Afari – American ME and CFS Society

The comorbidity of self-reported chronic fatigue syndrome, post-traumatic stress disorder, and traumatic symptoms

Abstract:

BACKGROUND: Data from primary care and community samples suggest higher rates of post-traumatic stress disorder (PTSD) among individuals with chronic fatigue syndrome (CFS).

OBJECTIVE: This study investigated the co-occurrence of CFS, PTSD, and trauma symptoms and assessed the contribution of familial factors to the association of CFS with lifetime PTSD and current traumatic symptoms.

METHOD: Data on lifetime CFS and PTSD, as measured by self-report of a doctor’s diagnosis of the disorder, and standardized questionnaire data on traumatic symptoms, using the Impact of Events Scale (IES), were obtained from 8544 female and male twins from the community-based University of Washington Twin Registry.

RESULTS: Lifetime prevalence of CFS was 2% and lifetime prevalence of PTSD was 4%. Participants who reported a history of PTSD were over eight times more likely to report a history of CFS. Participants with scores ≥ 26 on the IES were over four times more likely to report CFS than those who had scores ≤ 25. These associations were attenuated but remained significant after adjusting for familial factors through within-twin pair analyses.

CONCLUSION: These results support similar findings that a lifetime diagnosis of CFS is strongly associated with both lifetime PTSD and current traumatic symptoms, although familial factors, such as shared genetic and environmental contributions, played a limited role in the relationship between CFS, PTSD, and traumatic symptoms. These findings suggest that future research should investigate both the familial and the unique environmental factors that may give rise to both CFS and PTSD.

Published by Elsevier Inc.

Source: Dansie EJ, Heppner P, Furberg H, Goldberg J, Buchwald D, Afari N. The comorbidity of self-reported chronic fatigue syndrome, post-traumatic stress disorder, and traumatic symptoms. Psychosomatics. 2012 May-Jun;53(3):250-7. doi: 10.1016/j.psym.2011.08.007. Epub 2012 Jan 31. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3343192/ (Full article)

Conditions comorbid with chronic fatigue in a population-based sample

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) has been found to be comorbid with various medical conditions in clinical samples, but little research has investigated CFS comorbidity in population-based samples.

OBJECTIVE: This study investigated conditions concurrent with a CFS-like illness among twins in the population-based Mid-Atlantic Twin Registry (MATR), including chronic widespread pain (CWP), irritable bowel syndrome (IBS), and major depressive disorder (MDD).

METHOD: A survey was mailed to participants in the MATR in 1999. Generalized estimating equations were used to estimate odds ratios to assess associations between CFS-like illness and each comorbid condition.

RESULTS: A total of 4590 completed surveys were collected. Most participants were female (86.3%); mean age was 44.7 years. Among participants with a CFS-like illness, lifetime prevalences of CWP, IBS, and MDD were 41%, 16%, and 57% respectively. Participants reporting at least one of the three comorbid conditions were about 14 times more likely to have CFS-like illness than those without CWP, IBS, or MDD (95% confidence interval 8.1%-21.3%). Only MDD showed a temporal pattern of presentation during the same year as diagnosis of CFS-like illness. Age, gender, body mass index, age at illness onset, exercise level, self-reported health status, fatigue symptoms, and personality measures did not differ between those reporting CFS-like illness with and without comorbidity.

CONCLUSION: These results support findings in clinically based samples that CFS-like illness is frequently cormorbid with CWP, IBS, and/or MDD. We found no evidence that CFS-like illnesses with comorbidities are clinically distinct from those without comorbidities.

Source: Dansie EJ, Furberg H, Afari N, Buchwald D, Edwards K, Goldberg J, Schur E, Sullivan PF. Conditions comorbid with chronic fatigue in a population-based sample. Psychosomatics. 2012 Jan-Feb;53(1):44-50. doi: 10.1016/j.psym.2011.04.001. Epub 2011 Sep 22. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3254018/ (Full article)

Adolescent offspring of mothers with chronic fatigue syndrome

Abstract:

PURPOSE: The goal of this study was to determine whether adolescent offspring of mothers with chronic fatigue syndrome(CFS) have higher prevalence of CFS and report more fatigue, greater pain sensitivity, more sleep problems, and poorer cardiopulmonary fitness in comparison with offspring with no exposure to maternal CFS.

