Biomarkers of Post-COVID Depression

Levels of brain-derived neurotrophic factor (BDNF) among patients with COVID-19: a systematic review and meta-analysis

Many individuals have been suffering from consistent neurological and neuropsychiatric manifestations even after the remission of coronavirus disease (COVID-19). Brain-derived neurotrophic factor (BDNF) is a protein involved in the regulation of several processes, including neuroplasticity, neurogenesis, and neuronal differentiation, and has been linked to a range of neurological and psychiatric disorders. In this study, we aimed to synthesize the available evidence on the profile of BDNF in COVID-19. A comprehensive search was done in the Web of Science core collection, Scopus, and MEDLINE (PubMed), and Embase to identify relevant studies reporting the level of BDNF in patients with COVID-19 or those suffering from long COVID. We used the NEWCASTLE-OTTAWA tool for quality assessment. We pooled the effect sizes of individual studies using the random effect model for our meta-analysis. Fifteen articles were included in the systematic review. The sample sizes ranged from 16 to 183 participants. Six studies compared the level of BDNF in COVID-19 patients with healthy controls. The pooled estimate of the standardized mean difference in BDNF level between patients with COVID-19 and healthy individuals was - 0.84 (95% CI - 1.49 to - 0.18, p = 0.01, I2 = 81%) indicating a significantly lower BDNF level in patients with COVID-19. Seven studies assessed BDNF in different severity statuses of patients with COVID-19. The pooled estimate of the standardized mean difference in BDNF level was - 0.53 (95% CI - 0.85 to - 0.21, p = 0.001, I2 = 46%), indicating a significantly lower BDNF level in patients with more severe COVID-19. Three studies evaluated BDNF levels in COVID-19 patients through different follow-up periods. Only one study assessed the BDNF levels in long COVID patients. Sensitivity analyses did not alter the significance of the association. In this study, we showed a significant dysregulation of BDNF following COVID-19 infection. These findings may support the pathogenesis behind the long-lasting effects of this disease among infected patients. PROSPERO: CRD42023413536.

Unraveling the Role of the Blood-Brain Barrier in the Pathophysiology of Depression: Recent Advances and Future Perspectives

Depression is a highly prevalent psychological disorder characterized by persistent dysphoria, psychomotor retardation, insomnia, anhedonia, suicidal ideation, and a remarkable decrease in overall well-being. Despite the prevalence of accessible antidepressant therapies, many individuals do not achieve substantial improvement. Understanding the multifactorial pathophysiology and the heterogeneous nature of the disorder could lead the way toward better outcomes. Recent findings have elucidated the substantial impact of compromised blood-brain barrier (BBB) integrity on the manifestation of depression. BBB functions as an indispensable defense mechanism, tightly overseeing the transport of molecules from the periphery to preserve the integrity of the brain parenchyma. The dysfunction of the BBB has been implicated in a multitude of neurological disorders, and its disruption and consequent brain alterations could potentially serve as important factors in the pathogenesis and progression of depression. In this review, we extensively examine the pathophysiological relevance of the BBB and delve into the specific modifications of its components that underlie the complexities of depression. A particular focus has been placed on examining the effects of peripheral inflammation on the BBB in depression and elucidating the intricate interactions between the gut, BBB, and brain. Furthermore, this review encompasses significant updates on the assessment of BBB integrity and permeability, providing a comprehensive overview of the topic. Finally, we outline the therapeutic relevance and strategies based on BBB in depression, including COVID-19-associated BBB disruption and neuropsychiatric implications. Understanding the comprehensive pathogenic cascade of depression is crucial for shaping the trajectory of future research endeavors.

Anti-stigmatizing: a collaborative autoethnography on recovery from depression

Introduction

Despite extensive research on clinical treatments for depression, there remains a significant gap in understanding of the lived experiences and recovery journeys of those with depression. This study sought to explore the recovery process through an "anti-stigmatizing" lens, emphasizing the cultural-psychological mechanisms at play and the importance of personal narratives in shaping the recovery trajectory.

Methods

Using a collaborative autoethnographic approach, this report focuses on the first author's journey of depression recovery. This research methodology allows for an in-depth exploration of subjective experiences, with a specific emphasis on the interaction between societal stigma, personal identity, and mental-health challenges.

Results

It is found that the depression-recovery experience can be divided into four stages from an anti-stigma perspective: (1) encountering the public stigma of emotions; (2) internalizing the stigma to a self-stigma; (3) "decriminalizing" the expected stigma of a "depressed" identity through diagnosis; and (4) being able to cope with and understanding the public stigma relating to depression when facing it again. Key factors that were found to contribute to recovery were self-awareness, community empowerment, and recognition and acceptance by close friends and family.

Discussion

We propose a reconceptualization of depression that incorporates a societal perspective on internalized stigma. Recovery from depression is not merely a medical process; it also pertains to how the patient frees themselves from public stigma. The results strongly indicate the need for a paradigm shift toward a more inclusive and empathetic approach to mental-health care, and we emphasize the importance of personal narratives in depression recovery.

Altered serum cytokines in patients with symptomatic disk herniation and depressive symptoms

Purpose

An increasing number of studies have indicated the important role of cytokines in the development of depressive disturbances (DD). In medically ill patients, cytokines can provoked sickness behavior, the signs of which resemble DD. This results in alterations in behavior to limit energy expenditure and redirect it to cope with particular diseases. The aim of our study was to investigate the role of pro-inflammatory IL-6, TNF-α, and IL-1β and anti-inflammatory IL-10 and TGF-β in DD observed in patients suffering from pain caused by disk herniation (DH) qualified for surgery.

Patients and methods

The intensity of DD assessed by using Beck Depression Inventory, pain intensity, and functional impairment were evaluated in 70 patients with DH who were qualified for surgery. Pro-inflammatory serum levels of TNF-α, IL-1, IL-6, anti-inflammatory TGF-β, and IL-10 were measured.

Results

Elevated serum levels of TGF-β, IL-10, and IL-6 were found in the group with moderate and severe depressive symptoms (SD) compared with the groups with mild (MD) or no depressive symptoms (ND). TGF-β levels were negatively correlated with pain intensity, as assessed using the Present Pain Intensity scale in SD. Functional impairment measured using the Oswestry Disability Index was the most advanced in SD group.

Conclusion

Results of our study can suggest association between depressive disturbances and anti-inflammatory cytokines TGF-β and IL-10. Functional impairment of SD group is more severe but serum levels of TGF-β and IL-10, which are involved in the healing processes, are increased.

[Interaction of somatic findings and psychiatric symptoms in COVID-19. A scoping review]

An infection with SARS-CoV‑2 can affect the central nervous system, leading to neurological as well as psychiatric symptoms. In this respect, mechanisms of inflammation seem to be of much greater importance than the virus itself. This paper deals with the possible contributions of organic changes to psychiatric symptomatology and deals especially with delirium, cognitive symptoms, depression, anxiety, posttraumatic stress disorder and psychosis. Processes of neuroinflammation with infection of capillary endothelial cells and activation of microglia and astrocytes releasing high amounts of cytokines seem to be of key importance in all kinds of disturbances. They can lead to damage in grey and white matter, impairment of cerebral metabolism and loss of connectivity. Such neuroimmunological processes have been described as a organic basis for many psychiatric disorders, as affective disorders, psychoses and dementia. As the activation of the glia cells can persist for a long time after the offending agent has been cleared, this can contribute to long term sequalae of the infection.

Prevalence of depression, stress and suicide tendency among individuals with long COVID and determinants: a protocol of a systematic review and meta-analysis

BACKGROUND

It is well known that the COVID-19 pandemic has had a devastating impact on mental health, especially among individuals with long COVID. This systematic review and meta-analysis aims to investigate the prevalence of depression, stress and suicide tendencies among individuals with long COVID, as well as to explore the factors that contribute to these conditions.

