Association between fatigue and depressive symptoms in persons with post-COVID-19 condition: a post hoc analysis.

OBJECTIVE: Post-COVID-19 Condition (PCC) is a prevalent, persistent and debilitating phenomenon occurring three or more months after resolution of acute COVID-19 infection. Fatigue and depressive symptoms are commonly reported in PCC. We aimed to further characterize PCC by assessing the relationship between fatigue and depressive symptom severity in adults with PCC. METHODS: A post hoc analysis was conducted on data retrieved from a randomized, double-blinded, placebo-controlled study evaluating vortioxetine for cognitive deficits in persons with PCC. We sought to determine the relationship between baseline fatigue [i.e. Fatigue Severity Scale (FSS) total score] and baseline depressive symptom severity [i.e. 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR-16) total score] in adults with PCC. RESULTS: The statistical analysis included baseline data from 142 participants. After adjusting for age, sex, education, employment status, history of major depressive disorder (MDD) diagnosis, self-reported physical activity, history of documented acute SARS-CoV-2 infection and body mass index (BMI), baseline FSS was significantly correlated with baseline QIDS-SR-16 (ß = 0.825, p = .001). CONCLUSION: In our sample, baseline measures of fatigue and depressive symptoms are correlated in persons living with PCC. Individuals presenting with PCC and fatigue should be screened for the presence and severity of depressive symptoms. Guideline-concordant care should be prescribed for individuals experiencing clinically significant depressive symptoms. Fatigue and depressive symptom severity scores were not pre-specified as primary objectives of the study. Multiple confounding factors (i.e. disturbance in sleep, anthropometrics and cognitive impairment) were not collected nor adjusted for in the analysis herein. TRIAL REGISTRATION: Unrestricted Research Grant from H. Lundbeck A/S, Copenhagen, Denmark. ClinicalTrials.gov Identifier: NCT05047952.

Spectral signatures of psilocybin, lysergic acid diethylamide (LSD) and ketamine in healthy volunteers and persons with major depressive disorder and treatment-resistant depression: A systematic review.

BACKGROUND: Electrophysiologic measures provide an opportunity to inform mechanistic models and possibly biomarker prediction of response. Serotonergic psychedelics (SPs) (i.e., psilocybin, lysergic acid diethylamide (LSD)) and ketamine represent new investigational and established treatments in mood disorders respectively. There is a need to better characterize the mechanism of action of these agents. METHODS: We conducted a systematic review investigating the spectral signatures of psilocybin, LSD, and ketamine in persons with major depressive disorder (MDD), treatment-resistant depression (TRD), and healthy controls. RESULTS: Ketamine and SPs are associated with increased theta power in persons with depression. Ketamine and SPs are also associated with decreased spectral power in the alpha, beta and delta bands in healthy controls and persons with depression. When administered with SPs, theta power was increased in persons with MDD when administered with SPs. Ketamine is associated with increased gamma band power in both healthy controls and persons with MDD. LIMITATIONS: The studies included in our review were heterogeneous in their patient population, exposure, dosing of treatment and devices used to evaluate EEG and MEG signatures. Our results were extracted entirely from persons who were either healthy volunteers or persons with MDD or TRD. CONCLUSIONS: Extant literature evaluating EEG and MEG spectral signatures indicate that ketamine and SPs have reproducible effects in keeping with disease models of network connectivity. Future research vistas should evaluate whether observed spectral signatures can guide further discovery of therapeutics within the psychedelic and dissociative classes of agents, and its prediction capability in persons treated for depression.

Impact of elevated body mass index (BMI) on cognitive functioning and inflammation in persons with post-COVID-19 condition: a secondary analysis.

