Increased levels of plasma IL-1b and BDNF can predict resistant depression patients

Atractylodin ameliorates lipopolysaccharide-induced depressive-like behaviors in mice through reducing neuroinflammation and neuronal damage

Depression is a psychiatric disorder associated with multiple factors including microglia-mediated neuroinflammation. Although atractylodin exerted a variety of biological activities, however the effect of atractylodin on neuroinflammation-related depression was still unclear. In this study, the lipopolysaccharide (LPS)-induced mouse model was used to explore the antidepressant effects and molecular mechanisms of atractylodin. The results showed that atractylodin increased sugar preference, also reduced immobility time in FST and TST. Further study showed atractylodin reduced the oxidative stress and the activation of microglia in mouse hippocampus, also inhibited the level of cytokine release, especially IL-1β. The results of western blotting showed that atractylodin significantly inhibited the expression of NLRP3 and pro-IL1β via inhibition of NF-κB pathway. Our studies showed that atractylodin upregulated BDNF/Akt pathway in mouse hippocampus. Therefore, this study firstly indicated that atractylodin can ameliorate lipopolysaccharide-induced depressive-like behaviors in mice through reducing neuroinflammation and neuronal damage, and its molecular mechanism may be associated with the decrease of the expression of NLRP3 inflammasome and upregulation of BDNF/Akt pathway.

Plasma and Platelet Brain-Derived Neurotrophic Factor (BDNF) Levels in Bipolar Disorder Patients with Post-Traumatic Stress Disorder (PTSD) or in a Major Depressive Episode Compared to Healthy Controls

Post-traumatic stress disorder (PTSD) is a highly disabling mental disorder arising after traumatism exposure, often revealing critical and complex courses when comorbidity with bipolar disorder (BD) occurs. To search for PTSD or depression biomarkers that would help clinicians define BD presentations, this study aimed at preliminarily evaluating circulating brain-derived-neurotrophic factor (BDNF) levels in BD subjects with PTSD or experiencing a major depressive episode versus controls. Two bloodstream BDNF components were specifically investigated, the storage (intraplatelet) and the released (plasma) ones, both as adaptogenic/repair signals during neuroendocrine stress response dynamics. Bipolar patients with PTSD (n = 20) or in a major depressive episode (n = 20) were rigorously recruited together with unrelated healthy controls (n = 24) and subsequently examined by psychiatric questionnaires and blood samplings. Platelet-poor plasma (PPP) and intraplatelet (PLT) BDNF were measured by ELISA assays. The results showed markedly higher intraplatelet vs. plasma BDNF, confirming platelets' role in neurotrophin transport/storage. No between-group PPP-BDNF difference was reported, whereas PLT-BDNF was significantly reduced in depressed BD patients. PLT-BDNF negatively correlated with mood scores but not with PTSD items like PPP-BDNF, which instead displayed opposite correlation trends with depression and manic severity. Present findings highlight PLT-BDNF as more reliable at detecting depression than PTSD in BD, encouraging further study into BDNF variability contextually with immune-inflammatory parameters in wider cohorts of differentially symptomatic bipolar patients.

Biological correlates of treatment resistant depression: a review of peripheral biomarkers

Introduction

Many patients fail to respond to multiple antidepressant interventions, being defined as "treatment-resistant depression" (TRD) patients. TRD is usually associated with increased severity and chronicity of symptoms, increased risk of comorbidity, and higher suicide rates, which make the clinical management challenging. Efforts to distinguish between TRD patients and those who will respond to treatment have been unfruitful so far. Several studies have tried to identify the biological, psychopathological, and psychosocial correlates of depression, with particular attention to the inflammatory system. In this paper we aim to review available studies assessing the full range of biomarkers in TRD patients in order to reshape TRD definition and improve its diagnosis, treatment, and prognosis.

Methods

We searched the most relevant medical databases and included studies reporting original data on possible biomarkers of TRD. The keywords "treatment resistant depression" or "TRD" matched with "biomarker," "inflammation," "hormone," "cytokine" or "biological marker" were entered in PubMed, ISI Web of Knowledge and SCOPUS databases. Articles were included if they included a comparison with healthy controls (HC).

