Atypical depression as a secondary symptom in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) has gained prominence since 1988 and a substantial amount of research has been done in this domain. However, it is still regarded as a controversial condition. Moreover, most of the symptoms of CFS itself are non-specific, occurring in many illnesses; some of the symptoms are also common in depression. Indeed, an area of continued controversy and debate involves the diagnostic overlap between CFS and psychiatric disorders. Through anecdotal evidence, atypical depression appears to be common in CFS. Recent developments in psychobiology underscore the role of the acute phase response and its associated sickness behavior in affective disorders. Thus, we hypothesize that atypical depression is sickness behavior rather than an affective disorder as shown by anecdotal evidence in CFS.

 

Source: Van Hoof E, Cluydts R, De Meirleir K. Atypical depression as a secondary symptom in chronic fatigue syndrome. Med Hypotheses. 2003 Jul;61(1):52-5. http://www.ncbi.nlm.nih.gov/pubmed/12781640

 

Chronic fatigue and organophosphate pesticides in sheep farming: a retrospective study amongst people reporting to a UK pharmacovigilance scheme

Abstract:

The Department of Health has recently published a report from the CFS/ME Working Group which concluded that chronic fatigue syndrome (CFS) should be recognized as a chronic illness. Symptoms consistent with CFS are often reported by people who consider their health has been affected by exposure to pesticides, but the Working Group concluded that this type of exposure is not a common trigger for the syndrome.

The Veterinary Medicines Directorate (VMD) collects self-assessed reports of ill health in humans associated with veterinary medicines under their Suspected Adverse Reaction Surveillance Scheme. The reporters have mainly been sheep farmers. These reports were used to investigate the possible relationship between chronic fatigue (CF) and exposure to organophosphate pesticides in sheep farming. The overall aim of the study was to investigate a possible association between exposure to organophosphates and the development of CF amongst people who consider their health has been affected by pesticides in sheep farming. The hypothesis investigated was that repeated exposure to organophosphate pesticides in sheep dip may increase the probability of developing CF. A group of mostly sheep farmers who had reported to the VMD surveillance scheme were identified.

We planned to use a retrospective case-control study design but the initial symptoms reports were not sufficiently reliable to enable this. The study population was asked to complete two questionnaires. The first questionnaire was designed to identify the history of exposure of subjects to organophosphate pesticides, and their exposure was then reconstructed using a metric specifically developed for this purpose. The second questionnaire collected detailed information to identify whether the subjects had CF when they originally reported to the VMD and at the time of the survey.

The questionnaire was sent to a total of 206 subjects, of whom 28 had moved home. A total of 37% of the remaining 178 subjects participated. There was a high prevalence of CF amongst those who completed the questionnaire and this has generally persisted since the subjects reported to the VMD. Higher CF scores were associated with higher exposure to organophosphate pesticides.

CF is very common amongst those who consider their health was affected by pesticides and we have shown there is limited evidence of an association between exposure to organophosphates and CF. Further research is needed to investigate the cause of this syndrome amongst farmers exposed to pesticides.

 

Source: Tahmaz N, Soutar A, Cherrie JW. Chronic fatigue and organophosphate pesticides in sheep farming: a retrospective study amongst people reporting to a UK pharmacovigilance scheme. Ann Occup Hyg. 2003 Jun;47(4):261-7. http://annhyg.oxfordjournals.org/content/47/4/261.long (Full article)

 

Examining the influence of biological and psychological factors on cognitive performance in chronic fatigue syndrome: a randomized, double-blind, placebo-controlled, crossover study

Abstract:

The pathophysiology of chronic fatigue syndrome (CFS) remains unclear; however, both biological and psychological factors have been implicated in establishing or maintaining this condition. People with CFS report significant and disabling cognitive difficulties such as impaired concentration that in some cases are exacerbated by exposure to chemical triggers. The aim of this study was to determine if neuropsychological deficits in CFS are triggered by exposure to chemicals, or perceptions about the properties of these substances.

Participants were 36 people with a primary diagnosis of CFS, defined according to Centers for Disease Control (CDC) criteria. A randomized, double-blind, placebo-controlled, crossover design was used, with objective assessment of neuropsychological function and participant rating of substance type, before and after exposure to placebo or chemical trigger. Results showed decrements in neuropsychological tests scores on three out of four outcome measures when participants rated the substance they had been exposed to as “chemical.” No change in performance was found based on actual substance type.

These results suggest that cognitive attributions about exposure substances in people with CFS may be associated with worse performance on neuropsychological tasks. In addition, these findings suggest that psychological interventions aimed at modifying substance-related cognitions may reduce some symptoms of CFS.