BACKGROUND: Individuals who have recovered from the acute stage of SARS-CoV-2 infection may be at risk of developing post-COVID-19 condition (PCC), characterised by a spectrum of persisting, non-specific, and functionally impairing symptoms across multiple organ systems. Obesity has been implicated as a risk factor for PCC, mediated by chronic systemic inflammation. The foregoing has also been separately reported to mediate cognitive dysfunction in PCC. METHODS: This is a post-hoc analysis of a randomised, double-blinded, placebo-controlled clinical trial evaluating vortioxetine treatment for cognitive impairments in persons with PCC who received vortioxetine or placebo for eight weeks. This analysis comprises baseline data, examining the impact of BMI on cognitive functioning measured by the Digit Symbol Substitution Test (DSST) and Trails Making Tests (TMT)-A/B, as well as inflammation, via serum c-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). RESULTS: Complete data from 70 participants were statistically analysed and adjusted for age and sex. BMI was negatively correlated with performance on the DSST (ß = -0.003, p = 0.047), TMT-A (ß = -0.006, p = 0.025), and TMT-B (ß = -0.006, p = 0.002). BMI was positively correlated with serum CRP (unstandardized ß = 0.193, standardized ß = 0.612, p < 0.001) and ESR (ß = 0.039, p < 0.001) levels. CONCLUSION: We observed a significant negative correlation between BMI and cognitive functioning, and a significant positive correlation between BMI and inflammation in persons with PCC, suggesting a bidirectional interplay between BMI, PCC, and cognitive function; individuals with an elevated BMI may be at a greater risk of developing PCC and/or presenting with greater cognitive deficits mediated by chronic systemic inflammation.

Assessing the Effects of Metabolic Disruption, Body Mass Index and Inflammation on Depressive Symptoms in Post-COVID-19 Condition: A Randomized Controlled Trial on Vortioxetine.

INTRODUCTION: To date, there are no therapeutics that have gained regulatory approval by the United States Food and Drug Administration (FDA) for the treatment of post-COVID-19 condition (PCC), a debilitating condition characterized by cognitive impairment and mood symptoms. Additionally, persistent inflammation, metabolic dysfunction, and risks associated with an elevated body mass index (BMI) have been observed. Herein, we aimed to assess the efficacy of vortioxetine in improving depressive symptoms among individuals with PCC,  as modulated by inflammation, metabolic dysfunction, and BMI. METHODS: In this post-hoc analysis, we present preliminary data obtained from an 8-week randomized, double-blind, placebo-controlled trial. Participants included  adults aged 18 years and older residing in Canada who were experiencing symptoms of World Health Organization (WHO)-defined PCC. Recruitment began November 2021 and ended January 2023. Of the 200 participants enrolled, 147 were randomized (1:1) to receive vortioxetine (5-20 mg, n = 73) or placebo (n = 74) for daily treatment under double-blind conditions. The primary outcome measure was the change from baseline to endpoint in the 16-Item Quick Inventory of Depressive Symptomatology Self-Report Questionnaire (QIDS-SR-16). RESULTS: Our findings revealed significant effects for time (χ2 = 9.601, p = 0.002), treatment (χ2 = 9.135, p = 0.003), and the treatment × time × CRP × TG-HDL × BMI interaction (χ2 = 26.092, p < 0.001) on PCC-related depressive symptoms in the adjusted model. Moreover, the between-group analysis showed a significant improvement with vortioxetine at endpoint as compared to placebo (mean difference = - 5.41, SEM = 1.335, p < 0.001). CONCLUSION: Overall, vortioxetine significantly improved depressive symptoms among participants with PCC in the adjusted model. Notably, individuals with baseline markers of increased inflammation, metabolic disruption, and elevated BMI exhibited a more pronounced antidepressant effect at endpoint. TRIAL REGISTRATION NUMBER: NCT05047952 (ClinicalTrials.gov).

Brain-derived neurotrophic factor Val66Met and CYP2B6 polymorphisms as predictors for ketamine effectiveness in patients with treatment-resistant depression.

BACKGROUND: Converging lines of evidence indicate that ketamine is a rapid antidepressant for individuals with treatment-resistant depression. Hitherto, no reliable a priori predictors of ketamine response have been reported. Pharmacogenetic biomarkers have yielded mixed results regarding potential candidate genes associated with ketamine's biochemistry as reliable predictors of response. AIMS: No studies have examined the effects of Val66Met and CYP2B6 genotypes on patients receiving repeated infusions of intravenous ketamine. METHODS: In all, 85 participants with major depressive disorder who had previously received four infusions of intravenous ketamine were recruited to the foregoing study. Buccal swabs were collected and genotype variants across the Val66Met and CYP2B6 genes were analyzed. A repeated measures mixed linear model was used to assess change in depressive symptoms, suicidality, and anxiety, correcting for sex and age. Multiple regression was run to determine whether these genetic markers were associated with treatment efficacy for depressive severity, suicidal ideation, anxiolytic response, and degree of dissociation to intravenous ketamine. RESULTS: Participants experienced significant overall reductions in depression, suicide, and anxiety. Overall, 25% met the response criteria and 15% met the remission criteria. However, Val66Met and CYP2B6 did not significantly predict changes in symptoms of depression, suicide, anxiety, or average dissociation. CONCLUSIONS: This study contributes to the growing literature that ketamine efficacy is unlikely to be predicted by single genes, and a pleiotropic approach may likely be necessary for developing reliable predictors of clinical benefits.