Results

Of the 1878 papers identified, 35 were included in the present study. Higher plasma levels of IL-6 and TNF-α were detected in TRD patients compared to HC. While only a few studies on cortisol have been found, four papers showed elevated levels of C-reactive protein among these patients and four articles focused on immunological cells. Altered kynurenine metabolism in TRD patients was reported in two studies, while contrasting results were found with regard to BDNF.

Conclusion

Only a few biological alterations correlate with TRD. TNF-α seems to be the most relevant biomarker to discriminate TRD patients from both HC and treatment-responsive MDD patients. Moreover, several discrepancies among studies have been found, due to methodological differences and the lack of a standardized diagnostic definition of TRD.

Brain-Derived Neurotrophic Factor (BDNF) as a Predictor of Treatment Response in Major Depressive Disorder (MDD): A Systematic Review

Brain-derived neurotrophic factor (BDNF) has been studied as a biomarker of major depressive disorder (MDD). Besides diagnostic biomarkers, clinically useful biomarkers can inform response to treatment. We aimed to review all studies that sought to relate BDNF baseline levels, or BDNF polymorphisms, with response to treatment in MDD. In order to achieve this, we performed a systematic review of studies that explored the relation of BDNF with both pharmacological and non-pharmacological treatment. Finally, we reviewed the evidence that relates peripheral levels of BDNF and BDNF polymorphisms with the development and management of treatment-resistant depression.

Variation of Circulating Brain-Derived Neurotrophic Factor (BDNF) in Depression: Relationships with Inflammatory Indices, Metabolic Status and Patients' Clinical Features

This study seeks to offer a contribution to the method of subtyping major depressed patients by exploring the possible relationships between circulating brain-derived neurotrophic factor (BDNF), different peripheral inflammatory/metabolic markers in the blood and clinical characteristics. Thirty-nine patients, thoroughly diagnosed according to the DSM-5 criteria, underwent a comprehensive set of evaluations encompassing structured interviews, rating scales and a panel of blood tests. Correlation and comparison analyses were carried out by means of non-parametric statistical tests. Concurrently, a principal component analysis was performed to explain biochemical variance. The findings of our research unveiled that leukocyte counts, their ratios and other inflammatory parameters are positively correlated with depression scores. Moreover, we found variations within the BDNF pools of depressed patients. Specifically, higher levels of platelet-poor plasma BDNF (PPP-BDNF) were correlated with augmented inflammatory markers in patients showing specific episode characteristics, whereas reduced platelet BDNF (PLT-BDNF) provided a better indication of the changes that were linked to a diagnosis of long-term depression. Our findings suggest that PPP-BDNF and PLT-BDNF might differentiate depression conditions. They also imply usefulness in appraising peripheral biomarker profiles in patients for a deeper characterization of major depressive episodes. At the same time, it is plausible that they might constitute novel avenues for developing more tailored therapeutic strategies for patients with MDs.

Cytokine level in patients with mood disorder, alcohol use disorder and their comorbidity

OBJECTIVES

Because alcohol use disorder (AUD) is often accompanied by mood disorder (MD) and both alcoholism and depression result in activation of the immune system, this study compares serum cytokine levels in the presence of co-morbidity with those in either AUD or MD alone.

METHODS

In this naturalistic prospective study the levels of 15 different cytokines were measured in serum samples of patients with MD (n = 43), participants with combined AUD-MD (n = 44) and AUD without MD (n = 42). The levels were compared cross-sectionally among themselves and with those in 50 healthy volunteers.

RESULTS

Pro-inflammatory IFN-2α levels were consistently significantly higher and anti-inflammatory IL-1RA significantly lower in all study groups in comparison to healthy volunteers. In the MD only group we found increased IL-6 (p = 0.001), IL-7 (p = 0.001) and IL-13 (p = 0.006) levels, and decreased TNFα (p = 0.0001), IL-1RA (p = 0.012), IL-10 (p = 0.002) compared with group MD + AUD. Patients with AUD only showed elevated levels of IL-1β (p = 0.046), IL-2 (p = 0.004), IL-7 (p = 0.0001), IL-4 (p = 0.049) and IL-13 (p = 0.015) in contrast with MD + AUD group.