 

Source: Smith S, Sullivan K. Examining the influence of biological and psychological factors on cognitive performance in chronic fatigue syndrome: a randomized, double-blind, placebo-controlled, crossover study. Int J Behav Med. 2003;10(2):162-73. http://www.ncbi.nlm.nih.gov/pubmed/12763708

 

Comparison of subjective and objective measures of insomnia in monozygotic twins discordant for chronic fatigue syndrome

Abstract:

STUDY OBJECTIVES: To examine the objective and subjective measures of insomnia in chronic fatigue syndrome (CFS).

DESIGN: Monozygotic co-twin control study.

SETTING: Academic medical center.

PATIENTS OR PARTICIPANTS: Twenty-two pairs of monozygotic twins where 1 member of the pair had CFS and the other did not.

INTERVENTIONS: N/A.

MEASUREMENTS AND RESULTS: Twenty-two CFS-discordant twin pairs completed a Sleep Disorders Questionnaire, overnight polysomnography, and a postpolysomnography sleep survey. Mean and percent differences in the sleep measures were compared between the CFS and healthy twins using matched-pair methods of analysis. Compared with their healthy co-twins, the CFS twins more frequently endorsed 8 subjective measures of insomnia and poor sleep (all p < or = 0.05). However, the CFS and healthy twins did not differ in objective polysomnographic measures of insomnia, including sleep latency, total sleep time, sleep efficiency, arousal number, arousal index, hypnogram awakenings, rapid eye movement (REM)-sleep latency, and percent stages 1, 2, and 3-4 (delta). Percent stage REM sleep was increased in the CFS twins compared with the healthy twins (27.7% vs. 24.4%, p < or = 0.05). On the postpolysomnography survey, CFS twins reported that they had slept fewer hours (6.2 vs. 6.7; p < or = 0.05), and were less well rested (p < or = 0.001) compared to their co-twins.

CONCLUSIONS: CFS patients had worse subjective sleep than their co-twins despite little objective data supporting this discrepancy, suggesting they suffer from an element of sleep-state misperception. The higher percentage of REM sleep in the CFS twins implies that REM sleep may play a role in this illness.

 

Source: Watson NF, Kapur V, Arguelles LM, Goldberg J, Schmidt DF, Armitage R, Buchwald D. Comparison of subjective and objective measures of insomnia in monozygotic twins discordant for chronic fatigue syndrome. Sleep. 2003 May 1;26(3):324-8. http://www.ncbi.nlm.nih.gov/pubmed/12749553

 

Hypothalamic digoxin, cerebral chemical dominance and myalgic encephalomyelitis

Abstract:

The isoprenoid pathway was assessed in 15 patients with chronic fatigue syndrome. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance had any correlation with these disease states.

The isoprenoid metabolites–digoxin, dolichol, and ubiquinone–RBC membrane Na+-K+ ATPase activity, serum magnesium and tyrosine/tryptophan catabolic patterns were assessed. The free-radical metabolism, glycoconjugate metabolism, and RBC membrane composition was also assessed. Membrane Na+-K+ ATPase activity and serum magnesium levels were decreased while HMG CoA reductase activity and serum digoxin levels were increased in myalgic encephalomyelitis (ME). There were increased levels of tryptophan catabolites–nicotine, strychnine, quinolinic acid, and serotonin–and decreased levels of tyrosine catabolites–dopamine, noradrenaline, and morphine in ME. There was an increase in dolichol levels, carbohydrate residues of glycoproteins, glycolipids, total/individual GAG fractions, and lysosomal enzymes in ME. Reduced levels of ubiquinone, reduced glutathione, and free-radical scavenging enzymes, as well as increased lipid peroxidation products and nitric oxide, were noticed in ME.

The biochemical patterns in ME correlated with those obtained in right hemispheric chemical dominance. The role of hypothalamic digoxin and neurotransmitter induced immune activation, altered glycoconjugate metabolism, and resultant defective viral antigen presentation, NMDA excitotoxicity and cognitive dysfunction, and mitochondrial dysfunction related myalgia in the pathogenesis of ME is stressed. ME occurs in individuals with right hemispheric chemical dominance.

