Comorbid illness in women with chronic fatigue syndrome: a test of the single syndrome hypothesis

Abstract:

OBJECTIVE: Evidence of comorbidity among unexplained illness syndromes raises the possibility that all are variants of a single functional disorder, leading some to suggest that separate case definitions for chronic fatigue syndrome (CFS), fibromyalgia (FM), and multiple chemical sensitivity (MCS) may be unnecessary. Our objective was to determine whether discrete diagnostic labels provide useful information about physical functioning, symptom severity, and risk of psychiatric illness.

METHODS: The sample consisted of 163 consecutive female referrals with CFS enrolled at a tertiary clinic. Each participant was retrospectively assigned to one of four groups: CFS only, CFS/FM, CFS/MCS, and CFS/FM/MCS. At enrollment, participants gave their history, underwent a physical examination and a standardized psychiatric interview (Diagnostic Interview Schedule), and answered self-report questionnaires.

RESULTS: Additional unexplained syndromes were prevalent: 37% met criteria for FM, and 33% met criteria for MCS. With the exception of FM-related pain and disability, there were few differences between the CFS only and CFS with comorbid illness groups. Patients with additional illness were more likely to have major depression and a higher risk of psychiatric morbidity compared with patients in the CFS only group (p <.01). Rates of lifetime depression increased from 27.4% in the CFS only group to 52.3% in the CFS/FM group, 45.2% in the CFS/MCS group, and 69.2% in the CFS/FM/MCS group.

CONCLUSIONS: The prevalence of comorbid illness in the present CFS sample and the failure to find widespread differences in symptom severity can be seen as support for the single syndrome hypothesis. On the other hand, the existence of discrete syndromes could not be ruled out because of reliable differences between CFS and CFS/FM. Increasing comorbidity was associated with a corresponding increase in risk of major depression.

 

Source: Ciccone DS, Natelson BH. Comorbid illness in women with chronic fatigue syndrome: a test of the single syndrome hypothesis. Psychosom Med. 2003 Mar-Apr;65(2):268-75. http://www.ncbi.nlm.nih.gov/pubmed/12651994

 

 

Psychiatric adjustment in chronic fatigue syndrome of childhood and in juvenile idiopathic arthritis

Abstract:

BACKGROUND: High rates of psychopathology and of personality problems have been reported in children and adolescents with chronic fatigue syndrome (CFS). It is not clear whether this is consequent on the experience of chronic physical ill health. We compare psychiatric adjustment in children with CFS and in children suffering from another chronic physical disorder (juvenile idiopathic arthritis or JIA).

METHOD: Our sample consisted of 28 children with CFS and 30 with JIA attending tertiary paediatric centres (age range, 11 to 18 years, mean 15, S.D. 2.3). In order to assess psychiatric status and functioning, we used the K-SADS psychiatric interviews, CGAS and Harter Self-Esteem Questionnaire with child subjects; behavioural questionnaires (CBCL) and child personality assessment interviews (PAS) with parent informants.

RESULTS: Psychiatric disorders in the year prior to interview had been present significantly more commonly in the CFS group (72% v. 34% in JIA) and were more impairing to them (CGAS scores of 45 v. 77). Most common diagnoses in both groups were depressive and anxiety disorders. Personality problems were also significantly more frequent in CFS subjects (48% disorder and 26% difficulty v. 11% and 11% in JIA). There were few differences between the two groups in self-esteem.

CONCLUSIONS: Psychopathology and personality problems are common in children and adolescents with severe forms of CFS and cannot be explained strictly through the experience of chronic physical illness.

Comment in: Costs, correlates and consequences of fatigue in children and adults. [Psychol Med. 2003]

 

Source: Rangel L, Garralda ME, Hall A, Woodham S. Psychiatric adjustment in chronic fatigue syndrome of childhood and in juvenile idiopathic arthritis. Psychol Med. 2003 Feb;33(2):289-97. http://www.ncbi.nlm.nih.gov/pubmed/12622307

 

Psychological correlates of functional status in chronic fatigue syndrome

Abstract:

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.

 

Source: Taillefer SS, Kirmayer LJ, Robbins JM, Lasry JC. Psychological correlates of functional status in chronic fatigue syndrome. J Psychosom Res. 2002 Dec;53(6):1097-106. http://www.ncbi.nlm.nih.gov/pubmed/12479992

 

Peripheral blood mononuclear cell beta-endorphin concentration is decreased in chronic fatigue syndrome and fibromyalgia but not in depression: preliminary report

Abstract:

OBJECTIVE: The aim of this study was to examine the possible role of the immune system in the pathophysiology of chronic fatigue syndrome and fibromyalgia syndrome and in the differential diagnosis of depression by investigating changes in peripheral blood mononuclear cell levels of beta-endorphin, an endogenous opioid known to be involved in regulation of the immune system function.