Impacts of metabolic disruption, body mass index and inflammation on cognitive function in post-COVID-19 condition: a randomized controlled trial on vortioxetine.

BACKGROUND: Post-COVID-19 Condition (PCC), as defined by the World Health Organization (WHO), currently lacks any regulatory-approved treatments and is characterized by persistent and debilitating cognitive impairment and mood symptoms. Additionally, metabolic dysfunction, chronic inflammation and the associated risks of elevated body mass index (BMI) have been reported. In this study, we aim to investigate the efficacy of vortioxetine in improving cognitive deficits in individuals with PCC, accounting for the interaction of metabolic dysfunction, elevated inflammation and BMI. METHODS: This is a post-hoc analysis of an 8-week randomized, double-blind, placebo-controlled trial that was conducted among adults aged 18 years and older living in Canada who were experiencing WHO-defined PCC symptoms. The recruitment of participants began in November 2021 and concluded in January 2023. A total of 200 individuals were enrolled, where 147 were randomized in a 1:1 ratio to receive either vortioxetine (5-20 mg, n = 73) or placebo (n = 74) for daily treatment under double-blind conditions. The primary outcome measure was the change in the Digit Symbol Substitution Test (DSST) score from baseline to endpoint. RESULTS: Our findings showed significant effects for time (χ2 = 7.771, p = 0.005), treatment (χ2 = 7.583, p = 0.006) and the treatment x time x CRP x TG-HDL x BMI interaction (χ2 = 11.967, p = 0.018) on cognitive function. Moreover, the between-group analysis showed a significant improvement with vortioxetine at endpoint (mean difference = 0.621, SEM = 0.313, p = 0.047). CONCLUSION: Overall, vortioxetine demonstrated significant improvements in cognitive deficits among individuals with baseline markers of metabolic dysfunction, elevated inflammation and higher BMI at endpoint as compared to placebo. TRIAL REGISTRATION: NCT05047952 (ClinicalTrials.gov; Registration Date: September 17, 2021).

The efficacy of zuranolone in postpartum depression and major depressive disorder: a review & number needed to treat (NNT) analysis.

INTRODUCTION: Major depressive disorder (MDD) is a common and debilitating mental illness. Postpartum depression (PPD) impacts women globally and is one of the most common complications of childbirth that is underdiagnosed and undertreated, adversely impacting the mental health of women, children, and partners.Available antidepressant medications require weeks to months before showing effect. In this setting, zuranolone, an oral neuroactive steroid and a positive allosteric modulator of GABAA receptors, is an attractive alternative as a rapid-acting antidepressant treatment. AREAS COVERED: This article reviews zuranolone (SAGE217), focusing on available clinical studies in individuals with PPD and MDD. This paper adds to the extant literature by presenting the efficacy data as Number Needed to Treat (NNT) to facilitate indirect comparisons with other antidepressants. EXPERT OPINION: Zuranolone is a novel rapid-acting (i.e. two week course) oral antidepressant for the treatment of adults with PPD with ongoing clinical trials evaluating its efficacy in adults with MDD. Zuranolone is well tolerated with no significant safety concerns in any clinical trials completed to date. Zuranolone will be scheduled by the Drug Enforcement Agency (DEA).

A comparison between psilocybin and esketamine in treatment-resistant depression using number needed to treat (NNT): A systematic review.

