Electrodermal dissociation of chronic fatigue and depression: evidence for distinct physiological mechanisms

Sleep-wake variations of electrodermal activity in bipolar disorder

BACKGROUND

Affective states influence the sympathetic nervous system, inducing variations in electrodermal activity (EDA), however, EDA association with bipolar disorder (BD) remains uncertain in real-world settings due to confounders like physical activity and temperature. We analysed EDA separately during sleep and wakefulness due to varying confounders and potential differences in mood state discrimination capacities.

METHODS

We monitored EDA from 102 participants with BD including 35 manic, 29 depressive, 38 euthymic patients, and 38 healthy controls (HC), for 48 h. Fifteen EDA features were inferred by mixed-effect models for repeated measures considering sleep state, group and covariates.

RESULTS

Thirteen EDA feature models were significantly influenced by sleep state, notably including phasic peaks (p < 0.001). During wakefulness, phasic peaks showed different values for mania (M [SD] = 6.49 [5.74, 7.23]), euthymia (5.89 [4.83, 6.94]), HC (3.04 [1.65, 4.42]), and depression (3.00 [2.07, 3.92]). Four phasic features during wakefulness better discriminated between HC and mania or euthymia, and between depression and euthymia or mania, compared to sleep. Mixed symptoms, average skin temperature, and anticholinergic medication affected the models, while sex and age did not.

CONCLUSION

EDA measured from awake recordings better distinguished between BD states than sleep recordings, when controlled by confounders.

Major Depressive Disorder and Chronic Fatigue Syndrome Show Characteristic Heart Rate Variability Profiles Reflecting Autonomic Dysregulations: Differentiation by Linear Discriminant Analysis

Major depressive disorder (MDD) and chronic fatigue syndrome (CFS) have overlapping symptoms, and differentiation is important to administer the proper treatment. The present study aimed to assess the usefulness of heart rate variability (HRV) indices. Frequency-domain HRV indices, including high-frequency (HF) and low-frequency (LF) components, their sum (LF+HF), and their ratio (LF/HF), were measured in a three-behavioral-state paradigm composed of initial rest (Rest), task load (Task), and post-task rest (After) periods to examine autonomic regulation. It was found that HF was low at Rest in both disorders, but was lower in MDD than in CFS. LF and LF+HF at Rest were low only in MDD. Attenuated responses of LF, HF, LF+HF, and LF/HF to task load and an excessive increase in HF at After were found in both disorders. The results indicate that an overall HRV reduction at Rest may support a diagnosis of MDD. HF reduction was found in CFS, but with a lesser severity. Response disturbances of HRV to Task were observed in both disorders, and would suggest the presence of CFS when the baseline HRV has not been reduced. Linear discriminant analysis using HRV indices was able to differentiate MDD from CFS, with a sensitivity and specificity of 91.8% and 100%, respectively. HRV indices in MDD and CFS show both common and different profiles, and can be useful for the differential diagnosis.

Galvanic Skin Response Features in Psychiatry and Mental Disorders: A Narrative Review

This narrative review is aimed at presenting the galvanic skin response (GSR) Biofeedback method and possibilities for its application in persons with mental disorders as a modern form of neurorehabilitation. In the treatment of mental disorders of various backgrounds and courses, attention is focused on methods that would combine pharmacological treatment with therapies improving functioning. Currently, the focus is on neuronal mechanisms which, being physiological markers, offer opportunities for correction of existing deficits. One such indicator is electrodermal activity (EDA), providing information about emotions, cognitive processes, and behavior, and thus, about the function of various brain regions. Measurement of the galvanic skin response (GSR), both skin conductance level (SCL) and skin conductance responses (SCR), is used in diagnostics and treatment of mental disorders, and the training method itself, based on GSR Biofeedback, allows for modulation of the emotional state depending on needs occurring. Summary: It is relatively probable that neurorehabilitation based on GSR-BF is a method worth noticing, which-in the future-can represent an interesting area of rehabilitation supplementing a comprehensive treatment for people with mental disorders.

