, the effect of treatment was mediated by a decrease in perceived problems with activity and an increase in sense of control over fatigue.

CONCLUSION

Our findings suggest that cognitive behavioral interventions for CFS need to change the illness perception and beliefs of their patients in order to be effective.

The central role of cognitive processes in the perpetuation of chronic fatigue syndrome

OBJECTIVE

Chronic fatigue syndrome (CFS) is considered to be one of the functional somatic syndromes (FSS). Cognitions and behavior are thought to perpetuate the symptoms of CFS. Behavioral interventions based on the existing models of perpetuating factors are quite successful in reducing fatigue and disabilities. The evidence is reviewed that cognitive processes, particularly those that determine the perception of fatigue and its effect on behavior, play a central role in the maintenance of symptoms.

METHOD

Narrative review.

RESULTS

Findings from treatment studies suggest that cognitive factors mediate the positive effect of behavioral interventions on fatigue. Increased fitness or increased physical activity does not seem to mediate the treatment response. Additional evidence for the role of cognitive processes is found in studies comparing the subjective beliefs patients have of their functioning with their actual performance and in neurobiological research.

CONCLUSION

Three different cognitive processes may play a role in the perpetuation of CFS symptoms. The first is a general cognitive representation in which fatigue is perceived as something negative and aversive and CFS is seen as an illness that is difficult to influence. The second process involved is the focusing on fatigue. The third element is formed by specific dysfunctional beliefs about activity and fatigue.

An investigation into the cognitive deficits associated with chronic fatigue syndrome

This study addresses, among other things, the debate as to whether cognitive deficits do occur with a diagnosis of Chronic Fatigue Syndrome (CFS). Previous studies have indicated a potential mismatch between subjective patient ratings of impairment and clinical assessment. In an attempt to tackle some of the methodological problems faced by previous research in this field, this study recruited a large sample of CFS patients where adequate diagnosis had been made and administered an extensive battery of measures. In doing so this study was able to replicate previous published evidence of clear cognitive impairment in this group and demonstrate also that these deficits occurred independent of psychopathology. The conclusion drawn is that cognitive impairments can be identified if appropriate measures are used. Furthermore, the authors have shown that performance changes in these measures have been used to assess both efficacy of a treatment regime and rates of recovery.

Chronic fatigue syndrome and DSM-IV personality disorders

OBJECTIVE

Personality is an important factor in the research of the chronic fatigue syndrome (CFS). Although some studies report a high rate of personality disorders--around the 40% level--in samples of patients with CFS, the generalizability of these findings can be questioned. The present study evaluates the prevalence of Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) personality disorders in a sample of female CFS patients and in two control groups.

METHOD

The ADP-IV questionnaire (Assessment of DSM Personality Disorders IV) was used to assess the DSM-IV-TR personality disorders at a dimensional and categorical level in a sample of 50 female CFS patients and in two matched control samples of Flemish civilians (n=50) and psychiatric patients (n=50).

RESULTS

The results indicate a striking lack of statistical significant differences between the CFS sample and the Flemish control group at the level of dimensional Trait scores, number of criteria, and prevalence rates of personality disorder diagnoses. Unsurprisingly, higher scores at these levels were obtained within the psychiatric sample. The prevalence of an Axis II disorder was 12% in the Flemish and CFS samples, whereas the psychiatric sample obtained a prevalence of 54%.

CONCLUSION

The prominent absence of any significant difference in personality disorder characteristics between the female Flemish general population and the CFS samples seems to suggest only a minor etiological role for personality pathology, as defined by the DSM-IV Axis II, within CFS.

Personality and chronic fatigue syndrome: Methodological and conceptual issues

Among clinical psychologists, consulting physicians, scientific researchers and society in general an image has emerged of patients with chronic fatigue syndrome (CFS) as perfectionist, conscientious, hardworking, somewhat neurotic and introverted individuals with high personal standards, a great desire to be socially accepted and with a history of continuously pushing themselves past their limits. The aim of this article is to (a) give a concise review of the main recent studies on personality and CFS, (b) address the major methodological problems in the study of personality in CFS and (c) discuss some of the conceptual assumptions that seem to limit the research on personality and CFS. The results of the reviewed studies range from no evidence of major differences between the personalities of patients with CFS and controls, to evidence of severe psychopathology and personality disorder in patients with CFS. Although personality seems to play a role in CFS, it is difficult to draw general conclusions on the relation between personality and CFS. It is argued that this is partially due to the diversity and heterogeneity in study methods, patient populations, control groups and CFS case definitions. Personality should be regarded as an important factor to be studied in CFS. However, additional studies are needed, not focusing exclusively on personality disorder, or personality considered on a general trait level. In recent developments in personality research, the continually evolving life narrative that makes sense of, and gives direction to, an individual's life is also regarded as an important aspect of personality. New insights into personality and CFS might be gained by systematically studying the self-narratives of patients with the syndrome.

Fatigue in liver disease: pathophysiology and clinical management

Fatigue is the most commonly encountered symptom in patients with liver disease, and it has a significant impact on their quality of life. However, although some progress has been made with regard to the understanding of the processes which may generate fatigue in general, the underlying cause(s) of liver disease-associated fatigue remain incompletely understood. The present review describes recent advances which have been made in our ability to measure fatigue in patients with liver disease in the clinical setting, as well as in our understanding of potential pathways which are likely important in the pathogenesis of fatigue associated with liver disease. Specifically, experimental findings suggest that fatigue associated with liver disease likely occurs as a result of changes in neurotransmission within the brain. In conclusion, a reasonable approach to help guide in the management of the fatigued patient with liver disease is presented.