BACKGROUND: Inadequate outcomes with monoamine-based treatments in depressive disorders are common and provide the impetus for mechanistically-novel treatments. Esketamine is a proven treatment recently approved for adults with Treatment-Resistant Depression (TRD) while psilocybin is an investigational treatment. Translation of the clinical meaningfulness for these foregoing agents in adults with TRD is required. Herein we evaluate the Number Needed to Treat (NNT) and Harm (NNH) of esketamine and psilocybin in adults with TRD. METHODS: We conducted a systematic review of randomized controlled trials, comparing the clinical efficacy of oral psilocybin to the co-commencement of intranasal esketamine with an oral antidepressant in adults with TRD. RESULTS: 25 mg psilocybin had a significant reduction in depressive symptoms at 21-days post-dose, the NNT was 5 [95 % CI = 3.1, 18.5]. Psilocybin-induced nausea had a significant NNH = 5. Fixed-dosed esketamine at 56 mg and 84 mg had a significant effect at 28-days post-dose, (NNT of 7 [95 % CI56mg = 3.5, 46.7], [95 % CI84mg = 3.6, 142.2]). Esketamine-induced headache, nausea, dizziness, and dissociation had NNHs <10. LIMITATIONS: The preliminary results may only reflect a small portion of the patient population. These results require replication and longer term studies investigating maintenance therapy. CONCLUSION: Relatively few pharmacologic agents are proven safe and effective in adults with TRD. NNT estimates for investigational psilocybin and esketamine in TRD indicate clinical meaningfulness. The NNH profile for both aforementioned agents is clinically acceptable. Our results underscore the clinical relevance of these treatment options in adults with TRD.

Clinical efficacy and safety of Zuranolone (SAGE-217) in individuals with major depressive disorder.

Major depressive disorder (MDD) is a common mental disorder with a high rate of morbidity and mortality. Dysfunctional signaling of gamma-aminobutyric acid (GABA) has been implicated in some studies in the etiology of MDD. Zuranolone (SAGE-217) is a novel, oral neuroactive steroid and an investigational positive allosteric modulator of synaptic and extrasynaptic GABAA receptors. Herein, we aimed to evaluate the efficacy and safety of Zuranolone in individuals with MDD. We reviewed seven studies including 1662 participants with MDD. Zuranolone was investigated as an oral, once-daily, 14-day treatment course. The results of our synthesis indicate that the antidepressant effects of Zuranolone are rapid, clinically meaningful, and replicated across multiple randomized clinical trials. In addition to replicated efficacy, Zuranolone is associated with an acceptable level of treatment-emergent adverse events and discontinuation without serious adverse events. It is believed that Zuranolone's antidepressant effects arise from its ability to enhance inhibitory GABAergic signaling by increasing synaptic and extrasynaptic GABAA activity and regulation of GABAA receptor expression. Taken together, preliminary evidence suggests the potential for antidepressant effects of Zuranolone. Zuranolone has been approved by FDA for postpartum depression, and is showing efficacy in major depressive disorder. Future research vistas should seek to determine the durability of this treatment approach as well as its effects on domain-specific outcomes (e.g., anhedonia, circadian rhythm, arousal systems) along with application in other diagnostic entities (e.g., bipolar depression).

Glucagon-like peptide 1 (GLP-1) receptor agonists as a protective factor for incident depression in patients with diabetes mellitus: A systematic review.

Glucagon-like peptide 1 (GLP-1) receptor agonists are widely used for glycemic control in patients with diabetes mellitus (DM) and are primarily indicated for type 2 diabetes mellitus (T2DM). GLP-1 receptor agonists have also been shown to have neuroprotective and antidepressant properties. Replicated evidence suggests that individuals with DM are significantly more likely to develop depression. Herein, we aim to investigate whether GLP-1 receptor agonists can be used prophylactically on patients with DM to lower the risk of incident depression. We conducted a systematic search for English-language articles published on the PubMed/MEDLINE, Scopus, Embase, APA, PsycInfo, Ovid and Google Scholar databases from inception to June 6, 2022. Four retrospective observational studies were identified that evaluated the neuroprotective effects of GLP-1 receptor agonists on incident depression in patients with DM. We found mixed results with regards to lowering the risk of incident depression, with two studies demonstrating a significant reduction in risk and two studies showing no such effect. A single study found that dulaglutide may lower susceptibility to depression. Our results were limited by high interstudy heterogeneity, paucity of literature, and lack of controlled trials. While we did not find evidence of GLP-1 receptor agonists significantly lowering risk of incident depression in patients with DM, promising neuroprotective data presented in two of the included papers, specifically on dulaglutide where information is scarce, provide the impetus for further investigation. Future research should focus on better elucidating the neuroprotective potential of different classes and doses of GLP-1 receptor agonists using controlled trials.