DESIGN: Beta-endorphin concentrations were measured by radioimmunoassay in peripheral blood mononuclear cells from healthy controls (n = 8) and patients with chronic fatigue syndrome (n = 17), fibromyalgia syndrome (n = 5), or depression (n = 10).

RESULTS: Beta-endorphin concentrations were significantly lower in patients with chronic fatigue syndrome or fibromyalgia syndrome than in normal subjects and depressed patients (p <0.001 and p <0.01, respectively). They were significantly higher in depressed patients than in controls (p <0.01).

CONCLUSIONS: Evaluation of peripheral blood mononuclear cell beta-endorphin concentrations could represent a diagnostic tool for chronic fatigue syndrome and fibromyalgia and help with differential diagnosis of these syndromes versus depression. The results obtained are also consistent with the hypothesis that the immune system is activated in both chronic fatigue syndrome and fibromyalgia syndrome.

 

Source: Panerai AE, Vecchiet J, Panzeri P, Meroni P, Scarone S, Pizzigallo E, Giamberardino MA, Sacerdote P. Peripheral blood mononuclear cell beta-endorphin concentration is decreased in chronic fatigue syndrome and fibromyalgia but not in depression: preliminary report. Clin J Pain. 2002 Jul-Aug;18(4):270-3. http://www.ncbi.nlm.nih.gov/pubmed/12131069

 

Cognitive functioning in chronic fatigue syndrome and the role of depression, anxiety, and fatigue

Abstract:

OBJECTIVE: This study was designed to investigate the role of depression, anxiety, and fatigue in Chronic Fatigue Syndrome (CFS) sufferers’ objective and subjective cognitive performance.

METHODS: Twenty-three CFS sufferers and 23 healthy control participants were compared on objective and subjective assessments of cognitive performance. Depression, anxiety, and fatigue were also evaluated.

RESULTS: CFS sufferers did not demonstrate any impairment in objective cognitive functioning compared to the control group, and objective performance was not related to their higher levels of depression or their level of fatigue. Depression scores only accounted for a small amount of the variance in CFS sufferers’ lower subjective assessment of their cognitive performance compared to control participants. There were no differences between the groups on anxiety scores.

CONCLUSION: The results are discussed in terms of the heterogeneity of the CFS population and the complex interaction of symptomatological factors that characterise CFS.

 

Source: Short K, McCabe M, Tooley G. Cognitive functioning in chronic fatigue syndrome and the role of depression, anxiety, and fatigue. J Psychosom Res. 2002 Jun;52(6):475-83. http://www.ncbi.nlm.nih.gov/pubmed/12069872

 

Illness experience, depression, and anxiety in chronic fatigue syndrome

Abstract:

OBJECTIVE: Given the high rate of psychiatric comorbidity with chronic fatigue syndrome (CFS), we considered two possible correlates of anxiety and depression: lack of illness legitimization and beliefs about limiting physical activity.

METHOD: A total of 105 people diagnosed with CFS reported on their experiences with medical professionals and their beliefs about recovery and completed the depression and anxiety subscales of the Brief Symptom Inventory.

RESULTS: Those who said that their physician did not legitimize their illness (36%) had higher depression and anxiety scores (P’s<.05) than their counterparts. Those who believed that limiting their physical exertion was the path to recovery (55%) had lower depression and anxiety scores (P’s<.01) than their counterparts.

CONCLUSION: Lack of illness legitimization ranked high as a source of dissatisfaction for CFS patients, and it may aggravate psychiatric morbidity. Many CFS patients believed that staying within what they felt to be their physical limits would improve their condition. This belief, and possibly an accompanying sense of control over their symptoms, may alleviate psychiatric morbidity.

 

Source: Lehman AM, Lehman DR, Hemphill KJ, Mandel DR, Cooper LM. Illness experience, depression, and anxiety in chronic fatigue syndrome. J Psychosom Res. 2002 Jun;52(6):461-5. http://www.ncbi.nlm.nih.gov/pubmed/12069870

 

The genetic aetiology of somatic distress

Abstract:

BACKGROUND: Somatoform disorders such as neurasthenia and chronic fatigue syndrome are characterized by a combination of prolonged mental and physical fatigue. This study aimed to investigate the heritability of somatic distress and determine whether this dimension is aetiologically distinct from measures of depression and anxiety.

METHOD: Measures of anxiety, depression, phobic anxiety, somatic distress and sleep difficulty were administered in a self-report questionnaire to a community-based sample of 3469 Australian twin individuals aged 18 to 28 years. Factor analysis using a Promax rotation, produced four factors: depression, phobic anxiety, somatic distress and sleep disturbance. Multivariate and univariate genetic analyses of the raw categorical data scores for depression, phobic anxiety and depression were then analysed in Mx1.47.