Alcohol use in chronic fatigue syndrome

OBJECTIVE

To examine the anecdotal observation that patients with chronic fatigue syndrome develop alcohol intolerance.

METHODS

A consecutive case series of 114 patients fulfilling UK criteria for chronic fatigue syndrome referred to a specialist clinic. Self-reported alcohol use pre- and postdiagnosis, fatigue symptoms and comorbidity measures were collected.

RESULTS

Two-thirds reduced alcohol intake. The most common reasons were increased tiredness after drinking (67%), increased nausea (33%), exacerbated hangovers (23%) and sleep disturbance (24%). One-third of the subjects also stopped drinking because "it seemed sensible." Some had been advised to avoid alcohol, but the majority (66%) did so on the basis of personal experience.

CONCLUSION

Our data supports the anecdotal belief that chronic fatigue syndrome patients reduce or cease alcohol intake. This is associated with greater impairment in employment, leisure and social domains of function, and may hint at psycho-pathophysiological processes in common with other conditions that result in alcohol intolerance.

Perception of cognitive performance in patients with chronic fatigue syndrome

This study examined discrepancies between perceived and actual performance by patients with chronic fatigue syndrome (CFS) confronted with a challenging cognitive task. Before and after completing a modified version of the Stroop task, 40 patients and 40 healthy control participants estimated their own performance and the performance that would normally be achieved by someone of equal age and education level. After correcting for differences between the groups in depression, we found no differences in actual performance on the Stroop. However, patients with CFS consistently underestimated their performance relative to normal performance. This difference was observed for both depressed and nondepressed subgroups of patients, persisted after adjusting the results for depression, and correlated with patients' ratings of the mental effort and fatigue evoked by the task. The results are discussed in light of cognitive models of CFS that suggest the setting of impossibly high standards of personal performance may contribute to the dynamism of this disease.

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.

Clinical Dimensions of Fatigue

Because the symptom of fatigue is often vague, clinical evaluation requires the consideration of distinct features such as timing, precipitants, presence of libido, sleep quality, exercise capacity, and sedation. Fatigue has dimensions of affect and tolerability. In chronic illness, it is helpful to consider mood, physical conditioning, course of predictable treatment consequences, postural hypotension, and the well-being of caretakers. The differential diagnosis of acute and chronic fatigue is considered. Chronic fatigue of unknown etiology is placed in historical context, and an approach to the complexities of providing continuing evaluation and care is discussed.

Premorbid "overactive" lifestyle in chronic fatigue syndrome and fibromyalgia. An etiological factor or proof of good citizenship?

OBJECTIVE

In a former study, we have shown that patients suffering from chronic fatigue syndrome (CFS) or chronic pain, when questioned about their premorbid lifestyle, reported a high level of "action-proneness" as compared to control groups. The aim of the present study was to control for the patients' possible idealisation of their previous attitude towards action.

METHODS

A validated Dutch self-report questionnaire measuring "action-proneness" (the HAB) was completed by 62 randomly selected tertiary care CFS and fibromyalgia (FM) patients, as well as by their significant others (SOs).

RESULTS

HAB scores of the patients and those of the SOs were very similar and significantly higher than the norm values. Whether or not the SO showed sympathy for the patient's illness did not influence the results to a great extent. SOs with a negative attitude towards the illness even characterized the patients as more "action-prone."

CONCLUSIONS

These results provide further support for the hypothesis that a high level of "action-proneness" may play a predisposing, initiating and/or perpetuating role in CFS and FM.

Coping and adaptive outcome in chronic fatigue syndrome: importance of illness cognitions

In this study, the relations between illness representations, coping behavior, and adaptive outcomes in chronic fatigue syndrome (CFS) patients (N=98) were examined. Following Leventhal's self-regulation model, it was hypothesized that illness representations would be directly related to coping and, via coping, to adaptive outcome. The results showed patients who considered their illness to be a serious condition, who believed that they had no control over their illness, who saw little possibility for cure, and who believed their illness to have serious consequences to cope with their illness in a passive way, report higher levels of impairment in physical and social functioning and report greater problems in mental health and vitality. A series of regression analyses showed illness representations to be stronger predictors of adaptive outcome than coping scores. The implications of these findings for the treatment of CFS patients are discussed.

Poor concentration and the ability to process information after glandular fever

The symptom of poor concentration and the ability to process information were measured prospectively in 245 subjects three times in the 6 months after glandular fever or an ordinary upper respiratory tract infection. The effects of the different infections, having a fatigue state, a psychiatric disorder, sleep disturbance, and estimates of premorbid intelligence were also assessed. The most frequent complaint of poor concentration and the worst information processing occurred at the onset of the infection, but these problems decreased over time, and were not related to each other. Multiple regression modeling showed that higher socioeconomic class and vocabulary IQ were associated with information processing ability at all three interviews. In contrast, logistic regression modeling showed that the symptom of poor concentration was associated with the severity of general psychiatric morbidity (CIS score) followed by suffering from a fatigue state. These results suggest that the ability to process information after these particular infections is related to estimates of premorbid IQ, whereas poor concentration is related independently to both psychiatric morbidity and a fatigue state, but not the particular infection itself.