Reduced Parasympathetic Reactivation during Recovery from Exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Although autonomic nervous system (ANS) dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) has been proposed, conflicting evidence makes it difficult to draw firm conclusions regarding ANS activity at rest in ME/CFS patients. Although severe exercise intolerance is one of the core features of ME/CFS, little attempts have been made to study ANS responses to physical exercise. Therefore, impairments in ANS activation at rest and following exercise were examined using a case-control study in 20 ME/CFS patients and 20 healthy people. Different autonomous variables, including cardiac, respiratory, and electrodermal responses were assessed at rest and following an acute exercise bout. At rest, parameters in the time-domain represented normal autonomic function in ME/CFS, while frequency-domain parameters indicated the possible presence of diminished (para)sympathetic activation. Reduced parasympathetic reactivation during recovery from exercise was observed in ME/CFS. This is the first study showing reduced parasympathetic reactivation during recovery from physical exercise in ME/CFS. Delayed HR recovery and/or a reduced HRV as seen in ME/CFS have been associated with poor disease prognosis, high risk for adverse cardiac events, and morbidity in other pathologies, implying that future studies should examine whether this is also the case in ME/CFS and how to safely improve HR recovery in this population.

Early versus Late Modality Fusion of Deep Wearable Sensor Features for Personalized Prediction of Tomorrow's Mood, Health, and Stress. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020;2020:5896-5899. [PMID: 33019316 DOI: 10.1109/embc44109.2020.9175463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Predicting mood, health, and stress can sound an early alarm against mental illness. Multi-modal data from wearable sensors provide rigorous and rich insights into one's internal states. Recently, deep learning-based features on continuous high-resolution sensor data have outperformed statistical features in several ubiquitous and affective computing applications including sleep detection and depression diagnosis. Motivated by this, we investigate multi-modal data fusion strategies featuring deep representation learning of skin conductance, skin temperature, and acceleration data to predict self-reported mood, health, and stress scores (0 - 100) of college students (N = 239). Our cross-validated results from the early fusion framework exhibit a significantly higher (p <; 0.05) prediction precision over the late fusion for unseen users. Therefore, our findings call attention to the benefits of fusing physiological data modalities at a low level and corroborate the predictive efficacy of the deeply learned features.

Surface temperature elevated by chronic and intermittent stress

Stress in homeothermic animals is associated with raised body core temperature and altered patterns of peripheral blood flow. During acute stress, peripheral vasoconstriction causes a short-lived drop in surface temperature that can be detected non-invasively using infrared thermography (IRT). Whether and how skin temperature changes under chronic stress, and hence the potential of IRT in chronic stress detection, is unknown. We explored the impact of withdrawing environmental enrichments and intermittent routine handling on long-term skin temperature in laying hens (Gallus gallus domesticus). Immediately following enrichment withdrawal, comb, face and eye temperature dropped, suggesting this was acutely stressful. In the 3 weeks that followed, barren-housed hens displayed behavioural markers of frustration. Whilst control birds, housed in enriched conditions, showed a decline over weeks in both comb temperature and baseline corticosterone levels, barren-housed hens had no change in comb temperature and an increase in corticosterone. By the trial end, comb temperature (but not corticosterone) was significantly higher in barren-housed hens. This change in parameters over time may reflect cumulative impacts of enrichment withdrawal in barren pens and/or, as hens were young and maturing, age-related changes in controls. Comb, face and eye temperature were also higher on days following routine handling, and comb temperature higher on other days in hens that were regularly handled for blood sampling than for a less intensive weighing protocol. Together, these data support comb, face and eye surface temperature increase as a long-term marker of stress exposure in laying hens. It is important to recognise that the strength and even direction of these effects may vary with thermoregulatory and energetic context. However, in laboratory and indoor-reared farm animals that live in carefully managed environments, IRT of the skin can potentially be used to non-invasively monitor chronic and intermittent stress exposure.

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We measured surface temperature (ST) profile in hens subject to long term and intermittent stress.

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The impact of stressors was validated using established behavioural and hormonal markers.

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Enrichment withdrawal caused a short term drop in ST but living in a barren environment increased ST.

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Hens also had higher ST on days following handling or when subject to more intense handling methods.

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Thermal imaging of ST offers a non-invasive approach toward chronic stress monitoring.

The association between electrodermal activity (EDA), depression and suicidal behaviour: A systematic review and narrative synthesis

BACKGROUND

Electrodermal activity (EDA) and other peripheral autonomic electrical parameters have been used as indicators of emotional states, including depressive states and suicidal state. We aimed to review EDA research systematically, focusing on EDA's usefulness as a biomarker for depression and suicidal behaviour.

METHODS

We searched MEDLINE, Scopus, Cochrane Library, and Web of Science databases, following PRISMA guidelines. The initial screening of articles was based on titles and abstracts; then the full text was reviewed. A preliminary synthesis of findings was developed using tables, thematic analysis and quality ratings.