METHODS AND ANALYSIS

A comprehensive review of literature will be conducted in various databases of including PubMed, including Medline, Embase, PsycINFO, CINAHL and Cochrane Library. The studies to be included in this review will be published in the English language, and the time frame of included studies will be from the date of inception of COVID-19 until 30 December 2023. Two independent reviewers will identify studies for inclusion based on a screening questionnaire, and the JBI standardised critical appraisal checklist for studies reporting prevalence data will be used to assess the methodological quality. The strength of the body of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. To analyse the data, a robust Bayesian approach will be applied using the STATA software package (V.14; STATA) and JASP software. The findings of this systematic review and meta-analysis will provide valuable insights into the prevalence of depression, stress and suicide tendencies among individuals with long COVID, as well as the factors that contribute to these conditions.

ETHICS AND DISSEMINATION

There is no research ethics board approval required. The dissemination plan is to publish results in a peer-reviewed academic journal.

PROSPERO REGISTRATION NUMBER

CRD42022346858.

[A clinical case of the new-onset bipolar affective disorder in the postcovid period]

A large number of people who have had COVID-19 have developed mental symptoms and mood disorders. Anxiety and depression prevail among affective pathology. Evidence is accumulating that the Sars-CoV-2 virus can induce mania or hypomania in people with no personal psychopathological history. Some clinical, anamnestic and paraclinical patterns of new-onset mania and hypomania have been found. In cases of severe manic symptoms, it is possible to quickly assume the occurrence of bipolar affective disorder. The predominance of depressive and anxiety syndromes in the long-term disease and the presence of vivid vegetative symptoms can mask brief and syndromally incomplete episodes of hypomania, which distorts the understanding of the disease as a bipolar disorder. This article presents such a clinical case of the occurrence of bipolar affective disorder in a patient who had COVID-19 with an asymptomatic course. Approaches to rational diagnosis and treatment are discussed.

Attention deficits and depressive symptoms improve differentially after rehabilitation of post-COVID condition - A prospective cohort study

BACKGROUND

Depressive and cognitive symptoms like fatigue, loss of energy or sleep disorders characterise the post-COVID condition. Post-COVID psychosomatic rehabilitation should focus on both symptom groups. The current prospective cohort study addresses the change in these symptoms in the context of a psychosomatic rehabilitation.

METHOD

N = 80 patients with post-COVID symptoms underwent psychological testing on admission and discharge: PHQ-9 questionnaire for depression, TAP - test battery for the attention test with the sub-tests working memory, sustained attention, divided attention and alertness. Sample characteristics, including health-related and work-related parameters, the general symptom load and the course of symptoms during the five weeks of rehabilitation were evaluated.

RESULTS

On admission, the PHQ-9 indicated the presence of depressive symptoms in post-COVID patients (PHQ-9 = 15.15 ± 5.11). Over the course of rehabilitation, the depressive symptoms decreased to a sub-clinical level (PHQ-9 = 8.80 ± 4.61), suggesting a strong effect of post-COVID inpatient rehabilitation (Cohen's d = 1.57). At the same time, post-COVID patients showed clinically relevant impairments in attention and working memory that persisted throughout the rehabilitation period despite multimodal post-COVID treatment.

CONCLUSION

Over the course of post-COVID rehabilitation, depressive symptoms appear to be significantly reduced. With regard to cognitive impairment, a comparable effect within the short period of 5 weeks is not evident. Our results suggest the need for specific treatment of persistent neuropsychological deficits following post-COVID rehabilitation.

Post-COVID-19 depression and serum interleukin 6 levels: A systematic review and meta-analysis of COVID-19 convalescents with and without depression

OBJECTIVES

Depression is among the psychiatric sequelae of COVID-19, affecting more than 20% of the convalescents. Its underlying pathophysiology remains unclear. Interleukin 6 (IL-6), a pro-inflammatory cytokine, plays a critical role in the COVID-19-associated cytokine storm, has been implicated in depressive disorders, and may thus be involved in post-COVID-19 depression.

METHODS

PubMed, Scopus, Embase, and Web of Science were systematically searched for relevant studies assessing peripheral IL-6 levels in convalescents who developed depression after COVID-19 vs. convalescents who did not.

RESULTS

Five studies were included in our systematic review, and four entered the meta-analysis. The meta-analysis revealed that post-COVID people with de novo depression did not have statistically significant differences in IL-6 levels compared to those without depression (standardised mean difference (SMD) = 0.09, 95% confidence interval (CI) = -0.35, 0.54, p-value = 0.68).

CONCLUSIONS

Although convalescents with depression did not have significantly higher IL-6 levels than convalescents without depression, the results should be interpreted considering the limited sample size and the low power of the included studies.

A Review Article on Exercise Intolerance in Long COVID: Unmasking the Causes and Optimizing Treatment Strategies

There is a growing body of research on SARS-CoV-2 (PASC), previously known as the post-COVID syndrome, a chronic condition characterized by symptoms that persist after SARS-CoV-2 infection. Among these symptoms, feelings of physical exhaustion and prolonged fatigue are particularly prevalent and can significantly impact patients' quality of life. These symptoms are associated with reduced overall physical capacity, decreased daily physical activity, malaise after intense training, and intolerance to physical activity (IFA). IFA, described as a reduced ability to perform physical activities typical for the patient's age, can often lead to a sedentary lifestyle. Prolonged physical inactivity can cause deterioration in the overall physical condition and disrupt mitochondrial function, triggering a vicious cycle of gradual symptom worsening. The underlying causes of PASC remain unclear; however, several biochemical mechanisms have been discussed to explain the body's energy depletion, and a multidisciplinary approach that combines physical and cognitive rehabilitation and lifestyle interventions such as exercise and diet modifications has been suggested to improve the overall health and well-being of PASC patients. This critical review aims to review the existing research on the possible causes and links among chronic fatigue, reduced physical activity, and exercise intolerance in patients with PASC. Further research into the underlying causes and treatment of PASC and the importance of developing individualized treatment is needed to address each patient's unique health requirements.

Post COVID-19 complications and follow up biomarkers

Millions of people were infected by the coronavirus disease (COVID-19) epidemic, which left a huge burden on the care of post COVID-19 survivors around the globe. The self-reported COVID-19 symptoms were experienced by an estimated 1.3 million people in the United Kingdom (2% of the population), and these symptoms persisted for about 4 weeks from the beginning of the infection. The symptoms most frequently reported were exhaustion, shortness of breath, muscular discomfort, joint pain, headache, cough, chest pain, cognitive impairment, memory loss, anxiety, sleep difficulties, diarrhea, and a decreased sense of smell and taste in post-COVID-19 affected people. The post COVID-19 complications were frequently related to the respiratory, cardiac, nervous, psychological and musculoskeletal systems. The lungs, liver, kidneys, heart, brain and other organs had been impaired by hypoxia and inflammation in post COVID-19 individuals. The upregulation of substance "P" (SP) and various cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 1 beta (IL-1β), angiotensin-converting enzyme 2 (ACE2) and chemokine C-C motif ligand 3 (CCL3) has muddled respiratory, cardiac, neuropsychiatric, dermatological, endocrine, musculoskeletal, gastrointestinal, renal and genitourinary complications in post COVID-19 people. To prevent these complications from worsening, it was therefore important to study how these biomarkers were upregulated and block their receptors.

Self-Reported Mental Health Measures of Incoming Collegiate Student-Athletes With a History of COVID-19

BACKGROUND

People with a history of COVID-19 may experience persistent neuropsychological disruptions such as lower satisfaction with life, depression, and anxiety. Although student-athletes are at low risk for severe COVID-19 complications, the effect of COVID-19 on mental health has not been elucidated.

OBJECTIVE

To compare patient-reported mental health outcomes for incoming collegiate athletes with (COVID+) or without (COVID-) a history of COVID-19.

DESIGN

Case-control study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 178 student-athletes, consisting of 79 in the COVID+ group (44.3%; age = 18.90 ± 0.16 years) and 99 in the COVID- group (55.6%; age = 18.95 ± 0.16 years).