The Role of Ketamine in the Treatment of Bipolar Depression: A Scoping Review.

Bipolar depression remains a clinical challenge with a quarter of patients failing to respond to initial conventional treatments. Although ketamine has been extensively studied in unipolar depression, its role in bipolar disorder remains inconclusive. The aim of our scoping review was to comprehensively synthesize the current clinical literature around ketamine use in bipolar depression. A total of 10 clinical studies (5 randomized controlled trials and 5 open label studies) were selected. The preliminary evidence, albeit weak, suggests that ketamine is a promising treatment and calls for further interest from the research community. Overall, ketamine treatment appeared to be tolerable with minimal risk for manic/hypomanic switching and showed some effectiveness across parameters of depression and suicidality. Moreover, ketamine is a potential treatment agent in patients with treatment-resistant bipolar depression with promising data extracted from extant controlled trials and real-world effectiveness studies. Future studies are needed to identify ketamine's role in acute and maintenance treatment phases of bipolar depression. Moreover, future researchers should study the recurrence prevention and anti-suicidal effects of ketamine in the treatment of bipolar depression.

Real-world effectiveness of repeated intravenous ketamine infusions for treatment-resistant depression in transitional age youth.

BACKGROUND: Ketamine is an emerging treatment for treatment-resistant depression (TRD) associated with rapid and robust improvements in depressive symptoms and suicidality. However, the efficacy and safety of ketamine in transitional age youth (TAY; age 18-25) populations remains understudied. METHODS: In this retrospective analysis, TAY patients (n = 52) receiving ketamine for TRD were matched for sex, primary diagnosis, baseline depression severity, and treatment resistance with a general adult (GA) sample (age 30-60). Patients received four ketamine infusions over 2 weeks (0.5-0.75 mg/kg over 40 min). The primary outcome was the change in Quick Inventory of Depressive Symptomatology Self-Report 16-item (QIDS-SR16) over time. Secondary outcomes were changes in QIDS-SR16 suicidal ideation (SI) item, anxiety (Generalized Anxiety Disorder 7-item (GAD-7)), and adverse effects (ClinicalTrials.gov: NCT04209296). RESULTS: A significant main effect of infusions on reduction of total QIDS-SR16 (p < 0.001), QIDS-SR16 SI (p < 0.001), and GAD-7 (p < 0.001) scores was observed in the TAY group with moderate effect sizes, indicative of clinically significant improvements in depression, anxiety, and suicidality. There were no significant differences between TAY and GA groups on these measures over time, suggesting comparable improvements in both groups. Safety and tolerability outcomes were comparable between groups with only mild, transient adverse effects observed. CONCLUSION: Ketamine was associated with comparable clinical benefits, safety, and tolerability in a TAY sample as compared to a matched GA TRD sample.

Efficacy, safety, and tolerability of ulotaront (SEP-363856, a trace amine-associated receptor 1 agonist) for the treatment of schizophrenia and other mental disorders: a systematic review of preclinical and clinical trials.

INTRODUCTION: Schizophrenia is a mental illness that can disrupt emotions, perceptions, and cognition and reduce quality of life. The classical approach to treat schizophrenia is to use typical and atypical antipsychotics; however, limitations include low efficacy in mitigating negative symptoms and cognitive dysfunctions and a range of adverse effects. Evidence has accumulated on trace amine-associated receptor 1 (TAAR1) as a novel therapeutic target for treating schizophrenia. This systematic review investigates the available evidence on a TAAR1 agonist, ulotaront, as a treatment for schizophrenia. METHODS: A systematic search was conducted on PubMed/MEDLINE and Ovid databases for English-published articles from inception to 18 December 2022. The literature focusing on the association between ulotaront and schizophrenia was evaluated based on an inclusion/exclusion criterion. Selected studies were assessed for the risk of bias, using the Cochrane Collaboration tool, and summarized in a table to generate discussion topics. RESULTS: Three clinical, two comparative, and five preclinical studies examining ulotaront's pharmacology, tolerability and safety, and/or efficacy were identified. Results indicate that ulotaront has a differing adverse effect profile from other antipsychotics, may mitigate metabolic-related adverse effects commonly associated with antipsychotics, and may be effective for treating positive and negative symptoms. CONCLUSIONS: Findings from the available literature present ulotaront as a potential and promising alternative treatment method for schizophrenia. Despite this, our results were limited due to the lack of clinical trials on ulotaront's long-term efficacy and mechanisms of action. Future research should focus on these limitations to elucidate ulotaront's efficacy and safety for the treatment of schizophrenia and other mental disorders with similar pathophysiology.

