MRS Shows Regionally Increased Glutamate Levels among Patients with Exhaustion Syndrome Due to Occupational Stress

Neural and cortisol responses to acute psychosocial stress in work-related burnout: The Regensburg Burnout Project

BACKGROUND

While several attempts have been made to elucidate the pathophysiology of burnout, neural stress responses have not yet been investigated. Therefore, the aim of this study was to examine salivary cortisol and - for the first time - neural responses to acute psychosocial stress within a strictly specified sample consisting of individuals suffering from burnout (BO group) and a healthy comparison group (HC group).

METHODS

After a multi-stage recruitment procedure based on burnout symptomatology and pathogenesis, 55 individuals suffering from burnout (25 women) and 61 individuals serving as HC group (31 women) out of an initial sample of 1022 volunteers were exposed to acute psychosocial stress during functional magnetic resonance imaging (fMRI) applying ScanSTRESS.

RESULTS

No differences were found between the BO and the HC group with respect to cortisol and mean neural stress responses. However, an exploratory comparison of neural stress responses of the first and second run of ScanSTRESS (exposure-time effect) revealed group-specific response patterns in one cluster peaking in the left dorsal anterior cingulate cortex (dACC). While the neural activation of the HC group was higher in the first compared to the second run of ScanSTRESS (i.e., decreasing activation), this pattern was reversed in the BO group (i.e., increasing activation).

CONCLUSIONS

Our analysis mainly did not provide evidence for altered acute cortisol and mean neural stress responses in burnout. However, the BO group was characterized by a limited capacity to show decreasing activation over stress exposure-time and exhibited instead increasing activation. Importantly, this group difference manifested in the left dACC which is both involved in neural stress processing and affected in individuals suffering from burnout. Given the present results, it seems promising to further examining temporal dynamics of neural stress responses in (sub-) clinical conditions such as burnout.

Occupational stress is associated with sex and subregion specific modifications of the amygdala volumes

Background: Despite the rapid increase in reports of exhaustion syndrome (ES) due to daily occupational stress, the mechanisms underlying ES are unknown. In the present study, we investigated whether occupational ES is associated with specific modifications of the subfields of the amygdala and hippocampus resembling those described in other chronic stress conditions. Special focus was paid to possible sex differences.Methods: As a follow up to our previous studies of occupational ES, we carried out MRI-based subfield segmentation of the hippocampus and amygdala volumes in 58 patients with occupational ES (22 males) and 65 age-matched controls (27 males) (age range 30-46 years).Results: There was a significant and bilateral enlargement of the lateral, basal and central nucleus of the amygdala in patients with ES (corrected for the total intracranial volume (ICV)). These differences were detected only in females. Higher values in the right central and right basal amygdala remained when the whole amygdala volume was used as reference, instead of the ICV. Notably, in female patients the volumes of these specific nuclei were positively correlated with the degree of perceived stress. No changes in the hippocampus subfields were detected in female or male patients.Conclusions: The findings underline that ES is a chronic stress condition, suggesting that not only extreme forms of stress, but also the everyday stress is associated with localized differences from controls in the amygdala. The absence of significant alterations among men with ES despite a similar degree of perceived stress supports the notion that women seem more susceptible to stress-related cerebral changes, and may explain the higher prevalence of ES among women.

Meta-analysis and open-source database for in vivo brain Magnetic Resonance spectroscopy in health and disease

Proton (1H) Magnetic Resonance Spectroscopy (MRS) is a non-invasive tool capable of quantifying brain metabolite concentrations in vivo. Prioritization of standardization and accessibility in the field has led to the development of universal pulse sequences, methodological consensus recommendations, and the development of open-source analysis software packages. One on-going challenge is methodological validation with ground-truth data. As ground-truths are rarely available for in vivo measurements, data simulations have become an important tool. The diverse literature of metabolite measurements has made it challenging to define ranges to be used within simulations. Especially for the development of deep learning and machine learning algorithms, simulations must be able to produce accurate spectra capturing all the nuances of in vivo data. Therefore, we sought to determine the physiological ranges and relaxation rates of brain metabolites which can be used both in data simulations and as reference estimates. Using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, we've identified relevant MRS research articles and created an open-source database containing methods, results, and other article information as a resource. Using this database, expectation values and ranges for metabolite concentrations and T2 relaxation times are established based upon a meta-analyses of healthy and diseased brains.