RESULTS

1287 articles were screened and 77 relevant studies were identified and included in the systematic review. The studies were fairly consistent in maintaining that hypoactive electrodermal response is an established feature of patients affected by depression. There is also preliminary evidence that monitoring EDA may help to differentiate the phases of mood disorders. A few studies provided evidence that EDA can be used to differentiate acutely suicidal subjects from depressed patients who are not severely suicidal. Although EDA has been shown to be a valid, sensitive marker of suicidal ideation, suicide attempts and violent suicidal behaviour, it also seems to be influenced to some extent by antidepressant treatment.

CONCLUSIONS

Most of the studies summarised in this review are quite outdated and employed a variety of designs and methods to evaluate EDA. This limits the generalisability of the results and makes it difficult to draw clear conclusions about the role of EDA in real-world settings. Electrodermal hypoactivity seems to be a reliable feature of depression and a valid marker of suicidal risk. Nevertheless, the potential utility of EDA in diagnosis, prevention, and treatment planning for depression and suicidal behaviour, should be thoroughly studied.

Increased risk of organic erectile dysfunction in patients with chronic fatigue syndrome: a nationwide population-based cohort study

Chronic fatigue syndrome (CFS) is a complex disorder characterized by profound and persistent fatigue and several comorbidities. CFS was previously reported to be associated with female sexual dysfunction. We propose that CFS might also be associated with organic erectile dysfunction (organic ED). We conducted a retrospective cohort study by using data from the National Health Insurance (NHI) Research Database. We identified 2156 male patients who were newly diagnosed with CFS between January 1, 2003 and December 31, 2006. After excluding those younger than 20 years and prevalent cases, 1976 patients were subjected to analysis, and 7904 people served as healthy controls. All study subjects were followed up from the index date to the date of organic ED diagnosis, withdrawal from the NHI program, or the end of 2011. Compared with the non-CFS cohort, the incidence density rate of organic ED was 1.88-fold higher than that in the CFS cohort (3.23 vs. 1.73 per 1000 person-years) with an adjusted hazard ratio (HR) of 1.88 (95% CI = 1.26-2.81) when adjusting for sex and comorbidities. The combined impacts of patients with CFS and cardiovascular disease (CVD), diabetes mellitus (DM), chronic kidney disease (CKD), depression, and anxiety showed a significant by joint association with organic ED risk compared with patients with no CFS and no counterpart comorbidity. The greatest magnitude of adjusted HR of ED for CFS was observed in individuals without any comorbidity (3.87, 1.95-7.66). The incidence of organic ED is higher among males aged 40 years and over for both CFS and non-CFS cohorts. As the number of comorbidity increases, the incidence of organic ED increases in males without CFS. Higher incidence of organic ED was observed in males with CVD, DM, CKD, depression, or anxiety for both CFS and non-CFS cohorts.

Autonomic correlations with MRI are abnormal in the brainstem vasomotor centre in Chronic Fatigue Syndrome

Autonomic changes are often associated with the chronic fatigue syndrome (CFS), but their pathogenetic role is unclear and brain imaging investigations are lacking. The vasomotor centre and, through it, nuclei in the midbrain and hypothalamus play a key role in autonomic nervous system regulation of steady state blood pressure (BP) and heart rate (HR). In this exploratory cross-sectional study, BP and HR, as indicators of autonomic function, were correlated with volumetric and T1- and T2-weighted spin-echo (T1w and T2w) brain MRI in 25 CFS subjects and 25 normal controls (NC). Steady state BP (systolic, diastolic and pulse pressure) and HR in two postures were extracted from 24 h blood pressure monitoring. We performed (1) MRI versus autonomic score interaction-with-group regressions to detect locations where regression slopes differed in the CFS and NC groups (collectively indicating abnormality in CFS), and (2) MRI regressions in the CFS and NC groups alone to detect additional locations with abnormal correlations in CFS. Significant CFS regressions were repeated controlling for anxiety and depression (A&D). Abnormal regressions were detected in nuclei of the brainstem vasomotor centre, midbrain reticular formation and hypothalamus, but also in limbic nuclei involved in stress responses and in prefrontal white matter. Group comparisons of CFS and NC did not find MRI differences in these locations. We propose therefore that these regulatory nuclei are functioning correctly, but that two-way communication between them is impaired in CFS and this affects signalling to/from peripheral effectors/sensors, culminating in inverted or magnified correlations. This single explanation for the diverse abnormal correlations detected here consolidates the conclusion for a brainstem/midbrain nerve conduction deficit inferred earlier (Barnden et al., 2015). Strong correlations were also detected in isolated NC regressions.