COVID-19 vaccination for the prevention and treatment of long COVID: A systematic review and meta-analysis.

Empirical evidence addressing the association between SARS-CoV-2 vaccination and long COVID would guide public health priorities and inform personal health decisions. Herein, the co-primary objectives are to determine the differential risk of long COVID in vaccinated versus unvaccinated patients, and the trajectory of long COVID following vaccination. Of 2775 articles identified via systematic search, 17 were included, and 6 were meta-analyzed. Meta-analytic results determined that at least one vaccine dose was associated with a protective effect against long COVID (OR 0.539, 95% CI 0.295-0.987, p = 0.045, N = 257 817). Qualitative analysis revealed that trajectories of pre-existing long COVID following vaccination were mixed, with most patients reporting no changes. The evidence herein supports SARS-CoV-2 vaccination for the prevention of long COVID, and recommends long COVID patients adhere to standard SARS-CoV-2 vaccination schedules.

Oral ketamine for depression: An updated systematic review.

Objectives: Ketamine is a glutamate N-methyl-D-aspartate receptor antagonist that can be used to treat major depressive disorder by single or repeated infusions. However, the accessibility and scalability of oral ketamine make it preferred over intravenous ketamine. In this systematic review, we aim to evaluate the efficacy, tolerability, and safety of oral ketamine, esketamine and r-ketamine for unipolar and bipolar depression. Materials and methods: Electronic databases were searched from inception to September 2022 to identify relevant articles. Results: Twenty-two studies, including four randomized clinical trials (RCTs), one case series, six case reports, five open-label trials and six retrospective chart review studies involving 2336 patients with depression were included. All included studies reported significant improvement following ketamine administration. Ketamine was well tolerated without serious adverse events. However, RCTs had a high risk of bias due to analysis methods and adverse events monitoring. Ketamine dosage varied from 0.5 to 1.25 mg/kg. The frequency of administration was daily to monthly. Several important limitations were identified, most notably the small number of RCTs. Conclusions: Taken together, preliminary evidence suggests the potential for antidepressant effect of oral ketamine. However, further research with large sample size and long follow-up period is needed to better determine the antisuicidal effect and efficacy in treatment-resistant depression.

The bidirectional association of nonalcoholic fatty liver disease with depression, bipolar disorder, and schizophrenia.

Nonalcoholic fatty liver disease (NAFLD) is a complex metabolic-inflammatory disease associated with poor outcomes and decreased quality of life. NAFLD is overrepresented in patients with psychiatric disorders like depression, bipolar disorder, and schizophrenia; however, a comprehensive review on NAFLD and psychiatric disorders remains to be delineated. This review endeavors to investigate the association of NAFLD with psychiatric disorders, including shared pathogenesis and future clinical derivatives. Extant literature suggests that patients with psychiatric disorders (in particular, mood disorders) are more susceptible to the development of NAFLD due to multiple reasons, including but not limited to hypothalamic-pituitary-adrenal axis dysregulation, metabolic syndrome, and chronic perceived stress. Moreover, the clinical manifestations of mood disorders (e.g., anhedonia, psychomotor retardation, lifestyle modification, etc.), and potentially long-term treatment with weight-gaining agents, differentially affect these patients, making them more prone to NAFLD. Considering the increased morbidity associated with both mood disorders and NAFLD, our review recommends regular screenings for NAFLD in select patients with mood disorders exhibiting signs of increased risk (i.e., obesity, metabolic syndrome, diabetes, or family history of NAFLD) for better diagnosis and holistic care of both potentially interrelated conditions.

Changes in insulin resistance following antidepressant treatment mediate response in major depressive disorder.

