Biological phenotypes underpin the physio-somatic symptoms of somatization, depression, and chronic fatigue syndrome

Abstract:

OBJECTIVE: Somatization is a symptom cluster characterized by ‘psychosomatic’ symptoms, that is, medically unexplained symptoms, and is a common component of other conditions, including depression and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This article reviews the data regarding the pathophysiological foundations of ‘psychosomatic’ symptoms and the implications that this has for conceptualization of what may more appropriately be termed physio-somatic symptoms.

METHOD: This narrative review used papers published in PubMed, Scopus, and Google Scholar electronic databases using the keywords: depression and chronic fatigue, depression and somatization, somatization and chronic fatigue syndrome, each combined with inflammation, inflammatory, tryptophan, and cell-mediated immune (CMI).

RESULTS: The physio-somatic symptoms of depression, ME/CFS, and somatization are associated with specific biomarkers of inflammation and CMI activation, which are correlated with, and causally linked to, changes in the tryptophan catabolite (TRYCAT) pathway. Oxidative and nitrosative stress induces damage that increases neoepitopes and autoimmunity that contribute to the immuno-inflammatory processes. These pathways are all known to cause physio-somatic symptoms, including fatigue, malaise, autonomic symptoms, hyperalgesia, intestinal hypermotility, peripheral neuropathy, etc.

CONCLUSION: Biological underpinnings, such as immune-inflammatory pathways, may explain, at least in part, the occurrence of physio-somatic symptoms in depression, somatization, or myalgic encephalomyelitis/chronic fatigue syndrome and thus the clinical overlap among these disorders.

© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comment in

Source: Anderson G, Berk M, Maes M. Biological phenotypes underpin the physio-somatic symptoms of somatization, depression, and chronic fatigue syndrome. Acta Psychiatr Scand. 2014 Feb;129(2):83-97. doi: 10.1111/acps.12182. Epub 2013 Aug 17. https://www.ncbi.nlm.nih.gov/pubmed/23952563

 

Mechanisms of change underlying the efficacy of cognitive behaviour therapy for chronic fatigue syndrome in a specialist clinic: a mediation analysis

Abstract:

BACKGROUND: Several randomized controlled trials (RCTs) have shown that cognitive behavioural psychotherapy (CBT) is an efficacious treatment for chronic fatigue syndrome (CFS). However, little is known about the mechanisms by which the treatment has its effect. The aim of this study was to investigate potential mechanisms of change underlying the efficacy of CBT for CFS. We applied path analysis and introduce novel model comparison approaches to assess a theoretical CBT model that suggests that fearful cognitions will mediate the relationship between avoidance behaviour and illness outcomes (fatigue and social adjustment).

METHOD: Data from 389 patients with CFS who received CBT in a specialist service in the UK were collected at baseline, at discharge from treatment, and at 3-, 6- and 12-month follow-ups. Path analyses were used to assess possible mediating effects. Model selection using information criteria was used to compare support for competing mediational models.

RESULTS: Path analyses were consistent with the hypothesized model in which fear avoidance beliefs at the 3-month follow-up partially mediate the relationship between avoidance behaviour at discharge and fatigue and social adjustment respectively at 6 months.

CONCLUSIONS: The results strengthen the validity of a theoretical model of CBT by confirming the role of cognitive and behavioural factors in CFS.

 

Source: Stahl D, Rimes KA, Chalder T. Mechanisms of change underlying the efficacy of cognitive behaviour therapy for chronic fatigue syndrome in a specialist clinic: a mediation analysis. Psychol Med. 2014 Apr;44(6):1331-44. doi: 10.1017/S0033291713002006. Epub 2013 Aug 12. https://www.ncbi.nlm.nih.gov/pubmed/23931831

 

Kynurenine Pathway Pathologies: do Nicotinamide and Other Pathway Co-Factors have a Therapeutic Role in Reduction of Symptom Severity, Including Chronic Fatigue Syndrome (CFS) and Fibromyalgia (FM)

Abstract:

The definition of dual tryptophan pathways has increased the understanding of the mind-body, body-mind dichotomy. The serotonergic pathway highlights the primary (endogenous) psychiatric disorders. The up-regulation of the kynurenine pathway by physical illnesses can cause neuropathic and immunological disorders1 associated with secondary neuropsychiatric symptoms.

Tryptophan and nicotinamide deficiencies fall within the protein energy malnutrition (PEM) spectrum. They can arise if the kynurenine pathway is stressed by primary or secondary inflammatory conditions and the consequent imbalance of available catabolic/anabolic substrates may adversely influence convalescent phase efficiency. The replacement of depleted or reduced NAD+ levels and other cofactors can perhaps improve the clinical management of these disorders.