CONCLUSIONS

Because the interactions of alcohol with peripheral and cerebral immune systems are multifaceted, the pertinent connection to the mechanism how alcohol consumption contributes to the development of mood disorders cannot be properly explored.

Inflammation and Mental Health Disorders: Immunomodulation as a Potential Therapy for Psychiatric Conditions

Mood disorders are the leading cause of disability worldwide and their incidence has significantly increased after the COVID-19 pandemic. Despite the continuous surge in the number of people diagnosed with psychiatric disorders, the treatment methods for these conditions remain limited. A significant number of people either do not respond to therapy or discontinue the drugs due to their severe side effects. Therefore, alternative therapeutic interventions are needed. Previous studies have shown a correlation between immunological alterations and the occurrence of mental health disorders, yet immunomodulatory therapies have been barely investigated for combating psychiatric conditions. In this article, we have reviewed the immunological alterations that occur during the onset of mental health disorders, including microglial activation, an increased number of circulating innate immune cells, reduced activity of natural killer cells, altered T cell morphology and functionality, and an increased secretion of pro-inflammatory cytokines. This article also examines key studies that demonstrate the therapeutic efficacy of anti-inflammatory medications in mental health disorders. These studies suggest that immunomodulation can potentially be used as a complementary therapy for controlling psychiatric conditions after careful screening of candidate drugs and consideration of their efficacy and side effects in clinical trials.

The NLRP3 inflammasome in depression: Potential mechanisms and therapies

Increasing evidence suggests that the failure of clinical antidepressants may be related with neuroinflammation. The NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is an intracellular multiprotein complex, and has been considered as a key contributor to the development of neuroinflammation. Inhibition of NLRP3 inflammasome is an effective method for depression treatment. In this review, we summarized current researches highlighting the role of NLRP3 inflammasome in the pathology of depression. Firstly, we discussed NLRP3 inflammasome activation in patients with depression and animal models. Secondly, we outlined the possible mechanisms driving the activation of NLRP3 inflammasome. Thirdly, we discussed the pathogenetic role of NLRP3 inflammasome in depression. Finally, we overviewed the current and potential antidepressants targeting the NLRP3 inflammasome. Overall, the inhibition of NLRP3 inflammasome activation may be a potential therapeutic strategy for inflammation-related depression.

Neuronal-microglial liver X receptor β activating decrease neuroinflammation and chronic stress-induced depression-related behavior in mice

Depression is accompanied by excessive neuroinflammation. Liver X receptor β (LXRβ) has been reported as a newly emerging target that exerts systemic and organic inflammation modulation. However, the modulatory mechanism in alleviating neuroinflammation are far from being revealed. In the current study, depression-related behaviors in mice were induced by chronic unpredictable mild stress (CUMS) and corticosterone (CORT) drinking. Mice received either TO901317, PLX-5622 and intra- bilateral basolateral amygdale (BLA) injection of rAAV9-hSyn-hM3D(Gq)-eGFP to activate LXRβ, eliminate microglia and pharmacogenetic activate neurons in BLA, respectively, followed by behavioral tests. Microglial pro-inflammatory and pro-phagocytic activation, as well as nuclear factor-κB (NF-κB) signaling pathway, NLRP3 inflammasome activation and interleukin-1β (IL-1β) release in BLA were investigated. Moreover, pro-inflammatory activation of BV2 cells-induced by CORT with or without TO901317 was detected. Neuroinflammation indicated by IL-1β release was measured in a co-culture system of HT22-primary microglia with or without TO901317. Our results indicated that chronic stress induced depression-related behaviors, which were accompanied with microglial pro-inflammatory and pro-phagocytic activation, as well as NF-κB signaling pathway and NLRP3 inflammasome activation in BLA. Accordingly, pharmacological activation of LXRβ inhibited microglial pro-inflammatory and pro-phagocytic activation, as well as NF-κB signaling pathway and NLRP3 inflammasome activation, and IL-1β release both in vivo and in vitro. Finally, both elimination of microglia and pharmacogenetic activation of neurons in BLA protected mice from chronic stress-induced depression-related behavior. Collectively, pharmacological activation of neuronal-microglial LXRβ alleviates depression-related behavior by modulating excessive neuroinflammation via inhibiting NF-κB signaling pathway and NLRP3 inflammasome activation.

