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A potential role for leptin in the pathophysiology of bipolar disorder (BD) has been proposed. We recently investigated the effects of the tumor necrosis factor-alpha (TNF-α) antagonist infliximab in individuals with bipolar depression. Leptin is known to interact with the TNF-α system. Herein, we aimed to explore infliximab's effects on leptin and its relationship with brain structure and function. Sixty adults with bipolar depression were enrolled in this randomized, double-blind, 12-week clinical trial of adjunctive infliximab (n = 29) and saline control (n = 31), which were administered intravenously at weeks 0, 2, and 6. Plasma concentrations of leptin, TNF-α and soluble TNF receptors (sTNFR) 1 and 2 were assessed at weeks 0, 2, 6, and 12. We observed a significant decrease in leptin levels in infliximab-treated patients, relative to placebo. Infliximab treatment also significantly reduced TNF-α and sTNFR2, but not sTNFR1 levels. Changes in sTNR2 levels at week 6 significantly determined changes in leptin at week 12 in infliximab-, but not placebo-treated participants. Improvements in verbal memory and increases in global cortical volume were associated with reduction in leptin levels in the treatment group. Mediation analysis indicated that cognitive improvement in infliximab-treated patients was mediated by reductions in leptin levels, which in its turn were determined by decreases in sTNR2 levels. In conclusion, infliximab treatment reduced plasma leptin levels in individuals with BD, through modulation of sTNFR2. Decreases in leptin signaling were associated with an increase in global cortical volume and better performance in a verbal memory task., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Antidepressant pharmacotherapy dominates current treatment in psychiatry, including treatment for major depressive disorder (MDD). However, the current trial-and-error process of medication selection contributes to treatment failure and unnecessarily exposes patients to lengthy and insufficient treatment trials. Notably, improvements in measures of cognition have been demonstrated to occur early during treatment and prior to improvements in clinical state. Cognitions have been categorized based on emotional valence (i.e., cold versus hot cognitions). Cold cognitions describe cognitive operations that are relevant to the processing of non-emotional information. The current analysis investigates whether early changes in cold cognition can predict response after 8 weeks of vortioxetine treatment in adults with MDD. This was secondary analysis of an 8-week, open-label study. Cognition was assessed at week 0 and week 2 to measure early cognitive change. Depressive symptom severity was assessed at week 0 and week 8 to measure treatment response. Eighty-one subjects were analyzed using binomial logistic regression models. Early change in cognition was a non-significant predictor of response (p = 0.845, SE = 0.599, OR = 1.124), which may have resulted from high data variability. The overall predictive accuracy of the model was low (sensitivity = 37.5%, specificity = 89.8%, PPV = 70.6%, NPV = 68.8%). Future studies should include larger samples and stratify patients based on potentially moderating variables, such as baseline cognitive impairment and occupation. Stratification would likely produce more homogenous samples, reducing the amount of variability observed for early cognitive change., Competing Interests: Declaration of Competing Interest Roger S. McIntyre is a consultant to speak on behalf for, and/or has received research support from Lundbeck, Janssen, Shire, Purdue, Pfizer, Otsuka, Allergan, Takeda, Neurocrine, Sunovion, Stanley Medical Research Institute, and CIHR/GACD/Chinese National Natural Research Foundation. All other authors have no conflicts of interest to disclose., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: It is well established that deficits in motivation, reward, and cognition are common during and in between syndromal episodes of depression as part of Major Depressive Disorder (MDD). Informed by evidence indicating functional and structural interconnectivity between cognitive and reward brain circuits, we preliminarily evaluate the association between measures of cognitive performance and reward/motivation., Methods: This is a post-hoc analysis of a primary study (i.e. the THINC-it sensitivity to change study). Adults (18-65 years of age) meeting DSM-5 criteria for MDD, single-episode or recurrent confirmed by M.I.N.I. with moderate severity or greater (i.e. Montgomery Asberg Depression Rating Scale ≥20). All eligible subjects received vortioxetine 10-20 mg open-label for 8 weeks. The Effort Expenditure Reward Task (EEfRT) was the principal measure of motivation and reward. We directly compare the effects of cognitive measures and depressive symptoms on effort-based decision-making using the THINC-it composite score and MADRS total score., Results: Twenty-one participants with MDD (Mean age = 38.47, SD = 12.85) and 20 healthy volunteers (Mean age = 41.50, SD = 14.21) completed the optional EEfRT task. Amongst individuals with MDD, performance in processing speed, executive function (i.e. Trails B) and overall composite cognitive score was positively associated with the proportion of hard-task choices in the high reward condition (i.e. greater reward valuation). Across both groups, a greater probability (χ 2  = 1.137) and magnitude of reward (χ 2  = 0.045) was associated with increased effort (i.e. choosing the hard task more frequently). Using fully factored GEE models, we observed a positive association between performance on the Trails test (β = 2.223, SE = 0.928, p = 0.017) as well as the composite score (β = 0.978, SE = 0.0.459, p = 0.033), and greater effort for high rewards. In addition, it was observed that a positive association (i.e. greater effort for reward in higher probability) was observed with depressive symptoms and overall cognitive measures., Conclusion: Herein, we observed that an association exists between overall cognitive function, notably processing speed and executive function and reward function. Specifically, a greater effort for hard task rewards (using the EEfRT task) was manifested in individuals exhibiting higher levels of cognitive performance in a well-characterized sample of MDD treated with Vortioxetine., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Cognitive dysfunction is a symptomatic domain identified across many mental disorders. Cognitive deficits in individuals with major depressive disorder (MDD) contribute significantly to occupational and functional disability. Notably, cognitive subdomains such as learning and memory, executive functioning, processing speed, and attention and concentration are significantly impaired during, and between, episodes in individuals with MDD. Most antidepressants have not been developed and/or evaluated for their ability to directly and independently ameliorate cognitive deficits. Multiple interacting neurobiological mechanisms (eg, neuroinflammation) are implicated as subserving cognitive deficits in MDD. A testable hypothesis, with preliminary support, posits that improving performance across cognitive domains in individuals with MDD may improve psychosocial function, workplace function, quality of life, and other patient-reported outcomes, independent of effects on core mood symptoms. Herein we aim to (1) provide a rationale for prioritizing cognitive deficits as a therapeutic target, (2) briefly discuss the neurobiological substrates subserving cognitive dysfunction, and (3) provide an update on current and future treatment avenues.