MAIN OUTCOME MEASURE(S)

Participants completed the Satisfaction With Life Scale (SWLS), the Hospital Anxiety and Depression Scale (HADS), and the State-Trait Anxiety Inventory (STAI). Unadjusted 1-way analyses of variance were conducted across all patient-reported outcomes. Analyses of covariance were calculated to determine the interaction of COVID-19 group, sex, and race and ethnicity on outcomes. Post hoc Bonferroni testing was performed to identify specific differences between groups. A χ2 analysis was computed to compare the number of athletes in each group who met the standard clinical cut points.

RESULTS

We observed a between-groups difference for HADS depression (P = .047), whereby athletes in the COVID+ group had higher ratings (2.86 ± 0.26). We found group differences for the SWLS (P = .02), HADS anxiety (P = .003), and STAI state anxiety (P = .01) such that all scores were higher for the COVID+ group in the adjusted model. Post hoc testing revealed that female student-athletes in the COVID+ group had worse HADS anxiety (P = .01) and STAI trait anxiety (P = .002) scores than individuals in all other groups. We did not demonstrate differences between groups in the percentage of responses below established diagnostic thresholds.

CONCLUSIONS

Incoming collegiate student-athletes who reported a previous COVID-19 diagnosis displayed higher depression scores, suggesting that clinicians may need to provide appropriate identification and referral for mental health conditions. However, we were encouraged that most participants, regardless of a history of COVID-19 diagnosis, had mental health scores that did not exceed established diagnostic threshold values.

Treatment of ankylosing spondylitis with TNFα inhibitors does not affect serum levels of tryptophan metabolites

The imbalance between the kynurenine and serotonin pathways can have serious consequences, e.g., depression. One of the factors leading to the imbalance between the pathways of tryptophan metabolism is inflammation. The aim of our study was to assess the impact of treatment with tumor necrosis factor-alpha (TNFα)-inhibitors on tryptophan metabolism in patients with ankylosing spondylitis (AS). Forty patients with AS (twenty-eight males, twelve females; mean age 40 ± 11 years), qualified to receive anti-TNF-α treatment, were prospectively assessed. As a control group, 20 healthy volunteers (7 males and 13 females, mean age 38 ± 5 years) were recruited from the general population. Patients underwent full clinical and biochemical assessment before and after 6 months of therapy. Disease activity was assessed by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). The presence of depressive disorders was assessed with Beck's Depression Inventory (BDI) scale. Serum concentrations of tryptophan, serotonin, kynurenine, and quinolinic acid were measured. The predominance of the kynurenine pathway in AS patients (compared to the control group) was demonstrated (p < 0.001). Surprisingly, no significant changes in serum levels of tryptophan and its metabolites in AS patients after treatment were found, despite clinical improvement. Moreover, the components of tryptophan metabolism did not correlate significantly with the clinical activity of AS, depression nor laboratory inflammatory markers. Probably some other factors influence the pathways of tryptophan metabolism in patients with ankylosing spondylitis.

Potential Inflammatory Biomarkers for Major Depressive Disorder Related to Suicidal Behaviors: A Systematic Review

Major depressive disorder (MDD) is a highly prevalent psychiatric condition affecting an estimated 280 million individuals globally. Despite the occurrence of suicidal behaviors across various psychiatric conditions, MDD is distinctly associated with the highest risk of suicide attempts and death within this population. In this study, we focused on MDD to identify potential inflammatory biomarkers associated with suicidal risk, given the relationship between depressive states and suicidal ideation. Articles published before June 2023 were searched in PubMed, Embase, Web of Science, and the Cochrane Library to identify all relevant studies reporting blood inflammatory biomarkers in patients with MDD with suicide-related behaviors. Of 571 articles, 24 were included in this study. Overall, 43 significant biomarkers associated with MDD and suicide-related behaviors were identified. Our study provided compelling evidence of significant alterations in peripheral inflammatory factors in MDD patients with suicide-related behaviors, demonstrating the potential roles of interleukin (IL)-1β, IL-6, C-reactive protein, C-C motif chemokine ligand 2, and tumor necrosis factor-α as biomarkers. These findings underscore the intricate relationship between the inflammatory processes of these biomarkers and their interactions in MDD with suicidal risk.

Long-lasting cognitive effects of COVID-19: is there a role of BDNF?

Coronavirus disease 2019 (COVID-19) affects numerous systems of the body during the illness, and there have been long-lasting effects. BDNF plays an important role in synaptic plasticity and synaptic communication. According to the inclusion and exclusion criteria, 54 patients who had COVID-19 infection participated in this study. Thirty-six age-, sex-, body mass index (BMI)-, education level- and smoking status-matched healthy controls were included in the present study. All participants were individually administered the Stroop test and Visual Aural Digit Span Test Form B (VADS-B). Serum BDNF levels were measured by ELISA. Stroop test word reading spontaneous correction number and reading time, word color saying wrong number, spontaneous correction number and reading time, box color speaking spontaneous correction number and reading time, Stroop interference and speed factor duration were significantly higher in the COVID-19 group than in the control group. All scores of the VADS-B test were found to be significantly lower in the COVID-19 group. The mean serum BDNF levels were found to be 10.9 ± 6.9 ng/ml in the COVID-19 group and 12.8 ± 6.4 ng/ml in the healthy control group. Two-way ANOVA showed that the serum mean BDNF level was significantly lower in the COVID-19 group than in the control group. Gender had a significant effect on BDNF levels (F = 12.21; p = 0.008). The present study is the first to demonstrate the association between the role of serum BDNF and cognitive decline in patients with COVID-19 infection. Additionally, there is a significant role of male gender in terms of lower BDNF level and cognitive decline.

The Relationship Between COVID-19 and the Development of Depression: Implications on Mental Health

Initially, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease-2019 (COVID-19), was predominantly considered to primarily affect the respiratory system. However, later studies revealed that it also affects brain function through its ability to bind to the angiotensin-converting enzyme type 2 (ACE2) receptors expressed on neural cells. Our study involved a comprehensive review of literature aiming to investigate the relationship between COVID-19 and the development of depression. Our analysis shows a connection between these 2 conditions, as a consequence of the inflammatory response in the nervous system to the COVID-19 virus and the psychophysiological effects of the pandemic. In COVID-19 patients, depression can arise either due to the direct viral infection of the brain or as a result of an indirect immune response triggering neuroinflammation after a cytokine storm. The resulting depression can be treated with non-pharmacological therapies such as psychotherapy, antidepressant medications, or a combination of these treatments depending on the severity of the symptoms.

Inflammatory and mental health sequelae of COVID-19

The COVID-19 pandemic has caused significant negative consequences to mental health. Increased inflammatory factors and neuropsychiatric symptoms, such as cognitive impairment ("brain fog"), depression, and anxiety are associated with long COVID [post-acute sequelae of SARS-CoV-2 infection (PASC), termed neuro-PASC]. The present study sought to examine the role of inflammatory factors as predictors of neuropsychiatric symptom severity in the context of COVID-19. Adults (n = 52) who tested negative or positive for COVID-19 were asked to complete self-report questionnaires and to provide blood samples for multiplex immunoassays. Participants who tested negative for COVID-19 were assessed at baseline and at a follow-up study visit (∼4 weeks later). Individuals without COVID-19 reported significantly lower PHQ-4 scores at the follow-up visit, as compared to baseline (p = 0.03; 95% CI-1.67 to -0.084). Individuals who tested positive for COVID-19 and experienced neuro-PASC had PHQ-4 scores in the moderate range. The majority of people with neuro-PASC reported experiencing brain fog (70% vs. 30%). Those with more severe COVID-19 had significantly higher PHQ-4 scores, as compared to those with mild disease (p = 0.008; 95% CI 1.32 to 7.97). Changes in neuropsychiatric symptom severity were accompanied by alterations in immune factors, particularly monokine induced by gamma interferon (IFN-γ) (MIG, a. k.a. CXCL9). These findings add to the growing evidence supporting the usefulness of circulating MIG levels as a biomarker reflecting IFN-γ production, which is important because individuals with neuro-PASC have elevated IFN-γ responses to internal SARS-CoV-2 proteins.