Earlier age of onset is associated with a pro-inflammatory state in major depressive disorder

Major depressive disorder (MDD) is a common condition that affects the general population over a wide range of ages, regardless of gender and social background. Early-onset of MDD in adulthood, between ages of 18 and 30 years, is associated with worse outcomes and increased years of disability. Stress load and physical health have been associated with age of onset in MDD. We aim to investigate whether early onset MDD might be associated with changes in systemic inflammatory markers. We examined levels of following cytokines: IL-1β, IL-6, IL-10 and TNFα in 234 patients with MDD. Higher serum levels of TNFα and IL-1β are associated with the early onset of the disorder in patients with MDD. IL-6 levels were also higher in the early onset group and IL-10 levels were higher in the late onset group, but with no significant difference. Changes in the anti-inflammatory/pro-inflammatory balance have been described in mood disorders and may be implicated in its severity and pattern of progression. Our findings reinforce that higher serum levels of IL-1β and TNFα may be associated with the earlier onset subgroup of MDD patients. Future research that target inflammatory markers of immune modulation may be, key in the search for novel preventative therapeutics.

Comparison of cognitive impairments with lipid profiles and inflammatory biomarkers in unipolar and bipolar depression

Cognitive impairments is one of important accompanied symptom in Unipolar depressive disorder (UD) and bipolar disorder (BD) that was hard to distinguish, as their diagnosis is based on behavioural observations and subjective symptoms. In this study, we could highlight the difference of cognitive ability in UD and BD by testing lipid profiles and inflammatory biomarkers in major depressive episodes (MDE). 207 subjects (96 unipolar and 111 bipolar depressed patients) were included in this study. We applied Montreal Cognitive Assessment (MoCA) to test cognitive ability. The 24-item Hamilton Depression Rating Scale was used for assessment at the beginning of treatment. A series of clinical variables and lipid profiles were collected from clinic record. We detected pro-inflammatory biomarkers Interleukin-1β (IL-1β), Interleukin-6 (IL-6), C-reaction protein (CRP) levels and brain-derived neurotrophic factor (BDNF) by enzyme linked immunosorbent assay. From the results, cognitive impairments were more popular in BD than UD, most obviously in severe cognitive impairments (MoCA score<23). And UD showed better cognitive ability than BD in MoCA, particularly in language domain. Compared lipid profiles like total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (ApoA1), Apolipoprotein B (ApoB) and lipoprotein α (Lpα), we found that ApoB was higher in BD than UD that maybe a risk factor in cognition. There was no obviously difference in TC, TG, HDL-C, LDL-C, ApoA1, or Lpα. Also, we found CRP level in BD was higher than UD, and showed no significant difference in IL-1β and IL-6 levels. Furthermore, BDNF level which was neurotrophic biomarker for cognition and mood was significantly declined in BD compared with UD. Correlation analysis showed that ApoB and CRP was negative closed associated with MoCA scores. And BDNF level was positive related with cognitive ability in MDE patients. From our results mentioned that quantitative lipid profiles and inflammatory biomarkers analysis might help to objectively identify between these disorders and up our understanding of their pathophysiology. And ApoB, CRP and BDNF could be as potential peripheral candidates in cognitive evaluation to distinguish UD and BD.