METHODS: A total of 26 adolescent offspring of 20 mothers diagnosed with CFS were compared with 45 adolescent offspring of 30 age-matched healthy control mothers. Study measures included structured interviews and medical and laboratory examinations for CFS; tender point examination; maximum oxygen uptake and perceived exertion; dolorimetry pain ratings; and questionnaires on fatigue severity and sleepiness.

RESULTS: In comparison with offspring of healthy mothers, those exposed to mothers with CFS reported higher prevalence of fatigue of at least 1-month duration (23% vs. 4%), fatigue of 6 months or longer (15% vs. 2%), and met criteria for CFS (12% vs. 2%), although these differences only approached statistical significance. CFS and healthy mothers differed on almost all study outcomes, but offspring groups did not differ on measures of current fatigue severity, pain sensitivity, sleep, mean number of tender points, and cardiopulmonary fitness.

CONCLUSIONS: The higher prevalence of fatiguing states in offspring of CFS mothers, despite the lack of statistical significance, suggests that familial factors may potentially play a role in developing chronically fatiguing states. Alternately, perturbations in pain sensitivity and cardiopulmonary fitness may be consequences of CFS. Future studies should focus on examining the impact of maternal CFS and associated disability on psychosocial functioning of offspring.

Source: Smith MS, Buchwald DS, Bogart A, Goldberg J, Smith WR, Afari N. Adolescent offspring of mothers with chronic fatigue syndrome. J Adolesc Health. 2010 Mar;46(3):284-91. doi: 10.1016/j.jadohealth.2009.08.001. Epub 2009 Oct 13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824612/ (Full article)

Twin analyses of fatigue

Abstract:

Prolonged fatigue equal to or greater than 1 month duration and chronic fatigue equal to or greater than 6 months duration are both commonly seen in clinical practice, yet little is known about the etiology or epidemiology of either symptom. Chronic fatigue syndrome (CFS), while rarer, presents similar challenges in determining cause and epidemiology. Twin studies can be useful in elucidating genetic and environmental influences on fatigue and CFS. The goal of this article was to use biometrical structural equation twin modeling to examine genetic and environmental influences on fatigue, and to investigate whether these influences varied by gender. A total of 1042 monozygotic (MZ) twin pairs and 828 dizygotic (DZ) twin pairs who had completed the University of Washington Twin Registry survey were assessed for three fatigue-related variables: prolonged fatigue, chronic fatigue, and CFS. Structural equation twin modeling was used to determine the relative contributions of additive genetic effects, shared environmental effects, and individual-specific environmental effects to the 3 fatigue conditions. In women, tetrachoric correlations were similar for MZ and DZ pairs for prolonged and chronic fatigue, but not for CFS. In men, however, the correlations for prolonged and chronic fatigue were higher in MZ pairs than in DZ pairs. About half the variance for both prolonged and chronic fatigue in males was due to genetic effects, and half due to individual-specific environmental effects. For females, most variance was due to individual environmental effects.

Source: Schur E, Afari N, Goldberg J, Buchwald D, Sullivan PF. Twin analyses of fatigue. Twin Res Hum Genet. 2007 Oct;10(5):729-33. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953372/ (Full article)

Post-traumatic stress disorder among patients with chronic pain and chronic fatigue

Abstract:

BACKGROUND: Fibromyalgia (FM), a chronic pain condition of unknown aetiology often develops following a traumatic event. FM has been associated with post-traumatic stress disorder (PTSD) and major depression disorder (MDD).

METHOD: Patients seen in a referral clinic (N=571) were evaluated for FM and chronic fatigue syndrome (CFS) criteria. Patients completed questionnaires, and underwent a physical examination and a structured psychiatric evaluation. Critical components of the diagnostic criteria of FM (tender points and diffuse pain) and CFS (persistent debilitating fatigue and four of eight associated symptoms) were examined for their relationship with PTSD.