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For the first time in CFS, we performed MRI regressions with steady state BP and HR.

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Vasomotor centre, midbrain and hypothalamus correlations were abnormal in CFS.

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MRI group comparisons between CFS and controls detected no differences.

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Regulatory nuclei and peripheral effectors/sensors appear to function correctly.

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Signalling between brainstem/midbrain regulatory nuclei appears to be impaired.

Malfunctioning of the autonomic nervous system in patients with chronic fatigue syndrome: a systematic literature review

INTRODUCTION

It is hypothesised that the autonomic nervous system responds differently to various stressors in patients with chronic fatigue syndrome (CFS) compared with healthy controls. The goal is to systematically review the scientific literature addressing the functioning of the autonomic nervous system in patients with CFS.

MATERIALS AND METHODS

All studies that were identified through electronic databases (PubMed and Web of Science) were screened for eligibility based on the selection criteria and assessed (two independent raters) for methodological quality using a methodological checklist for case-control studies.

RESULTS

Twenty-seven case-control studies were included. The methodological quality varied between 50% and 71·4%. Some studies showed different responses to head-up tilt and other autonomous testing.

CONCLUSION

Although comparison between the included case-control studies was difficult, we can conclude that there are differences in autonomous response between patients with CFS and healthy controls. The heart rate dynamic response during the head-up tilt test differs between patients with CFS and healthy controls, supporting the increased prevalence of postural orthostatic tachycardia syndrome. The autonomic response can be useful for the diagnosis of CFS.

A Constructive Debate With the CDC on the Empirical Case Definition of Chronic Fatigue Syndrome

The Centers for Disease Control and Prevention (CDC) estimates of the prevalence of chronic fatigue syndrome (CFS) have dramatically increased over the past 20 years, from 0.002% to 2.54%. Once considered a rare disorder, CFS is now characterized as a more common chronic health condition, with prevalence numbers suggesting that more than 4 million people in the United States have it. The authors’ research group proposes that selection criteria for CFS cases have broadened and provides data indicating 38% of those with a Major Depressive Disorder were misclassified as having CFS under the new CDC empirical case definition. The authors respond to concerns cited in Reeves, Gurbaxani, Lin, and Unger (2009). Given the importance of standardizing procedures for identifying CFS, more research is needed using different criteria on samples of patients with CFS and other illnesses. The erroneous inclusion of people with primary psychiatric conditions in CFS samples has detrimental consequences for interpreting epidemiologic and etiological findings.

Evaluating the Centers for Disease Control’s Empirical Chronic Fatigue Syndrome Case Definition

The Centers for Disease Control and Prevention (CDC) recently developed an empirical case definition that specifies criteria and instruments to diagnose chronic fatigue syndrome (CFS) in order to bring more methodological rigor to the current CFS case definition. The present study investigated this new definition with 27 participants with a diagnosis of CFS and 37 participants with a diagnosis of a Major Depressive Disorder. Participants completed questionnaires measuring disability, fatigue, and symptoms. Findings indicated that 38% of those with a diagnosis of a Major Depressive Disorder were misclassified as having CFS using the new CDC definition. Given the CDC’s stature and respect in the scientific world, this new definition might be widely used by investigators and clinicians. This might result in the erroneous inclusion of people with primary psychiatric conditions in CFS samples, with detrimental consequences for the interpretation of epidemiologic, etiologic, and treatment efficacy findings for people with CFS.

Abnormal thermoregulatory responses in adolescents with chronic fatigue syndrome: relation to clinical symptoms

OBJECTIVES

Chronic fatigue syndrome is a common and disabling disease of unknown etiology. Accumulating evidence indicates dysfunction of the autonomic nervous system. To further explore the pathophysiology of chronic fatigue syndrome, we investigated thermoregulatory responses dependent on catecholaminergic effector systems in adolescent patients with chronic fatigue syndrome.

PATIENTS AND METHODS

A consecutive sample of 15 patients with chronic fatigue syndrome aged 12 to 18 years and a volunteer sample of 57 healthy control subjects of equal gender and age distribution were included. Plasma catecholamines and metanephrines were measured before and after strong cooling of 1 hand. Acral skin blood flow, tympanic temperature, heart rate, and mean blood pressure were measured during moderate cooling of 1 hand. In addition, clinical symptoms indicative of thermoregulatory disturbances were recorded.

