Emotion recognition and emotional theory of mind in chronic fatigue syndrome

Markers of limbic system damage following SARS-CoV-2 infection

Alterations of the limbic system may be present in the chronic phase of SARS-CoV-2 infection. Our aim was to study the long-term impact of this disease on limbic system-related behaviour and its associated brain functional connectivity, according to the severity of respiratory symptoms in the acute phase. To this end, we investigated the multimodal emotion recognition abilities of 105 patients from the Geneva COVID-COG Cohort 223 days on average after SARS-CoV-2 infection (diagnosed between March 2020 and May 2021), dividing them into three groups (severe, moderate or mild) according to respiratory symptom severity in the acute phase. We used multiple regressions and partial least squares correlation analyses to investigate the relationships between emotion recognition, olfaction, cognition, neuropsychiatric symptoms and functional brain networks. Six to 9 months following SARS-CoV-2 infection, moderate patients exhibited poorer recognition abilities than mild patients for expressions of fear (P = 0.03 corrected), as did severe patients for disgust (P = 0.04 corrected) and irritation (P < 0.01 corrected). In the whole cohort, these performances were associated with decreased episodic memory and anosmia, but not with depressive symptoms, anxiety or post-traumatic stress disorder. Neuroimaging revealed a positive contribution of functional connectivity, notably between the cerebellum and the default mode, somatosensory motor and salience/ventral attention networks. These results highlight the long-term consequences of SARS-Cov-2 infection on the limbic system at both the behavioural and neuroimaging levels.

Antifatigue effect of sea buckthorn seed oil on swimming fatigue in mice

The effect of sea buckthorn seed oil (SSO) on exercise-induced fatigue in mice was explored. The animals were randomly divided into a normal control group, exercise-induced fatigue group (EFG), SSO low-dose group, SSO medium-dose group, and SSO high-dose group. The mice in all the groups underwent swimming training for 10 days. Those in the treatment groups received different amounts of SSO (0.85, 1.68, and 3.35 g/kg BW [body weight]) before the exercise. All the animals were sacrificed on the last day after an exhaustive swimming test, and serum, liver, and brain specimens were collected. In the exhaustive swimming test, the swimming durations in the SSO-treated animals were longer than those in the EFG. Furthermore, SSO reduced serum lactic acid, blood urea nitrogen, and hepatic malondialdehyde levels and increased liver glycogen level, hepatic superoxide dismutase level, hypothalamic dopamine content, and glutathione peroxidase level. The SSO treatment decreased hypothalamic 5-hydroxytryptamine content, lipid hydroperoxide level, NLRP3 inflammasome, and interleukin-1β protein expression in the prefrontal cortex. Furthermore, it promoted the protein expression of nuclear factor erythroid 2-related factor 2 in the liver. SSO exhibited an excellent antifatigue effect, which may be related to its inhibition of oxidative and inflammatory injury and regulation of hypothalamic neurotransmitters. PRACTICAL APPLICATION: In the present study, the effect of sea buckthorn seed oil on fatigue in mice and its potential mechanism were explored. Taken together, the findings provide insight into the potential role of sea buckthorn seed oil in the development of antifatigue drugs.

Associations Between Psychological and Immunological Variables in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Systematic Review

Background: Little emphasis has been given to the fact that various psychological processes and behaviors in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) have neural correlates that affect-and are affected by-the immune system. The aim of this paper is to provide a systematic review of the literature on cross-sectional and longitudinal associations between psychological and immunological variables/changes in CFS/ME. Methods: The systematic literature search was conducted on Dec 10, 2020 using PubMed. Original research studies investigating associations between a predefined set of psychological and immunological variables in CFS/ME were included. Specifically, the review was focused on studies examining the following psychological variables: executive function, emotion regulation, interpersonal function, sleep, mental health, anxiety, depression, and/or other psychiatric symptoms. In terms of immunological variables, studies investigating interleukin (IL)-1, IL-2, IL-4, IL-6, tumor necrosis factor (TNF), CD4⁺, and/or CD8⁺ were included. Besides original research papers, other potentially relevant papers (e.g., literature reviews) were carefully read and reference lists were checked in order to identify any additional relevant studies. Available data was summarized in text and tables. Results: The literature search identified 897 potentially relevant papers. Ultimately, 14 studies (807 participants in total) were included in the review of which only two were longitudinal in nature. The review indicated that executive function is associated with IL-1 and IL-6, and interpersonal function is associated with IL-6 and TNF-α. Further, the available data suggested that emotion regulation is associated with IL-2 and sleep is associated with IL-1, IL-6, TNF-α, and IL-2. Interestingly, poorer emotion regulation, interpersonal function, and sleep have all been found to be associated with higher cytokine levels. Executive function has shown both positive and negative relationships with cytokines and among these psychological constructs, it is also the only one that has been found to be associated with CD4⁺ and CD8⁺ counts/percentages. Conclusions: Correlations exist between psychological and immunological variables in CFS/ME. However, there are few consistent findings and there is almost a complete lack of longitudinal studies. This review points to a gap in existing CFS/ME research and hopefully, it will inspire to the generation of innovative, psychoneuroimmunological hypotheses within the CFS/ME research field.

Differences in alexithymia and emotional awareness in exhaustion syndrome and chronic fatigue syndrome

Symptoms of Exhaustion Syndrome (ES) and Chronic Fatigue Syndrome (CFS) are overlapping and create difficulties of differential diagnosis. Empirical studies comparing ES and CFS are scarce. This study aims to investigate if there are any emotional differences between ES and CFS. This cross-sectional study compared self-reported alexithymia and observer-rated emotional awareness in patients with ES (n = 31), CFS (n = 38) and healthy controls (HC) (n = 30). Self-reported alexithymia was measured with the Toronto Alexithymia Scale-20 (TAS-20) and emotional awareness with an observer-rated performance test, the Level of Emotional Awareness Scale (LEAS). Additionally, depression and anxiety were scored by the Hospital Anxiety and Depression Scale (HADS). Results show that patients with ES expressed higher self-reported alexithymia in the TAS-20 compared to HC, but had similar emotional awareness capacity in the observer-rated performance test, the LEAS. Patients with CFS expressed more difficulties in identifying emotions compared to HCs, and performed significantly worse in the LEAS-total and spent more time completing the LEAS as compared to HC. Correlation and multiple regressions analyses revealed that depression and anxiety positively correlated with and explained part of the variances in alexithymia scores, while age and group explained the major part of the variance in LEAS. Findings of this study indicate that emotional status is different in patients with ES and CFS with respect to both self-reported alexithymia and observer-rated emotional awareness. Emotional parameters should be approached both in clinical investigation and psychotherapy for patients with ES and CFS.

Social cognition and levels of personality organization in patients with somatoform disorders: a case-control study

Social cognition and its association with level of personality organization (PO) were examined in 163 patients with severe somatoform disorders (SFDs) and 151 psychiatric (PSA) control patients. Social cognition was measured with the Social Cognition and Object Relations Scale, which assessed both affective and cognitive facets of social cognition. Levels of PO were assessed using theory-driven profiles of the Dutch Short Form of the Minnesota Multiphasic Personality Inventory (MMPI). The SFD patients exhibited impairments in the cognitive facets of social cognition but not more so than the PSA controls. The results for the affective aspects indicated that the SFD patients exhibited lower levels of emotional investment yet higher affect tone in interactions than the PSA controls. In contrast to the control group, level of PO was not associated with social cognition in SFD. Together, the results indicated that impairments in complexity of mental representations are not specific to SFD patients, yet impairments in emotional investment may be specific to SFD.