Shared biological mechanisms of depression and obesity: focus on adipokines and lipokines

Depression and obesity are both common disorders currently affecting public health, frequently occurring simultaneously within individuals, and the relationship between these disorders is bidirectional. The association between obesity and depression is highly co-morbid and tends to significantly exacerbate metabolic and related depressive symptoms. However, the neural mechanism under the mutual control of obesity and depression is largely inscrutable. This review focuses particularly on alterations in systems that may mechanistically explain the in vivo homeostatic regulation of the obesity and depression link, such as immune-inflammatory activation, gut microbiota, neuroplasticity, HPA axis dysregulation as well as neuroendocrine regulators of energy metabolism including adipocytokines and lipokines. In addition, the review summarizes potential and future treatments for obesity and depression and raises several questions that need to be answered in future research. This review will provide a comprehensive description and localization of the biological connection between obesity and depression to better understand the co-morbidity of obesity and depression.

Promising Markers of Inflammatory and Gut Dysbiosis in Patients with Post-COVID-19 Syndrome

Post-COVID-19 syndrome is a complex of different symptoms, which results in a multisystemic impairment after the suffering from COVID-19 infection. The aim of the study was to reveal the clinical, laboratory, and gut disorders in patients with post-COVID-19 syndrome (n = 39) before and after taking part in the 14-day complex program of rehabilitation. A complete blood count, coagulation test, blood chemistry, biomarkers, and metabolites in serum samples, and gut dysbiosis were revealed in patients on the day of admission and after 14-day rehabilitation, in comparison with the variables of healthy volunteers (n = 48) or with reference ranges. On the day of discharge, patients noted an improvement in respiratory function, general well-being, and mood. At the same time, the levels of some metabolic (4-hydroxybenzoic, succinic, fumaric acids) and inflammatory (interleukin-6) variables, which were increased on admission, did not reach the level of healthy people during the rehabilitation program. Taxonomy disbalance was observed in patients' feces, namely, a high level of total bacterial mass, a decrease in the number of Lactobacillus spp., and an increase in pro-inflammatory microorganisms. The authors suggest that the post-COVID-19 rehabilitation program should be personalized, considering the patient's state together with not only the baseline levels of biomarkers, but also with the individual taxonomy of the gut microbiota.

Effects of COVID-19 pandemic on depression in patients with schizophrenia: A mini-review of the current evidence

BACKGROUND

Since the emergence of COVID-19, there have been concerns about the psychological effects of the pandemic on people's mental health around the world. People with psychotic disorders like schizophrenia (SCZ) may be more prone to develop mood disorders during the lockdowns due to their limited access to healthcare, reduced social support, and probable cognitive impairment.

METHODS

We conducted a systematic search on PubMed and Scopus to explore the effects of the pandemic on depressive symptoms in individuals with SCZ. A total of 12 studies were included.

RESULTS

Overall, studies suggested higher depression rates in patients with SCZ compared to healthy controls. Isolation due to the COVID-19 infection emerged as a risk factor for the development of depressive symptoms. However, results regarding the longitudinal changes of depression in SCZ patients during the lockdowns were inconsistent.

LIMITATIONS

The small sample sizes of studies, different depression scales and stages of the lockdowns, as well as the different government policies and restriction levels across the countries limit the conclusions of the present review.

CONCLUSIONS

Our review suggests an increased probability of depression in patients with SCZ during the pandemic. Identifying the risk factors for developing depression in this population helps find new, suitable approaches to address patients' needs and lower the adverse psychological effects of the pandemic.

Inflammation and severity of depressive symptoms in physically active individuals after COVID-19 – An exploratory immunopsychological study investigating the effect of inflammation on depressive symptom severity

Background

SARS-CoV-2 infection is a risk factor for the development of depressive symptoms such as lack of energy, loss of interest, and depressed mood. Inflammatory processes might underline this association. The aim of this study was to investigate the association between inflammatory markers and the severity of depression after SARS-CoV-2 infection, and the predictive effect of inflammatory markers on the severity of depressive symptoms. Lifestyle factors and lifestyle-related diseases can influence inflammation and depressive symptoms. As these lifestyle factors and lifestyle-related diseases are less common in physically active individuals, they are a suitable population for investigating this research question.

Methods

We investigated 61 at least moderate physically active individuals on average ∼6 months (SD = 4.22, range = 0.5–19 months) after SARS-CoV-2 infection (t₀) and performed a follow-up after 3 months (t₁). Depressive symptoms and biomarkers of inflammation (interleukin [IL]-1β, IL-8, IL-10, Ferritin, Lipopolysaccharide-binding-protein [LBP], neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], lymphocyte-to-monocyte ratio [LMR]) and kynurenine [KYN] were measured at both time points. Concentrations of inflammatory markers at t₀ were used to predict the severity of depressive symptoms at t₀ and t₁.

Results

Concentrations of KYN were negatively related to the severity of depressive symptoms at t_0. Concentrations of LMR predicted higher depressive symptoms at t₀ as well as at t₁. Furthermore, individuals with lower concentrations of LBP at t₀ showed a higher severity of depressive symptoms at t₁. No correlation was found between severity of depressive symptoms and IL1β, IL-8, IL-10, ferritin, NLR, and PLR at both time points.

Conclusions

KYN, LBP and LMR might be useful as a predictive factor of depressive symptoms in physically active individuals after SARS-CoV-2 infection. While the results for KYN confirm the current scientific evidence, our results highlight the importance of the innovative inflammatory markers LMR and LBP. LMR and LBP might be interesting targets for predicting the development of depressive symptoms in SARS-CoV-2 infected populations and should be further investigated in future studies.

Interaction effects between sleep disorders and depression on heart failure

BACKGROUND

Sleep disorders and depression were recognized as independent risk factors for heart failure, whether their interaction effects also correlated with the risk of heart failure remains elusive. This study was to explore the interaction effects between sleep disorders and depression on the risk of heart failure.

METHODS

This was a cross-sectional study that included data from 39,636 participants in the National Health and Nutritional Examination Survey (NHANES) database. Poisson regression model was applied to evaluate the associations of depression or sleep disorders with heart failure. The relative excess risk of interaction (RERI), attributable proportion of interaction (API) and synergy index (SI) were used to measure whether the interaction effects between depression and sleep disorders on heart failure was statistically significant.

RESULTS

The risk of heart failure was increased in people with sleep disorders [risk ratio (RR) = 1.92, 95% confidence interval (CI): 1.68-2.19) after adjusting for confounders including age, gender, body mass index (BMI), race, marital status, education level, annual family income, drinking history, smoking history, diabetes, hypertension and stroke. The risk of heart failure was elevated in patients with depression after adjusting for confounders (RR = 1.96, 95%CI: 1.65-2.33). Patients with depression and sleep disorders were associated with increased risk of heart failure after adjusting for confounders (RR = 2.76, 95%CI: 2.23-3.42). The CIs of interactive indexes RERI was -0.42 (95%CI: -1.23-0.39), and API was -0.15 (95%CI: -0.46-0.16), which included 0. The CI of interactive indexes SI was 0.81 (95%CI: 0.54-1.21), which contained 1.

CONCLUSION

Depression and sleep disorders were independent risk factors for heart failure but the interaction effects between depression and sleep disorders on the occurrence of heart failure were not statistically different.

Stress levels, psychological symptoms, and C-reactive protein levels in COVID-19: A cross-sectional study

BACKGROUND

Although many studies have pointed out a possible relationship between COVID-19 and the presence of psychiatric disorders, the majority of the studies have significant limitations. This study investigates the influence of COVID-19 infection on mental health.

METHODS

This cross-sectional study included an age- and sex-matched sample of adult individuals positive (cases) or negative (controls) for COVID-19. We evaluated the presence of psychiatric conditions and C-reactive protein (CRP).