RESULTS

Patients with chronic fatigue syndrome reported significantly more shivering, sweating, sudden change of skin color, and feeling unusually warm. At baseline, patients with chronic fatigue syndrome had higher levels of norepinephrine, heart rate, epinephrine, and tympanic temperature than control subjects. During cooling of 1 hand, acral skin blood flow was less reduced, vasoconstrictor events occurred at lower temperatures, and tympanic temperature decreased more in patients with chronic fatigue syndrome compared with control subjects. Catecholamines increased and metanephrines decreased similarly in the 2 groups.

CONCLUSIONS

Adolescent patients with chronic fatigue syndrome have abnormal catecholaminergic-dependent thermoregulatory responses both at rest and during local skin cooling, supporting a hypothesis of sympathetic dysfunction and possibly explaining important clinical symptoms.

Psychophysiological responses in patients with fibromyalgia syndrome

Physical and emotional stress and altered reactivity of the autonomic nervous system have been implicated in the development and maintenance of fibromyalgia syndrome (FMS). This study investigated blood pressure, heart rate (HR), skin conductance levels (SCL), and surface electromyograms (EMG) from the trapezius muscle in 30 FMS patients and 30 age- and sex-matched healthy controls (HCs). All measures were continuously recorded during baseline (BL), social conflict, mental arithmetic, and relaxation tasks. The FMS patients showed significantly higher stress ratings and self-reported stress responses. Baseline EMG levels were significantly lower, and BL HR was significantly elevated. During both stress tasks, HR reactivity was significantly lower, and SCL reactivity was significantly higher in the FMS group. This pattern of low BL muscle tension and high BL HR, along with low HR and high SCL reactivity to stress, is discrepant to other chronic pain syndromes and suggests unique psychophysiological features associated with FMS. Several potential mechanisms for these psychophysiological responses are discussed.

Evaluation of maximal exercise performance, fatigue, and depression in athletes with acquired chronic training intolerance

OBJECTIVE

This study compared differences in maximal strength and aerobic capacity and symptoms of fatigue and depression in athletes with acquired training intolerance (ATI) and control athletes (CON) matched for age and current training volume who did not have symptoms of excessive or chronic fatigue associated with their sporting activity.

SETTING

University of Cape Town, Sports Science Institute of South Africa.

PARTICIPANTS

Twenty ATI and 10 CON athletes participated in the trial. Although the ATI athletes reported symptoms of excessive fatigue during exercise, or symptoms of fatigue that occurred at rest and during activities of daily living, they did not fulfill the criteria for a diagnosis of chronic fatigue syndrome.

MAIN OUTCOME MEASURES

A training and comprehensive medical history was recorded from all subjects. The Beck Depression Inventory Short Form (BDI-SF) was used to assess levels of depression in both ATI and control subjects. Maximal force output during a 5-second isometric voluntary knee extensor muscle contraction, and maximal aerobic capacity (VO2max), maximal heart rate (HRmax), and maximal blood lactate concentrations during a treadmill running test were measured in all subjects.

RESULTS

There were no differences in maximal isometric force output, peak treadmill running speed, VO2max, HRmax, or blood lactate concentration at rest or after maximal exercise testing between the ATI and CON athletes. However, the BDI-SF scores were higher in the ATI (7.7 +/- 6.6 arbitrary units) than in the CON athletes (1.7 +/- 1.5 arbitrary units; (P = 0.0052).

CONCLUSIONS

These findings suggest that the symptoms of excessive fatigue and acquired training intolerance described by these ATI athletes do not affect their maximal isometric and maximal aerobic capacity, and may be associated with psychologic depression in these athletes.

Chronic fatigue syndrome: the need for subtypes

Chronic fatigue syndrome (CFS) is an important condition confronting patients, clinicians, and researchers. This article provides information concerning the need for appropriate diagnosis of CFS subtypes. We first review findings suggesting that CFS is best conceptualized as a separate diagnostic entity rather than as part of a unitary model of functional somatic distress. Next, research involving the case definitions of CFS is reviewed. Findings suggest that whether a broad or more conservative case definition is employed, and whether clinic or community samples are recruited, these decisions will have a major influence in the types of patients selected. Review of further findings suggests that subtyping individuals with CFS on sociodemographic, functional disability, viral, immune, neuroendocrine, neurology, autonomic, and genetic biomarkers can provide clarification for researchers and clinicians who encounter CFS' characteristically confusing heterogeneous symptom profiles. Treatment studies that incorporate subtypes might be particularly helpful in better understanding the pathophysiology of CFS. This review suggests that there is a need for greater diagnostic clarity, and this might be accomplished by subgroups that integrate multiple variables including those in cognitive, emotional, and biological domains.