Chronic fatigue syndrome (CFS) and fibromyalgia (FM) appear to meet the criteria of a tryptophan-kynurenine pathway disorder with potential neuroimmunological sequelae. Aspects of some of the putative precipitating factors have been previously outlined.2,3 An analysis of the areas of metabolic dysfunction will focus on future directions for research and management.

 

Source: Blankfield A. Kynurenine Pathway Pathologies: do Nicotinamide and Other Pathway Co-Factors have a Therapeutic Role in Reduction of Symptom Severity, Including Chronic Fatigue Syndrome (CFS) and Fibromyalgia (FM). Int J Tryptophan Res. 2013 Jul 21;6(Suppl 1):39-45. doi: 10.4137/IJTR.S11193. Print 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3729338/ (Full article)

 

Chronic fatigue self-management in primary care: a randomized trial

Abstract:

OBJECTIVE: To assess the efficacy of brief fatigue self-management (FSM) for medically unexplained chronic fatigue (UCF) and chronic fatigue syndrome (CFS) in primary care.

METHODS: A randomized controlled design was used wherein 111 patients with UCF or CFS were randomly assigned to two sessions of FSM, two sessions of symptom monitoring support (attention control; AC), or a usual care control condition (UC). Participants were assessed at baseline and at 3 and 12 months after treatment. The primary outcome, the Fatigue Severity Scale, measured fatigue impact on functioning. Analysis was by intention to treat (multiple imputation) and also by per protocol.

RESULTS: A group × time interaction across the 15-month trial showed significantly greater reductions in fatigue impact in the FSM group in comparison with the AC group (p < .023) and the UC group (p < .013). Medium effect sizes for reduced fatigue impact in the FSM group were found in comparison with the AC group (d = 0.46) and the UC group (d = 0.40). The per-protocol analysis revealed large effect sizes for the same comparisons. Clinically significant decreases in fatigue impact were found for 53% of participants in the FSM condition, 14% in the AC condition, and 17% in the UC condition. Dropout rates at the 12-month follow-up were high (42%-53%), perhaps attributable to the burden of monthly telephone calls to assess health care use.

CONCLUSION: A brief self-management intervention for patients with UCF or CFS seemed to be clinically effective for reducing the impact of fatigue on functioning.

Trial Registration clinicaltrials.gov Identifier: NCT00997451.

 

Source: Friedberg F, Napoli A, Coronel J, Adamowicz J, Seva V, Caikauskaite I, Ngan MC, Chang J, Meng H. Chronic fatigue self-management in primary care: a randomized trial. Psychosom Med. 2013 Sep;75(7):650-7. doi: 10.1097/PSY.0b013e31829dbed4. Epub 2013 Aug 6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3785003/ (Full article)

 

Characterising eye movement dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

BACKGROUND: People who suffer from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often report that their eye movements are sluggish and that they have difficulties tracking moving objects. However, descriptions of these visual problems are based solely on patients’ self-reports of their subjective visual experiences, and there is a distinct lack of empirical evidence to objectively verify their claims. This paper presents the first experimental research to objectively examine eye movements in those suffering from ME/CFS.

METHODS: Patients were assessed for ME/CFS symptoms and were compared to age, gender, and education matched controls for their ability to generate saccades and smooth pursuit eye movements.

RESULTS: Patients and controls exhibited similar error rates and saccade latencies (response times) on prosaccade and antisaccade tasks. Patients showed relatively intact ability to accurately fixate the target (prosaccades), but were impaired when required to focus accurately in a specific position opposite the target (antisaccades). Patients were most markedly impaired when required to direct their gaze as closely as possible to a smoothly moving target (smooth pursuit).

CONCLUSIONS: It is hypothesised that the effects of ME/CFS can be overcome briefly for completion of saccades, but that continuous pursuit activity (accurately tracking a moving object), even for a short time period, highlights dysfunctional eye movement behaviour in ME/CFS patients. Future smooth pursuit research may elucidate and improve diagnosis of ME/CFS.