RESULTS

Findings showed greater severity of depressive symptoms, higher levels of stress, and greater CRP in cases. The severity of depressive and insomnia symptoms, as well as the CRP were more remarkable in individuals with moderate/severe COVID-19. We found a positive correlation between stress and severity of anxiety, depression, and insomnia in individuals with or without COVID-19. There was a positive correlation between CRP levels and severity of depressive symptoms in cases and controls, and a positive correlation between CRP levels and the severity of anxiety symptoms and stress levels only in individuals with COVID-19. Individuals with COVID-19 and depression had greater CRP than those with COVID-19 without current major depressive disorder.

LIMITATIONS

We cannot infer causality because this is a cross-sectional study, and the majority of COVID-19 sample was asymptomatic or had mild symptoms, which may limit the generalizability of our findings for moderate/severe cases.

CONCLUSIONS

Individuals with COVID-19 showed greater severity of psychological symptoms, which may impact on the development of psychiatric disorders in the future. CPR seem to be a promising biomarker for earlier detection of post-COVID depression.

Beyond monoamines: I. Novel targets and radiotracers for Positron emission tomography imaging in psychiatric disorders

With the emergence of positron emission tomography (PET) in the late 1970s, psychiatry had access to a tool capable of non-invasive assessment of human brain function. Early applications in psychiatry focused on identifying characteristic brain blood flow and metabolic derangements using radiotracers such as [¹⁵ O]H₂ O and [¹⁸ F]FDG. Despite the success of these techniques, it became apparent that more specific probes were needed to understand the neurochemical bases of psychiatric disorders. The first neurochemical PET imaging probes targeted sites of action of neuroleptic (dopamine D₂ receptors) and psychoactive (serotonin receptors) drugs. Based on the centrality of monoamine dysfunction in psychiatric disorders and the measured success of monoamine-enhancing drugs in treating them, the next 30 years witnessed the development of an armamentarium of PET radiopharmaceuticals and imaging methodologies for studying monoamines. Continued development of monoamine-enhancing drugs over this time however was less successful, realizing only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely paralleled drug development priorities resulting in the development of new PET imaging agents for non-monoamine targets. Part one of this review will briefly survey novel PET imaging targets with relevance to the field of psychiatry, which include the metabotropic glutamate receptor type 5 (mGluR5), purinergic P₂ X₇ receptor, type 1 cannabinoid receptor (CB₁ ), phosphodiesterase 10A (PDE10A), and describe radiotracers developed for these and other targets that have matured to human subject investigations. Current limitations of the targets and techniques will also be discussed.

C-Reactive Protein (CRP): A Potent Inflammation Biomarker in Psychiatric Disorders

An increasing number of studies have investigated the role of inflammation in psychiatric disorders, by demonstrating how an altered/dysfunctional immunological and inflammatory system may underpin a psychiatric condition. Particularly, several studies specifically investigated the role of a neuroinflammatory biomarker, named C-reactive protein (CRP), in psychiatric disorders. Overall, even though scientific literature so far published still does not appear definitive, CRP is more likely reported to be elevated in several psychiatric disorders, including schizophrenia, mood disorders, anxiety disorders and post-traumatic stress disorder. Moreover, a low-grade inflammation (CRP >3 mg/L) has been more likely observed in a subgroup of patients affected with a more severe psychopathological symptomatology, more treatment resistance and worst clinical mental illness course, strengthening the hypothesis of the need for a different clinical and prognostic characterization based on this concomitant neuroinflammatory predisposition. However, even though further research studies are needed to confirm this preliminary evidence, CRP may represent a potential clinical routine biomarker which could be integrated in the clinical routine practice to better characterize clinical picture and course as well as address clinicians towards a personalized treatment.

The Potential Effect of Royal Jelly on Biomarkers Related to COVID-19 Infection and Severe Progression

Royal jelly is a yellowish to white gel-like substance that is known as a "superfood" and consumed by queen bees. There are certain compounds in royal jelly considered to have health-promoting properties, including 10-hydroxy-2-decenoic acid and major royal jelly proteins. Royal jelly has beneficial effects on some disorders such as cardiovascular disease, dyslipidemia, multiple sclerosis, and diabetes. Antiviral, anti-inflammatory, antibacterial, antitumor, and immunomodulatory properties have been ascribed to this substance. This chapter describes the effects of royal jelly on COVID-19 disease.

[Mental disorders associated with acute COVID-19: clinical picture, therapy approaches]

BACKGROUND

The purpose is to study the structure of clinical manifestations of mental disorders in the acute period of COVID-19 among patients, who were hospitalized with a new coronavirus infection and their relations with the severity of the immune response, to assess the efficacy and safety profile of the spectrum of used psychopharmacotherapy.

MATERIAL AND METHODS

A study was conducted of patients, hospitalized to the department of infectious diseases and repurposed for COVID-19 clinical departments with a diagnosis of COVID-19 (compliance with the criteria for ICD-10: U07.1) from September 2020 to March 2021. Study design: single center opened retrospective cohort study. The main group is consisted of 72 patients, average age - 71 [56.0; 81.0] years, the part of women - 64.0%. The control group (n=2221) was formed from those hospitalized in the same period with a diagnosis of U07.1 without mental disorders during the hospitalization period, average age 62 [51.0; 72.0] years, the part of women - 48.7%. Mental disorders were diagnosed in accordance to ICD-10 criteria, the following peripheral markers of inflammation, that were evaluated: neutrophils, lymphocytes, platelets, ESR, C-reactive protein, interleukin; also coagulogram indicators: APTT, fibrinogen, prothrombin time, D-dimers.

RESULTS

In the following range of mental disorders were identified: a depressive episode (ICD-10 F32) by 31 patients, by 22 - a disorder of adaptive reactions (ICD-10 F43.2), by 5 - delirium not caused by alcohol or other psychoactive substances (ICD-10 F05), by 14 - mild cognitive impairment caused by damage and disfunction of the brain or somatic diseases (ICD-10 F06.7). In comparison with the control group, these patients showed a statistically significant (p<0.001) increasing the level of inflammatory markers (CRP, IL-6) and changes in the coagulogram. and anxiolytic drugs were used most often. Regarding psychopharmacotherapy, drugs from the group of atypical antipsychotics - quetiapine was prescribed in 44% patients in average dose 62.5 mg per day, and Melatonin receptor type 1 and 2 agonist and antagonists of serotonin 5-HT2C receptors: agomelatine was prescribed in 11% patients in average dose 25 mg per gay.

CONCLUSION

The results of the study confirm the heterogeneity of the structure of mental disorders in the acute form of coronavirus infection, revealing the relations between the clinical picture and laboratory parameters of the immune response to systemic inflammation. Recommendations are given for the choice of psychopharmacotherapy, in conformity with the peculiarities of pharmacokinetics and interaction with somatotropic therapy.

Role of neuroinflammation mediated potential alterations in adult neurogenesis as a factor for neuropsychiatric symptoms in Post-Acute COVID-19 syndrome-A narrative review

Persistence of symptoms beyond the initial 3 to 4 weeks after infection is defined as post-acute COVID-19 syndrome (PACS). A wide range of neuropsychiatric symptoms like anxiety, depression, post-traumatic stress disorder, sleep disorders and cognitive disturbances have been observed in PACS. The review was conducted based on PRISMA-S guidelines for literature search strategy for systematic reviews. A cytokine storm in COVID-19 may cause a breach in the blood brain barrier leading to cytokine and SARS-CoV-2 entry into the brain. This triggers an immune response in the brain by activating microglia, astrocytes, and other immune cells leading to neuroinflammation. Various inflammatory biomarkers like inflammatory cytokines, chemokines, acute phase proteins and adhesion molecules have been implicated in psychiatric disorders and play a major role in the precipitation of neuropsychiatric symptoms. Impaired adult neurogenesis has been linked with a variety of disorders like depression, anxiety, cognitive decline, and dementia. Persistence of neuroinflammation was observed in COVID-19 survivors 3 months after recovery. Chronic neuroinflammation alters adult neurogenesis with pro-inflammatory cytokines supressing anti-inflammatory cytokines and chemokines favouring adult neurogenesis. Based on the prevalence of neuropsychiatric symptoms/disorders in PACS, there is more possibility for a potential impairment in adult neurogenesis in COVID-19 survivors. This narrative review aims to discuss the various neuroinflammatory processes during PACS and its effect on adult neurogenesis.