 

Source: Kurup RK, Kurup PA. Hypothalamic digoxin, cerebral chemical dominance and myalgic encephalomyelitis. Int J Neurosci. 2003 May;113(5):683-701. https://ammes.orgwp-admin/post-new.php

 

Clarifying the relationship between unexplained chronic fatigue and psychiatric morbidity: results from a community survey in Great Britain

Abstract:

The study examined the associations between several sociodemographic and psychosocial variables and unexplained chronic fatigue in the community before and after adjustment for psychiatric morbidity and determined the prevalence of fatigue and rate of disability resulting from fatigue in the general population. The study is a secondary analysis of 1993 data from a household survey of psychiatric morbidity conducted by the Office for Population Censuses and Surveys in Great Britain. The survey included 12,730 subjects age 16-64 years. Unexplained chronic fatigue was used as the dependent variable in a logistic regression analysis, with various sociodemographic and psychosocial variables and psychiatric morbidity as the independent variables. Psychiatric morbidity was assessed by using the Revised Clinical Interview Schedule. Fatigue was measured by using the fatigue section of the Revised Clinical Interview Schedule.

A total of 10,108 subjects agreed to cooperate (79.4% participation rate). The prevalence of unexplained chronic fatigue was 9%. Subjects with psychiatric morbidity had higher rates of fatigue. Adjustment for psychiatric morbidity had a minor effect on the associations between sociodemographic factors and chronic fatigue. After adjustment, older subjects, women, and couples with children had higher rates of fatigue. Single subjects, widowed subjects, adults living with parents, and economically inactive subjects had lower rates of fatigue. Fatigue was associated with considerable disability, but the association between fatigue and psychiatric morbidity explained most of this disability. Unexplained chronic fatigue is a common condition, strongly associated with psychiatric morbidity. The close relationship between fatigue and psychiatric morbidity should not obscure the possibility of differences as well as similarities in their aetiologies.

 

Source: Skapinakis P, Lewis G, Meltzer H. Clarifying the relationship between unexplained chronic fatigue and psychiatric morbidity: results from a community survey in Great Britain. Int Rev Psychiatry. 2003 Feb-May;15(1-2):57-64. http://www.ncbi.nlm.nih.gov/pubmed/12745311

 

Psychiatric morbidity in the chronic fatigue syndrome: are patients with personality disorder more physically impaired?

Abstract:

OBJECTIVE: The long-term consequences of chronic fatigue syndrome (CFS) include substantial impairment in physical functioning and high levels of work disability. In the absence of a medical explanation for this impairment, some have speculated that it may be due to comorbid psychiatric illness or personality disorder. We addressed this possibility by comparing the functional status of three CFS groups: no psychiatric diagnosis, psychiatric illness only, psychiatric illness and personality disorder. A second aim of the study was to determine whether a continuous measure of psychological distress could provide a better account of impairment than psychiatric diagnosis.

METHOD: The study sample consisted of 84 consecutive female referrals with CFS. All participants satisfied the case definition and completed an assessment protocol consisting of: physical examination, psychiatric interview and self-report questionnaires.

RESULTS: Psychiatric illness, either alone or in combination with a comorbid personality disorder, was not associated with physical impairment or disability in female participants. A regression model of physical functioning found that psychological distress accounted for 6% and symptom severity for 41% of the variance (P=.06 and <.01, respectively). In the case of disability, the corresponding percentages were 2% and 18% (NS and P<.01, respectively). The modest effects of psychological distress could not be attributed to symptom severity.

CONCLUSIONS: Although psychiatric illness and personality disorder was prevalent, neither could explain the effects of CFS on physical functioning and disability. As yet, there is no psychological or medical explanation for the behavioral consequences of CFS.

 

Source: Ciccone DS, Busichio K, Vickroy M, Natelson BH. Psychiatric morbidity in the chronic fatigue syndrome: are patients with personality disorder more physically impaired? J Psychosom Res. 2003 May;54(5):445-52. http://www.ncbi.nlm.nih.gov/pubmed/12726901

 

Childhood experiences of illness and parenting in adults with chronic fatigue syndrome

Abstract:

OBJECTIVE: There are many similarities between chronic fatigue syndrome (CFS), the somatoform disorders and problems otherwise known as “medically unexplained symptoms.” There is some evidence to suggest that a combination of inadequate parenting and early illness experience may predispose the individual to develop medically unexplained symptoms in adult life. The aim of this investigation was to compare the contributions of childhood experiences of illness and parenting in adults with CFS with a fracture clinic control group.

METHOD: A retrospective case control design was used. Thirty patients with a diagnosis of CFS and 30 patients attending a fracture clinic in an inner London teaching hospital completed questionnaires measuring parental care and protection and were interviewed about childhood experiences of illness.

RESULTS: There were no differences in childhood experience of illness in the two groups. However, logistic regression revealed that maternal overprotection and depression were associated with the diagnosis of CFS.

CONCLUSION: The findings may represent risk factors for the development of CFS in adult life. It is possible that maternal overprotection in particular is related to the formation of belief systems about avoiding activity that operate to adversely influence behaviour in patients with CFS.