Background: The aim of this study was to examine the role of perceived sleep quality in predicting subjective as well as objective cognitive function in adults with major depressive disorder (MDD)., Methods: Adults with recurrent MDD (n = 100) experiencing a major depressive episode of at least moderate severity and age-, sex-, and education-matched healthy controls (HC) (n = 100) were recruited to participate in a clinical trial validating the THINC-integrated tool (THINC-it; NCT02508493) for cognitive function. The THINC-it includes subjective and objective measures of cognitive function. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI)., Results: Compared with HC, individuals with MDD reported significantly poorer sleep quality, as assessed by domain and global PSQI scores (all P values <.05). Both perceived sleep quality ( P < .001) and depression severity (P = .002) were found to independently predict impairments in subjective cognitive performance. Only perceived sleep quality predicted objective cognitive impairments (P = .017). Exploratory mediation analysis revealed depression severity to be a partial mediator of the relationship between perceived sleep quality and subjective cognitive performance (95% confidence interval [CI]: -0.56, -0.33)., Conclusions: The results indicate that the subjective and objective cognitive impairments are differentially related to perceived sleep quality and depression severity and emphasize the importance of treating sleep disturbances in MDD.

Background: Despite the widespread use of antidepressants in clinical practice, the current trial-and-error approach to medication selection contributes to treatment failure and underscores the need to identify reliable predictors of antidepressant response. Since changes in measures of cognition have been reported to occur early in treatment and prior to improvements in overall mood symptoms, the present review aims to determine whether early changes in measures of cognition can predict response in individuals with MDD., Methods: A systematic review of studies evaluating early cognitive change as a predictor of later treatment response in MDD was conducted using PubMed/Medline, Embase and PsychINFO., Results: A total of seven articles were identified. The available evidence suggests the early changes in cognition may predict treatment response in individuals with MDD. This was shown across antidepressant classes (i.e., SSRIs, SNRIs, NRIs, melatonergic antidepressants) and forms of therapy (i.e., pharmacotherapy, rTMS). The results depict an emerging trend towards early changes in facial emotion recognition (i.e., a hot cognitive process) as a predictor of treatment outcome., Limitations: Our qualitative analysis reflects a very limited number of studies. Moreover, there was significant heterogeneity in the evaluation of cognition across studies. Future research should aim to parse out this heterogeneity by evaluating the relative predictive value of different measures of cognition., Conclusion: The identification of reliable early treatment predictors of antidepressant response would be clinically significant, enabling clinicians to more accurately evaluate the efficacy of selected treatment avenues., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background and Objectives: This study evaluated the association between self-reported anxiety and objective/subjective measures of cognitive performance in adults with Major Depressive Disorder (MDD)., Methods: Acutely depressed subjects with recurrent MDD (n = 100) and age-, sex-, and education-matched healthy controls (HC; n = 100) between the ages of 18 and 65 completed the cross-sectional validation study of the THINC-integrated tool (THINC-it; ClinicalTrials.gov: NCT02508493). Objective cognitive performance was assessed using the THINC-it, and subjective cognitive impairment with the Perceived Deficits Questionnaire for Depression-5-item. Subjects also completed the Generalized Anxiety Disorder-7-item (GAD-7) questionnaire., Results: Subjects with MDD reported significantly more anxiety symptoms, as assessed by the GAD-7, compared to HC (p < 0.001). Linear regression analysis determined that anxiety symptoms significantly accounted for 70.4% of the variability in subjective cognitive impairment, adjusting for depression severity. Moreover, subjects' ratings of the difficulties caused by their anxiety were reported as significantly more severe among subjects with MDD when compared to HC (p < 0.001). Likewise, greater self-reported difficulties with anxiety significantly predicted 57.8% of the variability in subjective cognitive impairment, adjusting for depression severity. Neither anxiety symptoms nor impairment due to anxiety symptoms predicted objective cognitive performance., Limitations: Subjects were not prospectively verified to have a clinical diagnosis of GAD. Rather, this study examined the relationships between symptoms of generalized anxiety, assessed using a brief screening tool, and subjective and objective cognitive function., Conclusions: Results from the current study indicate that adults with MDD and high levels of self-reported anxiety are significantly more likely to report experiencing subjective cognitive dysfunction., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: The burden of illness associated with bipolar disorder (BD) warrants early pre-emption/prevention. Prediction models limited to psychiatric phenomenology have insufficient predictive power. Herein, we aimed to