Effects of a Single Sub-Anesthetic Dose of Ketamine on Postoperative Emotional Responses and Inflammatory Factors in Colorectal Cancer Patients

Objective: To investigate the effect of a single sub-anesthetic dose of ketamine on postoperative anxiety, depression, and inflammatory factors in patients with colorectal cancer. Methods: A total of 104 patients undergoing selective colorectal surgery in our hospital from Jan 2015 to Oct 2017 were included and randomly assigned (1:1:1:1) into a 0.1 mg kg^-1 ketamine group (K1 group), 0.2 mg kg^-1 ketamine group (K2 group), 0.3 mg kg^-1 ketamine group (K3 group), or control group (C group). Corresponding doses of ketamine were given intravenously in the K groups (K1, K2, and K3 groups) 5 min before operation, and the same amount of normal saline was given in the C group. The intravenous analgesia program was identical in the four groups. The patients' emotional reactions (anxiety and depression) were assessed by the Hospital Anxiety and Depression Scale (HAD), the quality of postoperative recovery was evaluated by the Quality of Recovery-40 (QoR-40) questionnaire, and the levels of IL-6, IL-8, and TNF-α in peripheral blood were detected by enzyme-linked immunosorbent assay (ELISA) on the day before operation and within 24, 48, and 72 h post-operation respectively. Pain was estimated by the visual analog scale (VAS), and sedation was assessed with Ramsay score 30 min after extubation. The time points of anesthetic end and extubation were recorded. The complications during anesthesia and recovery such as cough and agitation 30 min after extubation were recorded. Results: The anxiety score (HAD-A) and depression score (HAD-D) of the K3 group were significantly lower than those of the C group post-operation (p < 0.05). The QoR-40 score of the K3 group was significantly higher than that of the C group (p < 0.05). The serum levels of IL-6, IL-8, and TNF-α in the K3 group were significantly lower than those in the C group (p < 0.05 and p < 0.01). There were no significant differences in HAD-A, HAD-D, and QoR-40 scores or serum levels of IL-6, IL-8, and TNF-α between the K1 and K2 groups and the C group. There were no significant differences in VAS pain score or Ramsay sedation score among the four groups 30 min after extubation. There were no significant differences in extubation time, postoperative cough, emergence agitation, or delirium among the four groups. Dizziness, nausea, vomiting, diplopia, or other adverse reactions were not found 30 min after extubation. Conclusion: A single sub-anesthetic dose (0.3 mg kg^-1) of ketamine can significantly improve the postoperative anxiety and depression of colorectal cancer patients and reduce the levels of IL-6, IL-8, and TNF-α.

Transcriptional biomarkers of response to pharmacological treatments in severe mental disorders: A systematic review

Variation in the expression level and activity of genes involved in drug disposition and action in tissues of pharmacological importance have been increasingly investigated in patients treated with psychotropic drugs. Findings are promising, but reliable predictive biomarkers of response have yet to be identified. Here we conducted a PRISMA-compliant systematic search of PubMed, Scopus and PsycInfo up to 12 September 2020 for studies investigating RNA expression levels in cells or biofluids from patients with major depressive disorder, schizophrenia or bipolar disorder characterized for response to psychotropic drugs (antidepressants, antipsychotics or mood stabilizers) or adverse effects. Among 5497 retrieved studies, 123 (63 on antidepressants, 33 on antipsychotics and 27 on mood stabilizers) met inclusion criteria. Studies were either focused on mRNAs (n = 96), microRNAs (n = 19) or long non-coding RNAs (n = 1), with only a minority investigating both mRNAs and microRNAs levels (n = 7). The most replicated results include genes playing a role in inflammation (antidepressants), neurotransmission (antidepressants and antipsychotics) or mitochondrial function (mood stabilizers). Compared to those investigating response to antidepressants, studies focused on antipsychotics or mood stabilizers more often showed lower sample size and lacked replication. Strengths and limitations of available studies are presented and discussed in light of the specific designs, methodology and clinical characterization of included patients for transcriptomic compared to DNA-based studies. Finally, future directions of transcriptomics of psychopharmacological interventions in psychiatric disorders are discussed.

Brain-derived neurotrophic factor and inflammation in depression: Pathogenic partners in crime?