Is SARS-CoV-2 a Risk Factor of Bipolar Disorder?-A Narrative Review

For 2.5 years we have been facing the coronavirus disease (COVID-19) and its health, social and economic effects. One of its known consequences is the development of neuropsychiatric diseases such as anxiety and depression. However, reports of manic episodes related to COVID-19 have emerged. Mania is an integral part of the debilitating illness-bipolar disorder (BD). Due to its devastating effects, it is therefore important to establish whether SARS-CoV-2 infection is a causative agent of this severe mental disorder. In this narrative review, we discuss the similarities between the disorders caused by SARS-CoV-2 and those found in patients with BD, and we also try to answer the question of whether SARS-CoV-2 infection may be a risk factor for the development of this affective disorder. Our observation shows that disorders in COVID-19 showing the greatest similarity to those in BD are cytokine disorders, tryptophan metabolism, sleep disorders and structural changes in the central nervous system (CNS). These changes, especially intensified in severe infections, may be a trigger for the development of BD in particularly vulnerable people, e.g., with family history, or cause an acute episode in patients with a pre-existing BD.

Long COVID: a narrative review of the clinical aftermaths of COVID-19 with a focus on the putative pathophysiology and aspects of physical activity

The pandemic coronavirus disease 2019 (COVID-19) can cause multi-systemic symptoms that can persist beyond the acute symptomatic phase. The post-acute sequelae of COVID-19 (PASC), also referred to as long COVID, describe the persistence of symptoms and/or long-term complications beyond 4 weeks from the onset of the acute symptoms and are estimated to affect at least 20% of the individuals infected with SARS-CoV-2 regardless of their acute disease severity. The multi-faceted clinical picture of long COVID encompasses a plethora of undulating clinical manifestations impacting various body systems such as fatigue, headache, attention disorder, hair loss and exercise intolerance. The physiological response to exercise testing is characterized by a reduced aerobic capacity, cardiocirculatory limitations, dysfunctional breathing patterns and an impaired ability to extract and use oxygen. Still, to this day, the causative pathophysiological mechanisms of long COVID remain to be elucidated, with long-term organ damage, immune system dysregulation and endotheliopathy being among the hypotheses discussed. Likewise, there is still a paucity of treatment options and evidence-based strategies for the management of the symptoms. In sum, this review explores different aspects of long COVID and maps the literature on what is known about its clinical manifestations, potential pathophysiological mechanisms, and treatment options.

Online Yoga and Ayurveda Intervention as Tertiary Prevention of Psychological Comorbidities in COVID-19 Survivors: A Randomized Controlled Trial

Background and Purpose

About 56% of symptomatic COVID-19 survivors have been found with neuropsychological comorbidities, such as depression, anxiety, posttraumatic stress disorders (PTSD), and impaired quality of life (QoL). Alongside, antimicrobial, anti-inflammatory, neuroprotective, regenerative, immunomodulatory, cardio-pulmonary health promotive, and psychological benefits of yogic and Ayurvedic intervention are well documented. Therefore, this study aimed to assess the effect of online Yoga (OYI) and Yoga cum Ayurveda intervention (OYAI) on COVID-19-induced depression, anxiety, PTSD, and poor QoL.

Method

Seventy-two participants (males/females: 33/26) with at least a 3-month back history of symptomatic COVID-19 infection and age (mean ± SD: 32.33 ± 9.9 and 33.04 ± 12.9 for males and females, respectively) were recruited from Patanjali Ayurveda Hospital, Haridwar, India, and All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India, before random allocation into an equal-sized control group (CG), Yoga group (YG) and Yoga cum concoction (YCG) group. Split-plot analysis of variance and Kruskal–Wallis tests with Bonferroni adjusted post hoc comparisons were computed for normal and nonnormal data using IBM SPSS (25th Version, SPSS South Asia Private Limited, Bangalore, India).

Results

Both the treatments—the 30-day OYI and OYAI, significantly improved depression ( P < .002, ES: -0.99 and P < .001, ES: -2.11), anxiety ( P < .001, ES: -1.32 and -1.89), PTSD ( P < .001, ES: -1.8 and -1.83) and QoL related constructs ( P < .001, ES: 0.63 and 0.76; 0.71 and 0.93 for each OYI and OYAI versus general health and physical health; P < .001, ES: 0.65 for OYAI versus psychological health; and P < .003, ES: 0.54 for OYI versus environment) of the participants compared to the controls.

Conclusion

OYAI may better ameliorate COVID-19-induced psychological comorbidities than OYI with no adverse effects.

Effects of vaccination, new SARS-CoV-2 variants and reinfections on post-COVID-19 complications

Post-COVID-19 complications involve a variety of long-lasting health complications emerging in various body systems. Since the prevalence of post-COVID-19 complications ranges from 8-47% in COVID-19 survivors, it represents a formidable challenge to COVID-19 survivors and the health care system. Post-COVID-19 complications have already been studied in the connection to risk factors linked to their higher probability of occurrence and higher severity, potential mechanisms underlying the pathogenesis of post-COVID-19 complications, and their functional and structural correlates. Vaccination status has been recently revealed to represent efficient prevention from long-term and severe post-COVID-19 complications. However, the exact mechanisms responsible for vaccine-induced protection against severe and long-lasting post-COVID-19 complications remain elusive. Also, to the best of our knowledge, the effects of new SARS-CoV-2 variants and SARS-CoV-2 reinfections on post-COVID-19 complications and their underlying pathogenesis remain to be investigated. This hypothesis article will be dedicated to the potential effects of vaccination status, SARS-CoV-2 reinfections, and new SARS-CoV-2 variants on post-COVID-19 complications and their underlying mechanisms Also, potential prevention strategies against post-COVID complications will be discussed.

Involvement of inflammatory responses in the brain to the onset of major depressive disorder due to stress exposure

Major depressive disorder (MDD) is a multifactorial disease affected by several environmental factors. Although several potential onset hypotheses have been identified, the molecular mechanisms underlying the pathogenesis of this disorder remain unclear. Several recent studies have suggested that among many environmental factors, inflammation and immune abnormalities in the brain or the peripheral tissues are associated with the onset of MDDs. Furthermore, several stress-related hypotheses have been proposed to explain the onset of MDDs. Thus, inflammation or immune abnormalities can be considered stress responses that occur within the brain or other tissues and are regarded as one of the mechanisms underlying the stress hypothesis of MDDs. Therefore, we introduce several current advances in inflammation studies in the brain that might be related to the pathophysiology of MDD due to stress exposure in this review.

Brain-Derived Neurotrophic Factor and Extracellular Vesicle-Derived miRNAs in an Italian Cohort of Individuals With Obesity: A Key to Explain the Link Between Depression and Atherothrombosis

Background

Obesity and depression are intertwined diseases often associated with an increased risk of cardiovascular (CV) complications. Brain-Derived Neurotrophic Factor (BDNF), altered in the brain both of subjects with depression and obesity, provides a potential link between depression and thrombosis. Since the relationship among peripheral BDNF, depression and obesity is not well-defined, the aim of the present report has been to address this issue taking advantage of the contribution played by extracellular vesicle (EV)-derived miRNAs.

Research Process

Associations among circulating BDNF, depression and EV-derived miRNAs related to atherothrombosis have been evaluated in a large Italian cohort of obese individuals (n = 743), characterized by the Beck Depression Inventory (BDI-II) score.

Results

BDI-II was negatively associated with BDNF levels without a significant impact of the rs6265 BDNF polymorphism; this association was modified by raised levels of IFN-γ. BDNF levels were linked to an increase of 80 EV-derived miRNAs and a decrease of 59 miRNAs related to atherosclerosis and thrombosis. Network analysis identified at least 18 genes targeted by these miRNAs, 7 of which involved in depression and CV risk. The observation of a possible link among BDNF, depression, and miRNAs related to atherothrombosis and depression in obesity is novel and may lead to a wider use of BDNF as a CV risk biomarker in this specific subject group.