 

Source: Badham SP, Hutchinson CV. Characterising eye movement dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome. Graefes Arch Clin Exp Ophthalmol. 2013 Dec;251(12):2769-76. doi: 10.1007/s00417-013-2431-3. Epub 2013 Aug 6. https://www.ncbi.nlm.nih.gov/pubmed/23918092

 

Unstimulated cortisol secretory activity in everyday life and its relationship with fatigue and chronic fatigue syndrome: a systematic review and subset meta-analysis

Abstract:

The hypothalamic-pituitary-adrenal (HPA) axis is a psychoneuroendocrine regulator of the stress response and immune system, and dysfunctions have been associated with outcomes in several physical health conditions. Its end product, cortisol, is relevant to fatigue due to its role in energy metabolism.

The systematic review examined the relationship between different markers of unstimulated salivary cortisol activity in everyday life in chronic fatigue syndrome (CFS) and fatigue assessed in other clinical and general populations. Search terms for the review related to salivary cortisol assessments, everyday life contexts, and fatigue. All eligible studies (n=19) were reviewed narratively in terms of associations between fatigue and assessed cortisol markers, including the cortisol awakening response (CAR), circadian profile (CP) output, and diurnal cortisol slope (DCS).

Subset meta-analyses were conducted of case-control CFS studies examining group differences in three cortisol outcomes: CAR output; CAR increase; and CP output. Meta-analyses revealed an attenuation of the CAR increase within CFS compared to controls (d=-.34) but no statistically significant differences between groups for other markers. In the narrative review, total cortisol output (CAR or CP) was rarely associated with fatigue in any population; CAR increase and DCS were most relevant.

Outcomes reflecting within-day change in cortisol levels (CAR increase; DCS) may be the most relevant to fatigue experience, and future research in this area should report at least one such marker. Results should be considered with caution due to heterogeneity in one meta-analysis and the small number of studies.

Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

 

Source: Powell DJ, Liossi C, Moss-Morris R, Schlotz W. Unstimulated cortisol secretory activity in everyday life and its relationship with fatigue and chronic fatigue syndrome: a systematic review and subset meta-analysis. Psychoneuroendocrinology. 2013 Nov;38(11):2405-22. doi: 10.1016/j.psyneuen.2013.07.004. Epub 2013 Aug 2. http://www.psyneuen-journal.com/article/S0306-4530(13)00254-0/fulltext (Full article)

 

A pilot registry of unexplained fatiguing illnesses and chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) has no diagnostic clinical signs or biomarkers, so diagnosis requires ruling out conditions with similar signs and symptoms. We conducted a pilot registry of unexplained fatiguing illnesses and CFS to determine the feasibility of establishing and operating a registry and implementing an education outreach initiative. The pilot registry was conducted in Bibb County, Georgia. Patient referrals were obtained from healthcare providers who were identified by using various education outreach initiatives. These referrals were later supplemented with self-referrals by members of a local CFS support group. All patients meeting referral criteria were invited to participate in a screening interview to determine eligibility. If patients met registry criteria, they were invited to a one-day clinic for physical and laboratory evaluations. We classified patients based on the 1994 case definition.

RESULTS: We registered 827 healthcare providers. Forty-two providers referred 88 patients, and 58 patients (66%) completed clinical evaluation. Of the 188 CFS support group members, 53 were self-referred and 46 (87%) completed the clinical evaluation. Of the 104 participants completing evaluation, 36% (n = 37) met the criteria for CFS, 17% (n = 18) had insufficient fatigue or symptoms (ISF), and 47% (n = 49) were found to have exclusionary medical or psychiatric illnesses. Classification varied significantly by type of referral but not by previous history of CFS diagnosis. Healthcare providers referred more patients who were classified as CFS as compared to support group referrals in which more exclusionary conditions were identified. Family practice and internal medicine specialties made the most referrals and had the highest number of CFS cases. We conducted three CME events, held three “Meet and Greet” sessions, visited four large clinical health practices and health departments, mailed five registry newsletters, and conducted in-person office visits as part of education outreach, which contributed to patient referrals.

CONCLUSIONS: Referrals from healthcare providers and self-referrals from the patient support group were important to registry enrollment. The number of potentially treatable conditions that were identified highlights the need for continued medical management in this population, as well as the limitations of registries formed without clinical examination. Education initiatives were successful in part because of partnerships with local organizations.