evaluate whether the presence of overweight/obesity is associated with greater cognitive decline in individuals at high risk (HR) or ultra high risk (UHR) for BD., Methods: We conducted a retrospective analysis to investigate the moderational role of body mass index (BMI) on measures of cognitive function. Subjects between the ages of 8 and 28 years with a positive family history of BD were compared to age-matched controls with a negative family history of BD. Subjects with at least one biological parent with bipolar I/II disorder were further stratified into UHR or HR status by the presence or absence, respectively, of subthreshold hypomanic, major depressive, attenuated psychotic, and/or attention-deficit/hyperactivity disorder symptoms., Results: A total of 36 individuals at HR for BD, 33 individuals at UHR for BD, and 48 age-matched controls were included in the analysis. Higher BMI was significantly associated with lower performance on measures of processing speed (i.e. Brief Assessment of Cognition in Schizophrenia-symbol coding: r=-.186, P=.047) and attention/vigilance (i.e. Continuous Performance Test-Identical Pairs: r=-.257, P=.006). There were trends for negative correlations between BMI and measures of working memory (i.e. Wechsler Memory Scale-III Spatial Span: r=-0.177, P=.059) and overall cognitive function (i.e. Measurement and Treatment Research to Improve Cognition in Schizophrenia composite score: r=-.157, P=.097). Negative associations between BMI and cognitive performance were significantly stronger in the UHR group than in the HR group, when compared to controls., Conclusions: Individuals at varying degrees of risk for BD exhibit greater cognitive impairment as a function of co-existing overweight/obesity. Prediction models for BD may be substantively informed by including information related to overweight/obesity and, perhaps, other general medical conditions that share pathology with BD. Our findings herein, as well as the salutary effects of bariatric surgery on measures of cognitive function in obese populations, provide the rationale for hypothesizing that mitigating excess weight in individuals at elevated risk for BD may forestall or prevent declaration of illness., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose of Review: Cognitive dysfunction in major depressive disorder (MDD) is common, pervasive across multiple subdomains of cognitive function, and is a principle determinant of health outcomes from patient, provider, and societal perspectives. The overarching aim herein is to provide rationale for the evaluation, measurement, and specific treatment of cognitive function in adults with MDD., Recent Findings: Evidence indicates that cognitive dysfunction in MDD is a critical mediator of workplace disability. Systematic evaluation and measurement of cognitive function is warranted. All individuals with MDD should be evaluated for both objective and subjective cognitive dysfunction. Although differences between antidepressants in overall antidepressant efficacy are not consistent, unequivocal differences in improving measures of cognitive function are noted with evidence indicating that vortioxetine has multidomain cognitive benefits, whereas duloxetine has replicated evidence of improving measures of acquisition and recall (i.e. memory)., Summary: The probability of functional recovery in MDD is likely to increase with interventions that specifically target and improve measures of cognitive function. Clinicians are encouraged to evaluate patients using a validated measure (e.g. the THINC-it tool); prevention of cognitive impairment in MDD is a critical therapeutic priority. Vortioxetine and duloxetine benefit measures of cognitive function in MDD. Preliminary evidence of beneficial effects on cognitive emotional processing are reported with ketamine.

Background: Cognitive deficits are prevalent in bipolar disorder and are a significant contributor to negative patient-reported outcomes. Herein we conducted a pilot study of repetitive transcranial magnetic stimulation (rTMS) to improve cognitive function in adults with bipolar disorder.Methods: The study was a triple-blinded, randomized, placebo-control trial. Participants (aged 18 to 60) with a diagnosis of DSM-5-defined bipolar disorder (I or II) were recruited and randomized (N=36) to receive either a sham treatment (n=20) or an active rTMS treatment (n=16). Patients completed the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) at baseline and 1-2 weeks after the rTMS intervention.Results: A significant group by time interaction was observed in the Hopkins Verbal Learning Test-Revised (HVLT-R), (F (1, 34) = 17.0, p < 0.001, partial η2 = 0.33). Post-hoc analysis revealed that although both groups did not significantly differ at baseline (p = 0.58), patients in the active rTMS group significantly improved following neurostimulation (p = 0.02) for HVLT-R. Moreover, within-subject analysis indicated that the active rTMS group significantly improved in score from pre-treatment to post-treatment (p < 0.001), while the sham group did not improve (p = 0.94) for HVLT-R. No significant differences were seen in the other cognitive measures.Limitations: The study was conducted in a small sample .Conclusion: This pilot study, which was intended to establish feasibility, suggests that rTMS may offer benefit in select domains of cognitive functioning in bipolar disorder. None of the measures across subdomains revealed a dyscognitive effect. [ABSTRACT FROM AUTHOR]