Meta-analysis and Open-source Database for In Vivo Brain Magnetic Resonance Spectroscopy in Health and Disease

Proton ( 1 H) Magnetic Resonance Spectroscopy (MRS) is a non-invasive tool capable of quantifying brain metabolite concentrations in vivo . Prioritization of standardization and accessibility in the field has led to the development of universal pulse sequences, methodological consensus recommendations, and the development of open-source analysis software packages. One on-going challenge is methodological validation with ground-truth data. As ground-truths are rarely available for in vivo measurements, data simulations have become an important tool. The diverse literature of metabolite measurements has made it challenging to define ranges to be used within simulations. Especially for the development of deep learning and machine learning algorithms, simulations must be able to produce accurate spectra capturing all the nuances of in vivo data. Therefore, we sought to determine the physiological ranges and relaxation rates of brain metabolites which can be used both in data simulations and as reference estimates. Using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, we've identified relevant MRS research articles and created an open-source database containing methods, results, and other article information as a resource. Using this database, expectation values and ranges for metabolite concentrations and T 2 relaxation times are established based upon a meta-analyses of healthy and diseased brains.

Exhaustion disorder: scoping review of research on a recently introduced stress-related diagnosis

BACKGROUND

Symptoms related to chronic stress are prevalent and entail high societal costs, yet there is a lack of international consensus regarding diagnostics and treatment. A new stress-related diagnosis, exhaustion disorder, was introduced into the Swedish version of ICD-10 in 2005. Since then, use of the diagnosis has increased rapidly.

AIMS

To create the first comprehensive synthesis of research on exhaustion disorder to report on the current state of knowledge. Preregistration: Open Science Framework (http://www.w3.org/1999/xlink">osf.io), doi 10.17605/OSF.IO/VFDKW.

METHOD

A PRISMA-guided scoping review of all empirical studies of exhaustion disorder was conducted. Searches were run in the MEDLINE, PsycInfo and Web of Science databases. Data were systematically charted and thematically categorised based on primary area of investigation.

RESULTS

Eighty-nine included studies were sorted into six themes relating to lived experience of exhaustion disorder (n = 9), symptom presentation and course (n = 13), cognitive functioning (n = 10), biological measures (n = 24), symptom measurement scales (n = 4) and treatment (n = 29). Several studies indicated that individuals with exhaustion disorder experience a range of psychiatric and somatic symptoms beyond fatigue, but robust findings within most thematic categories were scarce. The limited number of studies, lack of replication of findings and methodological limitations (e.g. small samples and scarcity of specified primary outcomes) preclude firm conclusions about the diagnostic construct.

CONCLUSIONS

More research is needed to build a solid knowledge base for exhaustion disorder. International collaboration regarding the conceptualisation of chronic stress and fatigue is warranted to accelerate the growth of evidence.

Impaired cognitive functioning in stress-induced exhaustion disorder: a new tablet-based assessment

BACKGROUND

The adverse health effects of stress induced exhaustion disorder (SED) cause increasing concern in Western societies. This disorder is characterized by severe fatigue, decreased tolerance to further stress, and attention and memory lapses. Despite subjective complaints, individual cognitive deficits are not always detected in a clinical setting, which calls for the validation of more sensitive instruments.

AIM

The objective of this study was to investigate if a short, tablet-based serial naming task, MapCog Spectra (MCS) could be used as a marker for cognitive problems in SED.

PARTICIPANTS

The study comprised of 39 subjects (35 females, four males) with SED. Their mean age was 46,8 years (SD 10.1; range 30-60 yrs.). All participants were healthcare professionals, with a college or university degree, doctors, registered nurses, and psychologists.

METHODS

The MCS was used to assess the number of aberrant pauses during serial naming of coloured geometrical shapes. The Coding, Matrix Reasoning, Digit Span, Symbol Search of the WAIS-IV, and RUFF 2&7 tests, were administered together with a short interview.

RESULTS

Mean values were within normal reference limits for all tests, except for the MCS, which showed a significantly higher number of aberrant pauses (p < 0,001) in the SED group, compared to normal reference values. Although subjects performed within normal limits on the RUFF 2&7, a significant difference between individuals was found in the performance strategy of the participants.