 

Source: Brimmer DJ, Maloney E, Devlin R, Jones JF, Boneva R, Nagler C, LeRoy L, Royal S, Tian H, Lin JM, Kasten J, Unger ER. A pilot registry of unexplained fatiguing illnesses and chronic fatigue syndrome. BMC Res Notes. 2013 Aug 2;6:309. doi: 10.1186/1756-0500-6-309. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3750716/ (Full article)

 

Contrasting Chronic Fatigue Syndrome versus Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

BACKGROUND: Much debate is transpiring regarding whether chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) are different illnesses. Several prior studies that compared the Fukuda et al. CFS criteria to the Canadian ME/CFS criteria found that the Canadian criteria identified patients with more functional impairments and greater physical, mental, and cognitive problems than those who met Fukuda et al. criteria.[3,4] These samples were located in the Chicago metropolitan area, so the results could not be generalized to other locations. In addition, past studies used a symptom questionnaire that was not specifically developed to tap the Canadian criteria.

PURPOSE: The present comparative study of CFS and ME/CFS criteria was intended to correct the methodological problems of prior studies.

METHODS: This article used data from three distinct samples to compare patients who met criteria for the ME/CFS Canadian clinical case definition [1] to those who met the Fukuda et al. CFS case definition.[2].

RESULTS: Findings indicated that fewer individuals met the Canadian criteria than the Fukuda et al. criteria. Those who met the Canadian criteria evidenced more severe symptoms and physical functioning impairment.

CONCLUSIONS: Future research should continue to compare existing case definitions and determine which criteria best select for this illness.

 

Source: Jason LA, Brown A, Evans M, Sunnquist M, Newton JL. Contrasting Chronic Fatigue Syndrome versus Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Fatigue. 2013 Jun 1;1(3):168-183. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3728084/ (Full article)

 

Migraine in gulf war illness and chronic fatigue syndrome: prevalence, potential mechanisms, and evaluation

Abstract:

OBJECTIVE: To assess the prevalence of headache subtypes in Gulf War Illness (GWI) and Chronic Fatigue Syndrome (CFS) compared to controls.

BACKGROUND: Approximately, 25% of the military personnel who served in the 1990-1991 Persian Gulf War have developed GWI. Symptoms of GWI and CFS have considerable overlap, including headache complaints. Migraines are reported in CFS. The type and prevalence of headaches in GWI have not been adequately assessed.

METHODS: 50 GWI, 39 CFS and 45 controls had structured headache evaluations based on the 2004 International Headache Society criteria. All subjects had history and physical examinations, fatigue and symptom related questionnaires, measurements of systemic hyperalgesia (dolorimetry), and assessments for exclusionary conditions.

RESULTS: Migraines were detected in 64% of GWI (odds ratio = 11.6 [4.1-32.5]) (mean [±95% CI]) and 82% of CFS subjects (odds ratio = 22.5 [7.8-64.8]) compared to only 13% of controls. There was a predominance of females in the CFS compared to GWI and controls. However, migraine status was independent of gender in GWI and CFS groups (x (2) = 2.7; P = 0.101). Measures of fatigue, pain, and other ancillary criteria were comparable between GWI and CFS subjects with and without headache.

CONCLUSION: The high prevalence of migraine in CFS was confirmed and extended to GWI subjects. GWI and CFS may share dysfunctional central pathophysiological pathways that contribute to migraine and subjective symptoms. The high migraine prevalence warrants the inclusion of a structured headache evaluation in GWI and CFS subjects, and treatment when present.

 

Source: Rayhan RU, Ravindran MK, Baraniuk JN. Migraine in gulf war illness and chronic fatigue syndrome: prevalence, potential mechanisms, and evaluation. Front Physiol. 2013 Jul 24;4:181. doi: 10.3389/fphys.2013.00181. ECollection 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3721020/ (Full article)

 

Allostatic overload in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterised by diverse symptoms such as fatigue, pain, sleep disturbance and autonomic dysfunction. There remains to be a singular biomarker identified for this illness, hence numerous theories about its development and perpetuation have been posited in the literature.

This brief report presents the model of ‘allostasis’ as a framework for understanding ME/CFS, specifically the notion that the physiological mechanisms employed in the body to deal with stress termed here as ‘allostatic states’ (e.g. elevation of inflammatory cytokines), may in and of themselves contribute to the perpetuation of the disorder. This theoretical assertion has important consequences for the understanding of ME/CFS and treatment; rather than searching for a singular pathogen responsible for this condition, ME/CFS can be conceptualised as a maladaptive stress disorder and interventions aimed at addressing the allostatic states may be incorporated into current symptom management programmes.

Copyright © 2013 Elsevier Ltd. All rights reserved.

 

Source: Arroll MA. Allostatic overload in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Med Hypotheses. 2013 Sep;81(3):506-8. doi: 10.1016/j.mehy.2013.06.023. Epub 2013 Jul 11. https://www.ncbi.nlm.nih.gov/pubmed/23850395