• Research in BD has been hindered by the lack of a unifying disease model • We propose that dysregulated energy expenditure is a primary cause of BD • We review the evidence on the relevance of energy homeostasis for brain function • The behavioral and mechanistic correlates of energy dysregulation are discussed • We propose the phenotypes and longitudinal progression resulting from this process Advances in the understanding and management of bipolar disorder (BD) have been slow to emerge. Despite notable recent developments in neurosciences, our conceptualization of the nature of this mental disorder has not meaningfully progressed. One of the key reasons for this scenario is the continuing lack of a comprehensive disease model. Within the increasing complexity of modern research methods, there is a clear need for an overarching theoretical framework, in which findings are assimilated and predictions are generated. In this review and hypothesis article, we propose such a framework, one in which dysregulated energy expenditure is a primary, sufficient cause for BD. Our proposed model is centered on the disruption of the molecular and cellular network regulating energy production and expenditure, as well its potential secondary adaptations and compensatory mechanisms. We also focus on the putative longitudinal progression of this pathological process, considering its most likely periods for onset, such as critical periods that challenges energy homeostasis (e.g. neurodevelopment, social isolation), and the resulting short and long-term phenotypical manifestations. [ABSTRACT FROM AUTHOR]

Learning objectives: After participating in this activity, learners should be better able to: • Characterize cognitive dysfunction in patients with major depressive disorder. • Evaluate approaches to treating cognitive dysfunction in patients with major depressive disorder. Cognitive dysfunction is a core psychopathological domain in major depressive disorder (MDD) and is no longer considered to be a pseudo-specific phenomenon. Cognitive dysfunction in MDD is a principal determinant of patient-reported outcomes, which, hitherto, have been insufficiently targeted with existing multimodal treatments for MDD. The neural structures and substructures subserving cognitive function in MDD overlap with, yet are discrete from, those subserving emotion processing and affect regulation. Several modifiable factors influence the presence and extent of cognitive dysfunction in MDD, including clinical features (e.g., episode frequency and illness duration), comorbidity (e.g., obesity and diabetes), and iatrogenic artefact. Screening and measurement tools that comport with the clinical ecosystem are available to detect and measure cognitive function in MDD. Notwithstanding the availability of select antidepressants capable of exerting procognitive effects, most have not been sufficiently studied or rigorously evaluated. Promising pharmacological avenues, as well as psychosocial, behavioral, chronotherapeutic, and complementary alternative approaches, are currently being investigated. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: There is a need for a brief, reliable, valid, and sensitive assessment tool for screening cognitive deficits in patients with Major Depressive Disorders. This paper examines the psychometric characteristics of THINC‐it, a cognitive assessment tool composed of four objective measures of cognition and a self‐rated assessment, in subjects without mental disorders. Methods: N = 100 healthy controls with no current or past history of depression were tested on four sequential assessments to examine temporal stability, reliability, and convergent validity of the THINC‐it tests. We examined temporal reliability across 1 week and stability via three consecutive assessments. Consistency of assessment by the study rater (intrarater reliability) was calculated using the data from the second and third of these consecutive assessments. Results: Test–retest reliability correlations varied between Pearson's r = 0.75 and 0.8. Intrarater reliability between 0.7 and 0.93. Stability for the primary measure for each test yielded within‐subject standard deviation values between 5.9 and 11.23 for accuracy measures and 0.735 and 17.3 seconds for latency measures. Convergent validity for three tasks was in the acceptable range, but low for the Symbol Check task. Conclusions: Analysis shows high levels of reliability and stability. Levels of convergent validity were modest but acceptable in the case of all but one test. [ABSTRACT FROM AUTHOR]

The high and increasing prevalence of medical marijuana consumption in the general population invites the need for quality evidence regarding its safety and efficacy. Herein, we synthesize extant literature pertaining to the phytocannabinoid cannabidiol (CBD) and its brain effects. The principle phytocannabinoid Δ 9 -tetrahydrocannabinol (Δ 9 -THC) and CBD are the major pharmacologically active cannabinoids. The effect of CBD on brain systems as well as on phenomenological measures (e.g. cognitive function) are distinct and in many cases opposite to that of Δ 9 -THC. Cannabidiol is without euphoriant properties, and exerts antipsychotic, anxiolytic, anti-seizure, as well as anti-inflammatory properties. It is essential to parcellate phytocannabinoids into their constituent moieties as the most abundant cannabinoid have differential effects on physiologic systems in psychopathology measures. Disparate findings and reports related to effects of cannabis consumption reflect differential relative concentration of Δ 9 -THC and CBD. Existing literature, notwithstanding its deficiencies, provides empirical support for the hypothesis that CBD may exert beneficial effects on brain effector systems/substrates subserving domain-based phenomenology. Interventional studies with purified CBD are warranted with a call to target-engagement proof-of-principle studies using the research domain criteria (RDoC) framework. [ABSTRACT FROM AUTHOR]