Major depressive disorder is a debilitating disorder affecting millions of people each year. Brain-derived neurotrophic factor (BDNF) and inflammation are two prominent biologic risk factors in the pathogenesis of depression that have received considerable attention. Many clinical and animal studies have highlighted associations between low levels of BDNF or high levels of inflammatory markers and the development of behavioral symptoms of depression. However, less is known about potential interaction between BDNF and inflammation, particularly within the central nervous system. Emerging evidence suggests that there is bidirectional regulation between these factors with important implications for the development of depressive symptoms and anti-depressant response. Elevated levels of inflammatory mediators have been shown to reduce expression of BDNF, and BDNF may play an important negative regulatory role on inflammation within the brain. Understanding this interaction more fully within the context of neuropsychiatric disease is important for both developing a fuller understanding of biological pathogenesis of depression and for identifying novel therapeutic opportunities. Here we review these two prominent risk factors for depression with a particular focus on pathogenic implications of their interaction.

Inflammatory Markers in Substance Use and Mood Disorders: A Neuroimaging Perspective

Chronic exposure to addictive drugs in substance use disorders and stressors in mood disorders render the brain more vulnerable to inflammation. Inflammation in the brain, or neuroinflammation, is characterized by gliosis, microglial activation, and sustained release of cytokines, chemokines, and pro-inflammatory factors compromising the permeability of the blood-brain barrier. There is increased curiosity in understanding how substance misuse and/or repeated stress exposure affect inflammation and contribute to abnormal neuronal activity, altered neuroplasticity, and impaired cognitive control, which eventually promote compulsive drug-use behaviors and worsen mood disorders. This review will emphasize human imaging studies to explore the link between brain function and peripheral markers of inflammation in substance use disorders and mood disorders.

Neurological and psychiatric presentations associated with COVID-19

The objective is to investigate coronavirus disease 2019 (COVID-19)-associated neurological and psychiatric effects and explore possible pathogenic mechanisms. This study included 77 patients with laboratory-confirmed COVID-19 in Wuhan, China. Neurological manifestations were evaluated by well-trained neurologists, psychologists, psychiatric presentations and biochemical changes were evaluated using the Generalized Anxiety Disorder 7-item scale, Patient Health Questionnaire-9, Brief Psychiatric Rating Scale, and electronic medical records. Eighteen (23.4%) patients presented with neurological symptoms. Patients with neurological presentations had higher urea nitrogen, cystatin C, and high-sensitivity C-reactive protein levels and lower basophil counts. Among them, patients with muscle involvement had higher urea nitrogen and cystatin C levels but lower basophil counts. In addition, patients with psychiatric presentations were older and had higher interleukin (IL)-6 and IL-10 levels and higher alkaline phosphatase, R-glutamate transferase, and urea nitrogen levels. Moreover, patients with anxiety had higher IL-6 and IL-10 levels than those without, and patients with moderate depression had higher CD8 + T cell counts and lower CD4 + /CD8 + ratios than other patients. This study indicates that the central nervous system may be influenced in patients with COVID-19, and the pathological mechanisms may be related to direct virus invasion of the central nervous system, infection-mediated overreaction of the immune system, and aberrant serum pro-inflammatory factors. In addition, basophils and cystatin C may also play important roles during these pathological processes. Our findings suggest that neurological and psychiatric presentations should be evaluated and managed in patients with COVID-19. Further studies are needed to investigate the underlying mechanisms.

Biomarkers of Post-COVID Depression

The COVID-19 pandemic is spreading around the world and 187 million people have already been affected. One of its after-effects is post-COVID depression, which, according to the latest data, affects up to 40% of people who have had SARS-CoV-2 infection. A very important issue for the mental health of the general population is to look for the causes of this complication and its biomarkers. This will help in faster diagnosis and effective treatment of the affected patients. In our work, we focused on the search for major depressive disorder (MDD) biomarkers, which are also present in COVID-19 patients and may influence the development of post-COVID depression. For this purpose, we searched PubMed, Scopus and Google Scholar scientific literature databases using keywords such as 'COVID-19', 'SARS-CoV-2', 'depression', 'post-COVID', 'biomarkers' and others. Among the biomarkers found, the most important that were frequently described are increased levels of interleukin 6 (IL-6), soluble interleukin 6 receptor (sIL-6R), interleukin 1 β (IL-1β), tumor necrosis factor α (TNF-α), interferon gamma (IFN-γ), interleukin 10 (IL-10), interleukin 2 (IL-2), soluble interleukin 2 receptor (sIL-2R), C-reactive protein (CRP), Monocyte Chemoattractant Protein-1 (MCP-1), serum amyloid a (SAA1) and metabolites of the kynurenine pathway, as well as decreased brain derived neurotrophic factor (BDNF) and tryptophan (TRP). The biomarkers identified by us indicate the etiopathogenesis of post-COVID depression analogous to the leading inflammatory hypothesis of MDD.