Is post-COVID syndrome an autoimmune disease?

INTRODUCTION

: Coronavirus disease 2019 (COVID-19) causes a long-term and persistent condition with clinical features similar to previous virulent outbreaks and other epidemics. Currently, post-COVID syndrome (PCS) is recognized as a new entity in the context of SARS-CoV-2 infection. Though its pathogenesis is not completely understood, persistent inflammation from acute illness and the development of autoimmunity play a critical role in its development. As the pandemic develops, the increasing latent and overt autoimmunity cases indicate that PCS is at the intersection of autoimmunity.

AREAS COVERED

The mechanisms involved in the emergence of PCS, their similarities with post-viral and post-care syndromes, its inclusion in the spectrum of autoimmunity and possible targets for its treatment.

EXPERT OPINION

An autoimmune phenomenon plays a major role in most causative theories explaining PCS. Due to the wide scope of symptoms and pathophysiology associated with PCS, there is a need for both PCS definition and classification criteria (including severity scores). Longitudinal and controlled studies are necessary to better understand this new entity, and to confirm that PCS is the chronic phase of COVID-19 as well as to find what additional factors participate into its development. With the high prevalence of COVID-19 cases worldwide, together with the current evidence on latent autoimmunity in PCS, we may observe an increase of autoimmune diseases (ADs) in the coming years. Vaccination's effect on the development of PCS and ADs will also receive attention in the future. Health and social care services need to develop a new framework to deal with PCS.

COVID-19 2022 update: transition of the pandemic to the endemic phase

COVID-19, which is caused by the SARS-CoV-2, has ravaged the world for the past 2 years. Here, we review the current state of research into the disease with focus on its history, human genetics and genomics and the transition from the pandemic to the endemic phase. We are particularly concerned by the lack of solid information from the initial phases of the pandemic that highlighted the necessity for better preparation to face similar future threats. On the other hand, we are gratified by the progress into human genetic susceptibility investigations and we believe now is the time to explore the transition from the pandemic to the endemic phase. The latter will require worldwide vigilance and cooperation, especially in emerging countries. In the transition to the endemic phase, vaccination rates have lagged and developed countries should assist, as warranted, in bolstering vaccination rates worldwide. We also discuss the current status of vaccines and the outlook for COVID-19.

Possible Mechanisms Underlying Neurological Post-COVID Symptoms and Neurofeedback as a Potential Therapy

Theoretical considerations related to neurological post-COVID complications have become a serious issue in the COVID pandemic. We propose 3 theoretical hypotheses related to neurological post-COVID complications. First, pathophysiological processes responsible for long-term neurological complications caused by COVID-19 might have 2 phases: (1) Phase of acute Sars-CoV-2 infection linked with the pathogenesis responsible for the onset of COVID-19-related neurological complications and (2) the phase of post-acute Sars-CoV-2 infection linked with the pathogenesis responsible for long-lasting persistence of post-COVID neurological problems and/or exacerbation of another neurological pathologies. Second, post-COVID symptoms can be described and investigated from the perspective of dynamical system theory exploiting its fundamental concepts such as system parameters, attractors and criticality. Thirdly, neurofeedback may represent a promising therapy for neurological post-COVID complications. Based on the current knowledge related to neurofeedback and what is already known about neurological complications linked to acute COVID-19 and post-acute COVID-19 conditions, we propose that neurofeedback modalities, such as functional magnetic resonance-based neurofeedback, quantitative EEG-based neurofeedback, Othmer's method of rewarding individual optimal EEG frequency and heart rate variability-based biofeedback, represent a potential therapy for improvement of post-COVID symptoms.

Update of the Potential Treatments for Psychiatric and Neuropsychiatric Symptoms in the Context of the Post-COVID-19 Condition: Still a Lot of Suffering and Many More Things to Learn

Background: The World Health Organization (WHO) has defined a post-COVID-19 condition. Some of these symptoms can be categorized as psychiatric long COVID-19 if they appeared in the aftermath of COVID-19, including depression, anxiety, post-traumatic stress disorder, somatic symptoms disorders such as hyperventilation syndrome, fatigue, cognitive and sleep disorders. Psychiatric and neuropsychiatric post-COVID-19 present mental health specialists with difficult challenges because of its complexity and the multiple ways in which it integrates into a singular somatic context. Methods: We conducted a systematic research paradigm from SARS-CoV-2 using LitCOVID and Web of Science to search management strategies and potential treatments for psychiatric post-COVID-19 symptoms. Results: Management strategies must be based on a multidisciplinary approach to promote the global evaluation of psychiatric and physical symptoms, systematic detection and prevention. Selective serotonin reuptake inhibitors appear to be the best choice to treat post-COVID-19 depression and anxiety disorders, and tofisopam could be helpful for anxiety. Cognitive behavioral therapy techniques adjusted to post-COVID-19 fatigue, functional remediation, extracorporeal apheresis, transcutaneous auricular vagus nerve stimulation, monoclonal antibodies, flavonoids, oxytocin or L-carnitine all represent hypothetical therapeutic avenues that remain to be evaluated in clinical trials. Conclusions: Psychiatric and neuropsychiatric post-COVID-19 symptoms occur frequently and are debilitating. Attention should be paid to this condition and studies undertaken to specify the effective treatments.

The Potential Predictive Role of Tumour Necrosis Factor-α, Interleukin-1β, and Monocyte Chemoattractant Protein-1 for COVID-19 Patients Survival

Background

Tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and monocyte chemoattractant protein-1 (MCP-1) are early phase cytokines often encountered when the body is exposed to severe acute respiratory syndrome-associated-coronavirus-2. TNF-α, IL-1β, and MCP-1 are pro-inflammatory cytokines critical in the defence response against systemic infection and injury. Therefore, TNF-α, IL-1β, and MCP-1 are the most aggressive responses to viral infections in the acute phase, so they can be used to determine the survival of coronavirus disease 2019 (COVID-19) patients.

Purpose

The study aimed to determine the levels of TNF-α, IL-1β, and MCP-1 as predictors of survival for COVID-19 patients.

Patients and Methods

A prospective cohort study was conducted on confirmed COVID-19 by a reverse-transcriptase-polymerase-chain-reaction (RT-PCR) in 84 adults admitted to the hospital in Indonesia. TNF-α, IL-1β, and MCP-1 level were measured from serum subjects using the enzyme-linked immunosorbent assay.

Results

The results from logistic regression modelling of the survival status of COVID-19 patients based on TNF-α, IL-1β, and MCP-1 levels were significant (p-value=0.024). The predictors of all cytokines had P Wald <0.05, so the three cytokines could be used simultaneously to predict the survival status of COVID-19 patients. MCP-1 has the most dominant risk relative value (2.76; 95% CI; 2.53–4.68) compared to TNF-α and IL-1β in predicting patient survival.

Conclusion

TNF-α, IL-1β, and MCP-1 as markers of acute systemic inflammatory cytokines can be measured at the beginning of hospitalisation of COVID-19 patients for early diagnosis of disease severity so that healthcare professionals can determine clinical guidance needs for therapeutic programs.

Persistent Autoimmune Activation and Proinflammatory State in Post-COVID Syndrome

Background

The immunopathological pathways enabling post-COVID syndrome (PCS) development are not entirely known. We underwent a longitudinal analysis of patients with COVID-19 who developed PCS aiming to evaluate the autoimmune and immunological status associated with this condition.

Methods

Thirty-three patients were included for longitudinal clinical and autoantibody analyses of whom 12 patients were assessed for cytokines and lymphocyte populations. Patients were followed during 7-11 months after acute COVID-19. Autoimmune profile and immunological status were evaluated mainly by enzyme-linked-immunosorbent assays and flow cytometry.