Objectives To examine the role of pain on cognitive function in adults with major depressive disorder (MDD). Methods Adults (18–65) with a Diagnostic and Statistical Manual – Fifth Edition (DSM-5)-defined diagnosis of MDD experiencing a current major depressive episode (MDE) were enrolled ( n MDD = 100). All subjects with MDD were matched in age, sex, and years of education to healthy controls (HC) ( n HC = 100) for comparison. Cognitive function was assessed using the recently validated THINC-integrated tool (THINC-it), which comprises variants of the choice reaction time (i.e., THINC-it: Spotter ), One-Back (i.e., THINC-it: Symbol Check ), Digit Symbol Substitution Test (i.e., THINC-it: Codebreaker ), Trail Making Test – Part B (i.e., THINC-it: Trails ), as well as the Perceived Deficits Questionnaire for Depression – 5-item (i.e., THINC-it: PDQ-5-D ). A global index of objective cognitive function was computed using objective measures from the THINC-it, while self-rated cognitive deficits were measured using the PDQ-5-D. Pain was measured using a Visual Analogue Scale (VAS). Regression analyses evaluated the role of pain in predicting objective and subjective cognitive function. Results A significant between-group differences on the VAS was observed ( p < 0.001), with individuals with MDD reporting higher pain severity as evidenced by higher scores on the VAS than HC. Significant interaction effects were observed between self -rated cognitive deficits and pain ratings ( p < 0.001) on objective cognitive performance (after adjusting for MADRS total score), suggesting that pain moderates the association between self-rated and objective cognitive function. Conclusions Results indicated that pain is associated with increased self-rated and objective cognitive deficits in adults with MDD. Implications The study herein provides preliminary evidence demonstrating that adults with MDD reporting pain symptomatology and poorer subjective cognitive function is predictive of poorer objective cognitive performance. THINC-it is capable of detecting cognitive dysfunction amongst adults with MDD and pain. [ABSTRACT FROM AUTHOR]

Objectives: To explore the relationship between inflammation and neuronal metabolism in bipolar disorder (BD) by evaluating the neurochemical effects of the tumor necrosis factor-α (TNF-α) antagonist infliximab among individuals with bipolar depression METHODS: This is a post-hoc, exploratory analysis from a 12-week, randomized, double-blind, placebo-controlled trial with infliximab for adults with bipolar depression. We assessed the effects of infliximab on concentration of metabolites in the prefrontal cortex, using proton-magnetic resonance spectroscopy (1H-MRS), as well as its association with clinical outcomes (i.e. depressive symptom severity and cognitive function).Results: Eighteen participants in the placebo and 15 in the infliximab group were included in this analysis. In the pre-specified primary outcome, there were no significant effects of treatment on prefrontal concentrations of N-acetylaspartate (NAA; p = 0.712). In the secondary analyses, there was a significant treatment by time interaction for glutamate (Glx; p = 0.018), indicating that Glx levels decreased in infliximab-treated patients, relative to placebo. Treatment group significantly moderated the association between changes in Glx levels and changes in a neurocognitive test (i.e. Digit Symbol Substitution Test; p = 0.014), indicating that in infliximab-treated participants reductions in Glx were associated with cognitive improvement.Conclusions: Treatment with infliximab did not affect prefrontal NAA concentration in adults with BD. Exploratory analysis suggested a potential effect of treatment on the glutamate system, a finding that should be confirmed and validated by additional studies. [ABSTRACT FROM AUTHOR]

Highlights • MDD is a mental disorder characterized by aberrant emotion regulation. • Abnormal emotional control may result from dysfunctional cognitive processing. • The emotional response is comprised of affective and expressive components. • Lower limbic structures direct the expressive and affective components. • Higher cognitive structures allow for context-based emotional response modulation. Abstract Major depressive disorder (MDD) is a mental disorder characterized by aberrant emotion regulation. The capacity for emotion regulation stems from diverse neural circuits including higher level cognitive structures involved in processing contextual information, and lower level limbic structures involved in triggering emotional expression. Cognitive theories of depression posit that the MDD-specific abnormalities in emotional control derive itself from dysfunctional cognitive processes including biased attention, rumination, and altered information processing and memory. The main objectives of the current narrative review are to summarize the major neural systems involved in emotion regulation in humans, and to describe how these systems are dysregulated in MDD. The findings will be briefly discussed in the context of a conceptual framework of depression (i.e., Beck's cognitive model of depression), and neural targets of conventional treatments for depression will also be discussed. MDD exemplifies the critical importance of appropriate emotion regulation to human health and wellbeing, and demonstrates the personal and social impact of emotion dys regulation. [ABSTRACT FROM AUTHOR]