 

Source: Fisher L, Chalder T. Childhood experiences of illness and parenting in adults with chronic fatigue syndrome. J Psychosom Res. 2003 May;54(5):439-43. http://www.ncbi.nlm.nih.gov/pubmed/12726900

 

Review: cognitive behavioural interventions may be effective for chronic fatigue syndrome and chronic back pain

Comment on: Systematic review of mental health interventions for patients with common somatic symptoms: can research evidence from secondary care be extrapolated to primary care? [BMJ. 2002]

 

Psychological disorders have a high financial burden with many indirect costs. Behavioural strategies and cognitive behavioural interventions may be effective for a range of mental disorders, including some of the most chronic, severe and costly mental health problems.1 Very few medical professionals are adequately trained to deliver such treatments, however. This article is both timely and important because it emphasises the need to disseminate cognitive behaviour therapies more widely.

Raine et al conducted a thorough review of the efficacy of psychological treatments for common somatic symptoms: chronic fatigue syndrome, irritable bowel syndrome and chronic back pain. The results were consistent with the findings by the American Psychological Association’s Task Force on Promotion and Dissemination of Psychological Procedures:2 cognitive behaviour interventions and behaviour therapy are effective for treating chronic back pain and chronic fatigue syndrome. Raine et al found that treatment effects were stronger in secondary care compared with primary care settings. Furthermore, antidepressants were effective in both settings for treating irritable bowel syndrome.

The review has some limitations. First, as in all secondary analyses, the review is based only on published studies (that are more likely to report positive outcomes). There may also be problems with how interventions were defined and implemented. The majority of studies did not follow a treatment manual and did not measure adherence to the therapy protocol. The distinction between “behaviour therapy” and “cognitive-behaviour therapy” therefore remains elusive. This leaves important questions unanswered about how and why these treatments work (ie the mechanisms and mediators of change).3

You can read the rest of this comment here: http://ebmh.bmj.com/content/6/2/55.long

 

Source: Hofmann SG. Review: cognitive behavioural interventions may be effective for chronic fatigue syndrome and chronic back pain. Evid Based Ment Health. 2003 May;6(2):55. http://ebmh.bmj.com/content/6/2/55.long (Full article)

 

Psychometric properties of the Dutch Chronic Fatigue Syndrome–Activities and Participation Questionnaire (CFS-APQ)

Abstract:

BACKGROUND AND PURPOSE: The Chronic Fatigue Syndrome-Activities and Participation Questionnaire (CFS-APQ) is a recently developed disease-specific assessment tool for monitoring activity limitations and participation restrictions in patients with chronic fatigue syndrome (CFS). In this study, the convergent validity, content validity, and test-retest reliability of data obtained with the Dutch-language version of the questionnaire were examined.

SUBJECTS AND METHODS: One hundred eleven consecutive patients with CFS were enrolled, of whom 47 fulfilled all inclusion criteria. The subjects were first asked to rate their pain, fatigue, and ability to concentrate using 3 visual analog scales, to list at least 5 activities that had become difficult to perform due to their complaints, and to complete the CFS-APQ. Furthermore, subjects were asked to complete a modified version of the CFS-APQ at home and return it to the investigators. The content of the questionnaire was reviewed using the World Health Organization’s International Classification of Impairments, Disability and Health (ICIDH) beta II draft. Spearman rank correlation coefficients (R) were used for the convergent validity analysis, and intraclass correlation coefficients were computed for the assessment of the test-retest data.

RESULTS: Overall scores on the CFS-APQ correlated with the scores from the visual analog scales for pain (R=.51, P<.001) and fatigue (R=.50, P<.001). The majority of the responses (157 out of 183 answers [85.8%]) to the request to “list difficult activities” matched the content of the CFS-APQ. Using the ICIDH beta II draft, 21 out of 26 questions were found to address activities, and the remaining 5 questions measured the participation level. The Cronbach alpha coefficient was.94, and intraclass correlation coefficients for test-retest reliability of the overall scores were >or= .95 (P<.001).

DISCUSSION AND CONCLUSION: The results substantiate the convergent validity, content validity, and reliability of the CFS-APQ scores for patients with CFS.

 

Source: Nijs J, Vaes P, McGregor N, Van Hoof E, De Meirleir K. Psychometric properties of the Dutch Chronic Fatigue Syndrome–Activities and Participation Questionnaire (CFS-APQ). Phys Ther. 2003 May;83(5):444-54. http://ptjournal.apta.org/content/83/5/444.long (Full article)