BACKGROUND: Insulin resistance (IR) is a potential predictor of antidepressant treatment response. AIMS: We assess changes in IR after antidepressant treatment and whether these changes have any effect on treatment response. Also, to see whether changes in IR mediates relationship between C-reactive protein (CRP) and antidepressant efficacy. METHODS: This is a secondary analysis of an 8-week, open-label clinical trial with 95 adults experiencing a major depressive episode. Response to vortioxetine was measured using the Montgomery-Åsberg Depression Rating Scale (MADRS). Generalized estimating equation models were utilized for this intent-to-treat analysis. RESULTS: When adjusted for age, sex, and body mass index, there was a significant increase in IR following treatment in the overall sample (p = 0.035). This finding was detected in treatment non-responders (p = 0.019), whereas it was not observed in responders (p = 0.329). Mediation analysis revealed that change in IR during treatment was responsible for change in MADRS as well as the relationship between baseline CRP and treatment response. CONCLUSIONS: Exacerbation of IR during antidepressant treatment mediated non-response. Conversely in treatment responders IR reduced. Like previous studies, baseline CRP moderated treatment response. This relationship was also mediated by changes in IR. These findings further elucidate the role of IR in terms of antidepressant response as well as potentially explain inflammation's relationship with the latter.

Real-world effectiveness of repeated ketamine infusions for treatment-resistant bipolar depression.

BACKGROUND: Clinical trials have demonstrated rapid antidepressant effects with intravenous (IV) ketamine for major depressive disorder, with relatively less research specifically for bipolar depression. Herein, we describe the real-world effectiveness of repeated ketamine infusions for treatment-resistant bipolar depression. METHODS: This study was conducted in a community clinic in Mississauga, Ontario (Canadian Rapid Treatment Centre of Excellence; Braxia Health). In this observational study (NCT04209296), patients with treatment-resistant bipolar I/II depression (n = 66) received four sub-anesthetic doses of IV ketamine (0.5-0.75 mg/kg) over a two-week period. Symptoms of depression, suicidality, anxiety, and functioning were assessed with validated self-report measures. RESULTS: Statistically and clinically significant antidepressant effects were observed in the overall sample, as measured by the Quick Inventory for Depression Symptomatology-Self Report-16 (QIDS-SR16 ) with further reductions in depressive symptoms observed after each subsequent infusion (n = 66; mean QIDS-SR16 reduction of 6.08+/-1.39; p < 0.0001). Significant reductions of suicidal thoughts (QIDS-SR16 -Suicide Item) and anxiety (Generalized Anxiety Disorder-7) were also observed with functional improvements on the Sheehan Disability Scale (p < 0.0001 on all measures). Moreover, the response rate (QIDS-SR16 total score decrease ≥50% from baseline) was 35% and remission rate (QIDS-SR16 total score ≤5) was 20% after four infusions. Infusions were generally well tolerated with treatment-emergent hypomania observed in only three patients (4.5%) with zero cases of mania or psychosis. CONCLUSIONS: Real-world effectiveness of IV ketamine for bipolar depression was observed. Repeated doses were associated with greater symptom reduction and adequate tolerability.

Biomarkers of ketamine's antidepressant effect: An umbrella review.

Ketamine is a NMDA receptor antagonist that has a rapid acting antidepressant effect with high efficacy in treatment-resistant patients. Ketamine is a beneficial antidepressant for many individuals with depression, but not all of the patients respond, and some even exhibit symptom deterioration. The discovery of repeatable and mechanistically relevant biomarkers would address a major gap in treatment response prediction. Numerous potential peripheral biomarkers have been reported, but their current utility is unclear. We conducted an umbrella review to evaluate the biomarkers of ketamine's antidepressant effect in individuals with depression. PubMed and copus were searched using terms appropriate to each area of research, from their inception until July 2022. Five systematic reviews and meta analyses including 108 studies with 4912 participants were included. Blood-based and neuroimaging biomarkers were investigated. The results of this review indicate that ketamine can produce an anti-inflammatory effect and decrease at least one inflammatory marker following administration. Data from neuroimaging studies demonstrated that the cingulate cortex is the key locus of ketamine's action. The majority of the blood-based, neuroimaging, and neurophysiological investigations reviewed herein indicate ketamine induced normalization of major depressive disorder pathogenesis via synaptic plasticity and functional connectivity. Currently, no biomarker/biosignature is sufficiently validated for clinical utility, but several are promising. Now that ketamine is more widely available, biomarker discovery and replication should be attempted in larger, real-world populations.