• Fatigue and cognitive impairment are amongst the most common and debilitating symptoms of post-COVID-19 syndrome. • Approximately 1 in 3 individuals experienced fatigue 12 or more weeks following COVID-19 diagnosis. • Approximately 1 in 5 individuals exhibited cognitive impairment 12 or more weeks following COVID-19 diagnosis. • There was an elevation in proinflammatory markers and functional impairment in a subset of post-COVID individuals. COVID-19 is associated with clinically significant symptoms despite resolution of the acute infection (i.e., post-COVID-19 syndrome). Fatigue and cognitive impairment are amongst the most common and debilitating symptoms of post-COVID-19 syndrome. To quantify the proportion of individuals experiencing fatigue and cognitive impairment 12 or more weeks following COVID-19 diagnosis, and to characterize the inflammatory correlates and functional consequences of post-COVID-19 syndrome. Systematic searches were conducted without language restrictions from database inception to June 8, 2021 on PubMed/MEDLINE, The Cochrane Library, PsycInfo, Embase, Web of Science, Google/Google Scholar, and select reference lists. Primary research articles which evaluated individuals at least 12 weeks after confirmed COVID-19 diagnosis and specifically reported on fatigue, cognitive impairment, inflammatory parameters, and/or functional outcomes were selected. Two reviewers independently extracted published summary data and assessed methodological quality and risk of bias. A meta-analysis of proportions was conducted to pool Freeman-Tukey double arcsine transformed proportions using the random-effects restricted maximum-likelihood model. The co-primary outcomes were the proportions of individuals reporting fatigue and cognitive impairment, respectively, 12 or more weeks following COVID-19 infection. The secondary outcomes were inflammatory correlates and functional consequences associated with post-COVID-19 syndrome. The literature search yielded 10,979 studies, and 81 studies were selected for inclusion. The fatigue meta-analysis comprised 68 studies, the cognitive impairment meta-analysis comprised 43 studies, and 48 studies were included in the narrative synthesis. Meta-analysis revealed that the proportion of individuals experiencing fatigue 12 or more weeks following COVID-19 diagnosis was 0.32 (95% CI, 0.27, 0.37; p < 0.001; n = 25,268; I2 = 99.1%). The proportion of individuals exhibiting cognitive impairment was 0.22 (95% CI, 0.17, 0.28; p < 0.001; n = 13,232; I2 = 98.0). Moreover, narrative synthesis revealed elevations in proinflammatory markers and considerable functional impairment in a subset of individuals. A significant proportion of individuals experience persistent fatigue and/or cognitive impairment following resolution of acute COVID-19. The frequency and debilitating nature of the foregoing symptoms provides the impetus to characterize the underlying neurobiological substrates and how to best treat these phenomena. PROSPERO (CRD42021256965). [ABSTRACT FROM AUTHOR]

Background: To assess the effect of insulin resistance (IR) on treatment response to the antidepressant, vortioxetine, in patients with Major Depressive Disorder (MDD).Methods: This is a secondary analysis of an 8-week, open-label clinical trial. Ninety-five adults in a primary care setting experiencing a major depressive episode were included. Response to vortioxetine was measured using the THINC-integrated tool, Montgomery Åsberg Depression Rating Scale (MADRS), the Snaith-Hamilton Pleasure Scale (SHAPS), the Perceived Deficits Questionnaire (PDQ-5), and the Sheehan Disability Scale (SDS). Generalized estimating equation models were utilized for data analysis.Results: When adjusted for age, gender, dose, and BMI, there was a significant baseline IR by time interaction for SHAPS (p = 0.022), PDQ-5 (p = 0.037), and SDS (p = 0.013). Higher baseline IR predicted decreased early improvements in anhedonia. It also predicted poorer subjective assessments of cognition and increased functional impairment at the endpoint of treatment. For functional capacity (i.e. SDS) other covariates including severity of symptoms, illness course, other metabolic factors (e.g. cholesterol), and physical activity were included with no changes to the moderating effect of baseline IR.Limitations: This was a post-hoc analysis of a primarily non-diabetic sample. Also, only one agent was assessed.Conclusions: IR was a predictor of response to vortioxetine. This persisted after controlling for other factors including, but not limited to, BMI. These findings strengthen the link between depression and IR and may point to another novel metabolic predictor of response. These findings should be replicated using other antidepressants. [ABSTRACT FROM AUTHOR]

Accumulating evidence suggests that disrupted insulin signaling is involved in bipolar disorder (BD) pathogenesis. Herein, we aimed to directly explore the potential role of neuronal insulin signaling using an innovative technique based on biomarkers derived from plasma extracellular vesicles enriched for neuronal origin (NEVs). We leveraged plasma samples from a randomized, double-blind, placebo-controlled, 12-week clinical trial evaluating infliximab as a treatment of bipolar depression. We isolated NEVs using immunoprecipitation against neuronal marker L1CAM from samples collected at baseline and weeks 2, 6 and 12 (endpoint) and measured NEV biomarkers using immunoassays. We assessed neuronal insulin signaling at its first node (IRS-1) and along the canonical (Akt, GSK-3β, p70S6K) and alternative (ERK1/2, JNK and p38-MAPK) pathways. A subset of participants (n = 27) also underwent whole-brain magnetic resonance imaging (MRI) at baseline and endpoint. Pre-treatment, NEV biomarkers of insulin signaling were independently associated with cognitive function and MRI measures (i.e. hippocampal and ventromedial prefrontal cortex [vmPFC] volumes). In fact, the association between IRS-1 phosphorylation at serine site 312 (pS312-IRS-1), an indicator of insulin resistance, and cognitive dysfunction was mediated by vmPFC volume. In the longitudinal analysis, patients treated with infliximab, a tumor necrosis factor-alpha antagonist with known insulin sensitizing properties, compared to those treated with placebo, had augmented phosphorylation of proteins from the alternative pathway. Infliximab responders had significant increases in phosphorylated JNK levels, relative to infliximab non-responders and placebo responders. In addition, treatment with infliximab resulted in increase in MRI measures of brain volume; treatment-related changes in the dorsolateral prefrontal cortex volume were mediated by changes in biomarkers from the insulin alternative pathway. In conclusion, our findings support the idea that brain insulin signaling is a target for further mechanistic and therapeutic investigations. [ABSTRACT FROM AUTHOR]