RESULTS: Univariate genetic analysis revealed that an additive genetic and non-shared environmental (AE) model best explained individual differences in depression and phobic anxiety scores, for male and female twins alike, but could not resolve whether additive genes or shared environment were responsible for significant familial aggregation in somatic distress. However, multivariate genetic analysis showed that an additive genetic and non-shared environment (AE) model best explained the covariation between the three factors. Furthermore, 33 % of the genetic variance in somatic distress was due to specific gene action unrelated to depression or phobic anxiety. In addition, 74% of the individual environmental influence on somatic distress was also unrelated to depression or phobic anxiety.

CONCLUSION: These results support previous findings that somatic symptoms are relatively aetiologically distinct both genetically and environmentally from symptoms of anxiety and depression.

 

Source: Gillespie NA, Zhu G, Heath AC, Hickie IB, Martin NG. The genetic aetiology of somatic distress. Psychol Med. 2000 Sep;30(5):1051-61. http://www.ncbi.nlm.nih.gov/pubmed/12027042

 

Symptom occurrence in persons with chronic fatigue syndrome

Abstract:

This investigation compared differences in the occurrence of symptoms in participants with CFS, melancholic depression, and no fatigue (controls). The following Fukuda et al. [Ann. Intern. Med. 121 (1994) 953] criteria symptoms differentiated the CFS group from controls, but did not differentiate the melancholic depression group from controls: headaches, lymph node pain, sore throat, joint pain, and muscle pain. In addition, participants with CFS uniquely differed from controls in the occurrence of muscle weakness at multiple sites as well as in the occurrence of various cardiopulmonary, neurological, and other symptoms not currently included in the current case definition. Implications of these findings are discussed.

 

Source: Jason LA, Torres-Harding SR, Carrico AW, Taylor RR. Symptom occurrence in persons with chronic fatigue syndrome. Biol Psychol. 2002 Feb;59(1):15-27. http://www.ncbi.nlm.nih.gov/pubmed/11790441

 

Chronic fatigue and anxiety/depression: a twin study

Abstract:

BACKGROUND: Up to three-quarters of patients with fatigue syndromes have comorbid mood or anxiety disorders, suggesting that chronic fatigue is a forme fruste of anxiety or depressive states.

AIMS: To establish whether the association of chronic fatigue with psychological distress is causal or due to a common genetic or environmental factor.

METHOD: 69 monozygotic (MZ) and 31 dizygotic (DZ) female twin pairs, with only one co-twin reporting at least 6 months of fatigue, completed questions on fatigue, the General Health Questionnaire (GHQ) and a structured psychiatric interview. We examined the effects of three progressively more stringent definitions of chronic fatigue on four GHQ sub-scales.

RESULTS: Fatigued MZ and DZ twins by all definitions were significantly more depressed, anxious, somatically preoccupied and socially dysfunctional than their non-fatigued co-twins. Intrapair differences were similar in DZ and MZ twins, but non-significant differences were observed for the somatic symptoms and anxiety/insomnia sub-scales.

CONCLUSIONS: In this sample, chronic fatigue and psychological distress are strongly associated without evidence for genetic covariation, implying that the association is environmental, or due to overlapping definitions. Any genetic covariation missed is likely to involve anxiety rather than depression.

 

Source: Roy-Byrne P, Afari N, Ashton S, Fischer M, Goldberg J, Buchwald D. Chronic fatigue and anxiety/depression: a twin study. Br J Psychiatry. 2002 Jan;180:29-34. http://www.ncbi.nlm.nih.gov/pubmed/11772848

 

Interpretation of symptoms in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is an illness characterised by fatigue and other symptoms. Both psychological and biological aetiological factors have been proposed, but the disorder is of uncertain origin. The aetiology of the symptoms is therefore ambiguous. It has been suggested (a) that patients with CFS tend to interpret their symptoms as indicating physical illness and (b) they tend not to interpret these symptoms in terms of negative emotion.

In order to test these hypotheses we developed a self-report questionnaire to assess the interpretation of symptoms in patients with CFS. It was administered to patients with CFS, patients with depression, patients with multiple sclerosis (MS), and normal controls. Preliminary results suggest that the measure has acceptable psychometric properties.

Patients with CFS were more likely than either depressed patients or normal controls to interpret symptoms (characteristic of CFS) in terms of physical illness, but did not differ in this from the MS patients. When compared with all three other groups (including the MS patients), the patients with CFS were least likely to interpret symptoms in terms of negative emotional states. The theoretical and clinical implications of the findings are discussed.

 

Source: Dendy C, Cooper M, Sharpe M. Interpretation of symptoms in chronic fatigue syndrome. Behav Res Ther. 2001 Nov;39(11):1369-80. http://www.ncbi.nlm.nih.gov/pubmed/11686271