RESULTS: The prevalence of lifetime PTSD was 20% and lifetime MDD was 42%. Patients who had both tender points and diffuse pain had a higher prevalence of PTSD (OR=3.4, 95% CI 2.0-5.8) compared with those who had neither of these FM criteria. Stratification by MDD and adjustment for sociodemographic factors and chronic fatigue revealed that the association of PTSD with FM criteria was confined to those with MDD. Patients with MDD who met both components of the FM criteria had a three-fold increase in the prevalence of PTSD (95% CI 1.5-7.1); conversely, FM patients without MDD showed no increase in PTSD (OR=1.3, 95% CI 0.5-3.2). The components of the CFS criteria were not significantly associated with PTSD.

CONCLUSION: Optimal clinical care for patients with FM should include an assessment of trauma in general, and PTSD in particular. This study highlights the importance of considering co-morbid MDD as an effect modifier in analyses that explore PTSD in patients with FM.

Source: Roy-Byrne P, Smith WR, Goldberg J, Afari N, Buchwald D. Post-traumatic stress disorder among patients with chronic pain and chronic fatigue. Psychol Med. 2004 Feb;34(2):363-8. http://www.ncbi.nlm.nih.gov/pubmed/14982142

Chronic fatigue syndrome: a review

Abstract:

OBJECTIVE: Chronic fatigue syndrome is an illness characterized by disabling fatigue of at least 6 months, accompanied by several other symptoms. This review summarizes the current state of knowledge about chronic fatigue syndrome.

METHOD: The case definition, prevalence, clinical presentation, evaluation, and prognosis of chronic fatigue syndrome are discussed. Research on the pathophysiology and treatment of chronic fatigue syndrome is reviewed.

RESULTS: Chronic fatigue syndrome is diagnosed on the basis of symptoms. Patients with chronic fatigue syndrome experience significant functional impairment. Pathophysiological abnormalities exist across many domains, suggesting that chronic fatigue syndrome is a heterogeneous condition of complex and multifactorial etiology. Evidence also is beginning to emerge that chronic fatigue syndrome may be familial. Although chronic fatigue syndrome has significant symptom overlap and comorbidity with psychiatric disorders, several lines of research suggest that the illness may be distinct from psychiatric disorders. Patients’ perceptions, attributions, and coping skills, however, may help perpetuate the illness. Treatment for chronic fatigue syndrome is symptom-based and includes pharmacological and behavioral strategies. Cognitive behavior therapy and graded exercise can be effective in treating the fatigue and associated symptoms and disability.

CONCLUSIONS: Chronic fatigue syndrome is unlikely to be caused or maintained by a single agent. Findings to date suggest that physiological and psychological factors work together to predispose an individual to the illness and to precipitate and perpetuate the illness. The assessment and treatment of chronic fatigue syndrome should be multidimensional and tailored to the needs of the individual patient.

Comment in:

On chronic fatigue syndrome. [Am J Psychiatry. 2004]

Source: Afari N, Buchwald D. Chronic fatigue syndrome: a review. Am J Psychiatry. 2003 Feb;160(2):221-36. http://www.ncbi.nlm.nih.gov/pubmed/12562565

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

Coping strategies in twins with chronic fatigue and chronic fatigue syndrome

Abstract:

OBJECTIVES: Individuals with chronic fatigue and chronic fatigue syndrome (CFS) face debilitating symptoms as well as stressful life situations that may result from their condition. The goal of this study was to examine the coping strategies used by fatigue-discordant twin pairs.

METHODS: We utilized a co-twin design to assess how twin pairs discordant for chronic fatigue and CFS cope with stress. All twin pairs were administered the Revised Ways of Coping Checklist.

RESULTS: Overall, the pattern of coping strategies was similar for fatigued and non-fatigued twins. However, twins with chronic fatigue or CFS utilized more avoidance strategies than their non-fatigued counterparts; those with chronic fatigue also used more avoidance relative to problem-focused coping than their co-twins.

CONCLUSIONS: These results suggest that while fatigue-discordant twins generally exhibit similar behavior patterns in order to cope with stress, there may be an association between fatigue and avoidance coping. Future research should focus on the role of avoidance and its relationship to fatiguing illnesses.

Source: Afari N, Schmaling KB, Herrell R, Hartman S, Goldberg J, Buchwald DS. Coping strategies in twins with chronic fatigue and chronic fatigue syndrome. J Psychosom Res. 2000 Jun;48(6):547-54. http://www.ncbi.nlm.nih.gov/pubmed/11033373