Efficacy and Safety of Cannabidiol Plus Standard Care vs Standard Care Alone for the Treatment of Emotional Exhaustion and Burnout Among Frontline Health Care Workers During the COVID-19 Pandemic: A Randomized Clinical Trial

IMPORTANCE

Frontline health care professionals who work with patients with COVID-19 have an increased incidence of burnout symptoms. Cannabidiol (CBD) has anxiolytic and antidepressant properties and may be capable of reducing emotional exhaustion and burnout symptoms.

OBJECTIVE

To investigate the safety and efficacy of CBD therapy for the reduction of emotional exhaustion and burnout symptoms among frontline health care professionals working with patients with COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

This prospective open-label single-site randomized clinical trial used a 1:1 block randomization design to examine emotional exhaustion and burnout symptoms among frontline health care professionals (physicians, nurses, and physical therapists) working with patients with COVID-19 at the Ribeirão Preto Medical School University Hospital in São Paulo, Brazil. Participants were enrolled between June 12 and November 12, 2020. A total of 214 health care professionals were recruited and assessed for eligibility, and 120 participants were randomized in a 1:1 ratio by a researcher who was not directly involved with data collection.

INTERVENTIONS

Cannabidiol, 300 mg (150 mg twice per day), plus standard care or standard care alone for 28 days.

MAIN OUTCOMES AND MEASURES

The primary outcome was emotional exhaustion and burnout symptoms, which were assessed for 28 days using the emotional exhaustion subscale of the Brazilian version of the Maslach Burnout Inventory-Human Services Survey for Medical Personnel.

RESULTS

A total of 120 participants were randomized to receive either CBD, 300 mg, plus standard care (treatment arm; n = 61) or standard care alone (control arm; n = 59) for 28 days. Of those, 118 participants (59 participants in each arm; 79 women [66.9%]; mean age, 33.6 years [95% CI, 32.3-34.9 years]) received the intervention and were included in the efficacy analysis. In the treatment arm, scores on the emotional exhaustion subscale of the Maslach Burnout Inventory significantly decreased at day 14 (mean difference, 4.14 points; 95% CI, 1.47-6.80 points; partial eta squared [ηp2] = 0.08), day 21 (mean difference, 4.34 points; 95% CI, 0.94-7.73 points; ηp2 = 0.05), and day 28 (mean difference, 4.01 points; 95% CI, 0.43-7.59 points; ηp2 = 0.04). However, 5 participants, all of whom were in the treatment group, experienced serious adverse events: 4 cases of elevated liver enzymes (1 critical and 3 mild, with the mild elevations reported at the final 28-day assessment) and 1 case of severe pharmacodermia. In 2 of those cases (1 with critical elevation of liver enzymes and 1 with severe pharmacodermia), CBD therapy was discontinued, and the participants had a full recovery.

CONCLUSIONS AND RELEVANCE

In this study, CBD therapy reduced symptoms of burnout and emotional exhaustion among health care professionals working with patients during the COVID-19 pandemic. However, it is necessary to balance the benefits of CBD therapy with potential undesired or adverse effects. Future double-blind placebo-controlled clinical trials are needed to confirm the present findings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04504877.

State-of-the-Art: Inflammatory and Metabolic Markers in Mood Disorders

Mounting evidence highlights the involvement of inflammatory/immune systems and their relationships with neurotransmitters and different metabolic processes in mood disorders. Nevertheless, there is a general agreement that available findings are still inconclusive. Therefore, further investigations are required, aimed at deepening the role of possible alterations of biomarkers in the pathophysiology of mood disorders that might lead to more focused and tailored treatments. The present study is a comprehensive review on these topics that seem to represent intriguing avenues for the development of real innovative therapeutic strategies of mood disorders.