• Intravenous administration of ketamine is not associated with anti-cognitive effects. • IV ketamine in patients with TRD may have pro-cognitive effects in brain areas associated with visual learning and working memory. • Future studies should focus on cognition as a domain of depressive psychopathology. • Anxious and non-anxious TRD patients may vary in their response to intravenous ketamine treatment. Replicated evidence has documented cognitive deficits in populations with treatment-resistant depression (TRD). Approximately 40 % of patients with MDD present with impairment of one or more cognitive domains. As such, there is an unmet need to discover treatments that have pro-cognitive effects in TRD patients. Ketamine has demonstrated efficacy as a rapid-onset intervention for the treatment of depression. The objective of the current review was to assess the effects of ketamine on cognition in TRD patients. We systematically searched PubMed, Google Scholar and PsycINFO between database inception to March 24th, 2020. We identified five studies that evaluated cognition in TRD populations following ketamine treatment. All studies included a 0.5 mg/kg subanesthetic intravenous (IV) administration of ketamine. One study found significant improvements in complex (p =.008) and simple (p =.027) working memory and one study found improvements in visual learning memory following IV ketamine infusions (p =.014). Improvements in speed of processing and verbal learning memory were observed in anxious TRD participants only. Importantly, a subanesthetic dose of IV ketamine does not worsen cognitive function. [ABSTRACT FROM AUTHOR]

Abstract Type 2 Diabetes Mellitus (T2DM) and Major Depressive Disorder (MDD) are leading causes of disability worldwide. Indeed, both are costly and burdensome diseases at both individual and socio-economic levels. Notably, there are similar pathophysiological elements, which might explain the overlap in phenotypic symptoms and the high rate of comorbidity. Brain insulin resistance is a shared metabolic abnormality amongst many individuals with T2DM and MDD. Patients with either or both diseases often exhibit disturbances in cognition and mood, as well as the presence of anhedonia-like symptoms. However, individuals with T2DM with high glycemic control have reduced cognitive and depressive symptom burden. Based on this evidence, it is possible that repurposing therapies approved for treating insulin resistance may be useful in treating cognitive and anhedonia symptoms in depression. The objective of this review is to discuss the relationship between brain insulin resistance and depression, as well as possible disease modifying therapeutic agents targeting insulin signalling. [ABSTRACT FROM AUTHOR]

Background: Psychosocial impairment represents an important treatment target in major depressive disorder (MDD). The majority of patients with MDD do not regain premorbid levels of psychosocial functioning despite the resolution of core depressive symptoms. This study aimed to investigate the respective effects of cognitive function and depression severity on impaired psychosocial function in MDD.Methods: Adults aged 18-65 with moderate-to-severe MDD (n = 100) and age-, sex-, and education-matched healthy controls participated in a cross-sectional study validating the THINC-integrated tool (THINC-it), a cognitive screening tool comprised of objective and subjective measures of cognitive function. Depression severity was assessed using the Montgomery-Åsberg Depression Rating Scale and psychosocial function was assessed using the Sheehan Disability Scale (SDS).Results: Subjects with MDD reported greater impairment in psychosocial function than healthy controls, with significant differences in SDS total and domain scores (ps < .01) after controlling for age, sex, and education. Generalized linear models indicated that subjective cognitive function was most strongly associated with SDS total score (RR = .14, p = .01) and SDS domains of work/school (RR = .15, p = .03), family and home responsibilities (RR = .15, p = .02), and economic days lost (RR = .18, p =.03). Depression severity was most strongly associated with SDS social life (RR = .08, p < .01) and economic days underproductive (RR = .07, p < .01). Objective cognitive function was not significantly associated with any SDS outcomes.Limitations: The cross-sectional, observational study design limits temporal inferences. The self-report nature of measures included may have influenced associations observed. Potential medication effects are not noted.Conclusions: Cognitive deficits, as measured by the THINC-it, are associated with significant psychosocial impairment in MDD. These results provide empirical support for the assessment of both subjective and objective measures of cognition, as they are not associated with each other and have differential effects on functional trajectory. [ABSTRACT FROM AUTHOR]

Background: Bipolar disorder (BD) has been associated with cognitive impairment during depressed, manic and euthymic periods. Inflammation has been shown to be involved in the pathophysiology of BD and cognitive impairment.Methods: For this systematic review, the MEDLINE/PubMed, Embase, Google Scholar and ClinicalTrials.gov databases were searched for relevant articles assessing the association between cognitive function and inflammatory markers in BD subjects. A discussion of potential mechanisms and therapeutic implications is also included to provide further context to the subject matter.Results: Eight studies, including a total of 555 BD subjects, assessing the association between cognitive function and inflammatory markers were identified. Cognitive dysfunction was associated with elevated levels of pro-inflammatory markers YKL40, IL-6, sCD40L, IL-1Ra, hsCRP and TNF-α. Mechanistically, elevation in inflammatory cytokines alters monoamine levels leading to cognitive and affective dysfunction. Neuro-inflammation, manifesting as microglial activation, leads to increased oxidative stress, pathologic synaptic pruning and impaired neuroplasticity in key brain regions sub-serving mood and cognition. Immune dysfunction also activates the hypothalamic-pituitary-adrenal (HPA) axis leading to hypercortisolemia and metabolic dysfunction, further promoting neuronal dysfunction. Anti-inflammatory agents are therefore currently being investigated in the treatment of BD and appear to exert an antidepressant effect; however, cognitive outcomes have yet to be reported.Conclusion: Several studies suggest that immune dysfunction is associated with cognitive impairment in BD. Several neurobiological pathways have been identified whereby immune dysfunction may promote cognitive impairment in BD. Future investigations of anti-inflammatory agents targeting cognitive function as a treatment outcome are merited. [ABSTRACT FROM AUTHOR]