Results

Latent autoimmunity and overt autoimmunity persisted over time. A proinflammatory state was observed in patients with PCS characterized by upregulated IFN-α, TNF-α, G-CSF, IL-17A, IL-6, IL-1β, and IL-13, whereas IP-10 was decreased. In addition, PCS was characterized by increased levels of Th9, CD8+ effector T cells, naive B cells, and CD4+ effector memory T cells. Total levels of IgG S1-SARS-CoV-2 antibodies remained elevated over time.

Discussion

The clinical manifestations of PCS are associated with the persistence of a proinflammatory, and effector phenotype induced by SARS-CoV-2 infection. This long-term persistent immune activation may contribute to the development of latent and overt autoimmunity. Results suggest the need to evaluate the role of immunomodulation in the treatment of PCS.

Post-COVID-19 Syndrome: Involvement and Interactions between Respiratory, Cardiovascular and Nervous Systems

Though the acute effects of SARS-CoV-2 infection have been extensively reported, the long-term effects are less well described. Specifically, while clinicians endure to battle COVID-19, we also need to develop broad strategies to manage post-COVID-19 symptoms and encourage those affected to seek suitable care. This review addresses the possible involvement of the lung, heart and brain in post-viral syndromes and describes suggested management of post-COVID-19 syndrome. Post-COVID-19 respiratory manifestations comprise coughing and shortness of breath. Furthermore, arrhythmias, palpitations, hypotension, increased heart rate, venous thromboembolic diseases, myocarditis and acute heart failure are usual cardiovascular events. Among neurological manifestations, headache, peripheral neuropathy symptoms, memory issues, lack of concentration and sleep disorders are most commonly observed with varying frequencies. Finally, mental health issues affecting mental abilities and mood fluctuations, namely anxiety and depression, are frequently seen. Finally, long COVID is a complex syndrome with protracted heterogeneous symptoms, and patients who experience post-COVID-19 sequelae require personalized treatment as well as ongoing support.

Syncytin, envelope protein of human endogenous retrovirus (HERV): no longer 'fossil' in human genome

Human endogenous retroviruses (HERVs) are 'fossil viruses' that resulted from stable integrations of exogenous retroviruses throughout evolution. HERVs are defective and do not produce infectious viral particles. However, some HERVs retain a limited coding capacity and produce retroviral transcripts and proteins, which function in human developmental process and various pathologies, including many cancers and neurological diseases. Recently, it has been reported that HERVs are differently expressed in COVID-19 disease caused by infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we discuss the molecular structure and function of HERV ENV proteins, particularly syncytins, and their conventional roles in human development and diseases, and potential involvement in COVID-19 regarding the newly reported mental symptoms. We also address COVID-19 vaccine-related infertility concerns arising from the similarity of syncytin with the spike protein of SARS-CoV-2, which have been proved invalid.

Clinical Aspects of Manic Episodes After SARS-CoV-2 Contagion or COVID-19

As COVID-19 pandemic spread all over the world, it brought serious health consequences in every medical field, including mental health. Not only healthcare professionals were more prone to develop anxiety, depression, and stress, but the general population suffered as well. Some of those who had no prior history of a psychiatric disease developed peculiar symptoms following infection with SARS-CoV-2, mostly because of psychological and social issues triggered by the pandemic. People developed traumatic memories, and hypochondria, probably triggered by social isolation and stress. Infection with SARS-CoV-2 has influenced the mental health of psychiatric patients as well, exacerbating prior psychiatric conditions. In this review, we focus on analyzing those cases of mania in the context of bipolar disorder (BD) reported after COVID-19 disease, both in people with no prior psychiatric history and in psychiatric patients who suffered an exacerbation of the disease. Results have shown that COVID-19 may trigger a pre-existing BD or unmask an unknown BD, due to social and psychological influences (decreased social interaction, change in sleep patterns) and through biological pathways both (neuroinflammation and neuroinvasion through ACE-2 receptors expressed in the peripheral and central nervous systems (PNS and CNS respectively). No direct correlation was found between the severity of COVID-19 disease and manic symptoms. All cases presenting severe symptoms of both diseases needed specific medical treatment, meaning that they concur but are separate in the treatment strategy needed. This review highlights the importance of a now widespread viral disease as a potential agent unmasking and exacerbating bipolar mood disorder, and it can hopefully help physicians in establishing a rapid diagnosis and treatment, and pave the road for future research on neuroinflammation triggered by SARS-CoV-2.

Post-COVID-19 Depressive Symptoms: Epidemiology, Pathophysiology, and Pharmacological Treatment

The Coronavirus Disease 2019 (COVID-19) pandemic is still spreading worldwide over 2 years since its outbreak. The psychopathological implications in COVID-19 survivors such as depression, anxiety, and cognitive impairments are now recognized as primary symptoms of the "post-acute COVID-19 syndrome." Depressive psychopathology was reported in around 35% of patients at short, medium, and long-term follow-up after the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. Post-COVID-19 depressive symptoms are known to increase fatigue and affect neurocognitive functioning, sleep, quality of life, and global functioning in COVID-19 survivors. The psychopathological mechanisms underlying post-COVID-19 depressive symptoms are mainly related to the inflammation triggered by the peripheral immune-inflammatory response to the viral infection and to the persistent psychological burden during and after infection. The large number of SARS-CoV-2-infected patients and the high prevalence of post-COVID-19 depressive symptoms may significantly increase the pool of people suffering from depressive disorders. Therefore, it is essential to screen, diagnose, treat, and monitor COVID-19 survivors' psychopathology to counteract the depression disease burden and related years of life lived with disability. This paper reviews the current literature in order to synthesize the available evidence regarding epidemiology, clinical features, neurobiological underpinning, and pharmacological treatment of post-COVID-19 depressive symptoms.

Increased Kynurenine Indicates a Fatal Course of COVID-19

(1) Background: An inefficient immune response accompanied by an overwhelming inflammatory reaction is involved in severe courses of COVID-19. Kynurenine (KYN) has important immune-modulatory functions and may contribute to a failure in controlling SARS-CoV-2. The present study aims to explore biomarkers that hint at a fatal outcome of COVID-19 early on. (2) Methods: We established a cohort of 148 hospitalized COVID-19 patients for this study. Thirty-one patients died due to a severe COVID-19 course, and 117 recovered within 90 days. We built a biobank by collecting left-over material from these patients whenever blood arrived at the central laboratory of our University hospital for analysis of routine markers. The scientific laboratory analysis comprised KYN, Tryptophan (TRP), KYN/TRP ratio, ferritin, interleukin-6 (IL-6), C-reactive protein (CRP), creatinine, N-terminal pro-natriuretic peptide (NTproBNP), troponin T (TnT), fibrinogen, D-Dimer, prothrombin time (PT), activated partial thromboplastin time (aPTT), antithrombin (AT), protein C, protein S, factor XIII, lupus aPTT, angiotensin-2, vitamin D metabolites, and telomeres in all COVID-19 patients. Basic clinical characteristics and anteceding diseases including cardiovascular, oncologic, renal, hypertension, pulmonary, metabolic (diabetes, obesity) were recorded in a database together with the laboratory data. (3) Results: At the time of diagnosis of SARS-CoV-2 infection those patients who deceased within 90 days afterwards due to COVID-19, had a significantly higher age, higher KYN, KYN/TRP ratio, ferritin, creatinine, and NTproBNP values than SARS-CoV-2 patients who survived COVID-19 along the same time span. In a Kaplan-Meier analysis the variables age, KYN, ferritin, D-Dimer, TnT, NTproBNP, and creatinine showed a significant influence on survival time. Gender, however, showed no influence. In a combined Cox regression analysis KYN had the highest hazard ratio (1.188, 95% CI: 1.071-1.319) followed by age (1.041, 95% CI: 1.011-1.073). In a ROC analysis, KYN values above the cut off limit of 4.82 nmol/l (as specified by Youden index) had a sensitivity of 82% (95% CI: 66-95%) and a specificity of 72% (95% CI: 65-82%) to predict COVID-19 related death within 90 days observation time. (4) Conclusions: Kynurenine is a promising blood biomarker to predict an increased risk of mortality in SARS-CoV-2 infected people already at the time of the first positive SARS-CoV-2 verification detected in these persons.