CONCLUSION

Here we report that subjects with SED have performance deficits on the MCS, in terms of aberrant pause times, despite average performance on WAIS-IV tests measuring inductive reasoning, processing speed, working memory, and attention. We also demonstrate that subjects use different strategies to overcome their problems. These findings add to the growing evidence of cognitive deficits in SED and that the MCS might aid neuropsychologists in disentangling cognitive markers, important to substantiate the subjective complaints of affected individuals.

Standardized multimodal intervention for stress-induced exhaustion disorder: an open trial in a clinical setting

BACKGROUND

Long-term sick-leave due to stress-related ill-health is increasing in several economically developed countries. Even though different forms of interventions are administered in regular care for stress-related disorders, such as Stress-induced Exhaustion disorder (SED), the scientific evidence for the effectiveness of such treatments is sparse. The objective of this study was to explore changes in SED-symptoms and return-to-work-rates in a large group of SED-patients participating in a standardized Multimodal intervention (MMI) in a clinical setting.

METHOD

This open clinical trial tracked 390 patients who fulfilled the criteria for SED undergoing a 24-week MMI, including return-to-work-strategies. Before inclusion, all patients underwent a multi-professional assessment by a team of licensed physicians, licensed psychologists, and licensed physiotherapists. Self-rated questionnaires were administered before treatment, at treatment-start, mid-treatment, post-treatment, and at 12-month follow-up. Within-group change was evaluated over time with mixed-effects models. Beyond different symptoms, working time, sick-leave compensation, and adverse effects were also measured.

RESULTS

There were significant improvements in symptoms of SED, burnout, anxiety, depression, and insomnia, with large within-group effect sizes (d = 0.91-1.76), improvements that were maintained at 12-month follow-up. Furthermore, there was a significant increase in quality of life and large improvements in average working time and sick-leave compensation. Some adverse effects were reported, mainly concerning an increase in stress, anxiety, and worry.

CONCLUSION

SED-patients participating in this standardized MMI reported large symptom alleviation, increased working time and reduced sick-leave compensation, indicating a beneficial treatment. There were some adverse effects, but no more so than other psychological treatments. This study confirms previous findings that high levels of depression and anxiety decrease to sub-clinical levels during treatment, while symptoms of SED also decline, yet still persists above sub-clinical levels at 12-month follow-up. On the whole, this open clinical trial suggests that a standardized MMI, administered in a clinical setting, improves symptoms and return-to-work rates in a clinically representative SED-population.

TRIAL REGISTRATION

This study was registered on Clinicaltrials.gov 2017.12.02 (Identifier: NCT03360136 ).

Mental fatigue in stress-related exhaustion disorder: Structural brain correlates, clinical characteristics and relations with cognitive functioning

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Structural correlates of mental fatigue investigated in stress-related exhaustion.

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Patients were divided into high and low-moderate mental fatigue group.

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Patients with high mental fatigue had smaller caudate and putamen volumes.

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No significant differences in cortical thickness between the groups.

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Mental fatigue mediated the relationship between caudate volume and working memory.

Emerging evidence suggests that mental fatigue is a central component of the cognitive and clinical characteristics of stress-related exhaustion disorder (ED). Yet, the underlying mechanisms of mental fatigue in this patient group are poorly understood. The aim of this study was to investigate cortical and subcortical structural neural correlates of mental fatigue in patients with ED, and to explore the association between mental fatigue and cognitive functioning. Fifty-five patients with clinical ED diagnosis underwent magnetic resonance imaging. Mental fatigue was assessed using the Concentration subscale from the Checklist Individual Strength. Patients with high levels of mental fatigue (n = 30) had smaller caudate and putamen volumes compared to patients with low-moderate levels of mental fatigue (n = 25). No statistically significant differences in cortical thickness were observed between the groups. Mediation analysis showed that mental fatigue mediated the relationship between caudate volume and working memory; specifically, smaller caudate volume was associated with higher level of mental fatigue and mental fatigue was positively associated with working memory performance. Our findings demonstrate that the structural integrity of the striatum is of relevance for the subjective perception of mental fatigue in ED, while also highlighting the complex relationship between mental fatigue, cognitive performance and its neural underpinnings.