• Ketamine may improve cognition in adults with treatment-resistant depression. • Observed improvement in subjective and objective cognition measures. • Some improvements mediated by reductions in depressive symptoms. Ketamine may exert pro-cognitive effects on select measures of cognition in adults with mood disorders. We evaluated the effectiveness of intravenous (IV) ketamine on cognition in 68 adult outpatients with treatment-resistant depression (TRD) at the Canadian Rapid Treatment Center of Excellence between July 3, 2018 and April 16, 2020 (NCT04209296). Eligibility criteria for the present retrospective study included: primary diagnosis of major depressive or bipolar disorder; currently depressed; and insufficient response to two or more prior treatments. Participants received four infusions of ketamine hydrochloride (0.5-0.75 mg/kg) over 1-2 weeks. We assessed objective and subjective measures of cognition before and after two infusions, i.e., Digit Symbol Substitution Test (DSST), Trail Making Test-B (TMT-B), Patient Deficits Questionnaire, 5-item (PDQ-5-D). Ketamine significantly improved DSST (effect size [ES]=0.60), TMT-B (ES=0.84), as well as PDQ-5-D scores (ES=0.63), indicative of a moderate-to-large effect size. Improvements in DSST and PDQ-5-D with ketamine were mediated by reductions in depressive symptoms, whereas improvements in TMT-B were independent of changes in depressive symptoms. Our results support the independent, rapid-onset, pro-cognitive effects with IV ketamine in adults with TRD. Larger, randomized, controlled trials with ketamine wherein cognition is the primary outcome measure in mood and non-mood disorder samples are warranted. [ABSTRACT FROM AUTHOR]

Numerous pharmacological treatments for mood disorders are currently available; however, rates of treatment resistance, relapse and recurrence remain high. Therefore, novel treatments acting outside of the conventionally targeted monoamine system are urgently needed to improve patient outcomes. Emerging and converging evidence suggests that immune dysfunction, oxidative stress, impaired cerebral blood flow (CBF) and decreased neurotrophic factors all contribute to mood disorder pathophysiology and are therefore treatment targets of interest. Pentoxifylline (PTX) is a phosphodiesterase inhibitor with potent anti-inflammatory and antioxidant effects, with additional pleiotropic effects that lead to improved CBF and increases in brain derived neurotrophic factor (BDNF) levels. The direct effect of non-specific phosphodiesterase inhibition may also improve alertness and cognitive function through enhancing second messenger systems. Replicated preclinical studies have demonstrated antidepressant-like effects in animal models. Small preliminary clinical trials have demonstrated promising results for antidepressant and procognitive effects, however, have yet to be replicated in larger mood disorder samples. Only one randomized clinical trial (RCT) specifically assessed the effects of adjunctive PTX in major depressive disorder (MDD), showing clinically and statistically significant antidepressant effects compared to placebo. No studies have assessed PTX in bipolar disorder (BD), where inflammation and altered CBF have also been strongly implicated. Taken together, PTX presents as a promising pleiotropic agent with several potential novel mechanisms of action meriting further evaluation in clinical trials to evaluate target engagement, antidepressant, procognitive and mood stabilizing effects. • Immune dysfunction, oxidative stress and impaired cerebral blood flow are observed in mood disorders • Pentoxifylline (PTX) is a phosphodiesterase inhibitor with anti-inflammatory, antioxidant, and neurotrophic effects • PTX may improve cerebral blood flow • Preclinical and preliminary clinical data suggests that PTX may have antidepressant properties [ABSTRACT FROM AUTHOR]

• Loneliness has been associated with adverse health outcomes, but few studies have evaluated its comparative effects on distinct health outcomes. • A scoping review reveals medium to large effects of loneliness on all health outcomes, with the largest effects on mental health outcomes and overall well-being. • Healthcare providers should be adequately trained to perceive and respond to loneliness due to its strong associations with adverse health outcomes. The primary objective was to evaluate the comparative effects of loneliness on multiple distinct health outcomes. The literature was qualitatively reviewed to identify loneliness risk factors, explore mechanisms, and discuss potential evidence-based interventions for targeting loneliness. 114 identified studies were systematically reviewed and analyzed to examine for associations between loneliness (as measured by the UCLA Loneliness or de Jong Gierveld Loneliness Scales) and one or more health outcome(s). Health outcomes were broadly defined to include measures of mental health (i.e., depression, anxiety, suicidality, general mental health), general health (i.e., overall self-rated health), well-being (i.e., quality of life, life satisfaction), physical health (i.e., functional disability), sleep, and cognition. Loneliness had medium to large effects on all health outcomes, with the largest effects on mental health and overall well-being; however, this result may have been confounded by the breadth of studies exploring the association between loneliness and mental health, as opposed to other health outcomes. A significant effect of gender on the association between loneliness and cognition (i.e., more pronounced in studies with a greater proportion of males) was also observed. The adequate training of health care providers to perceive and respond to loneliness among patients should be prioritized. [ABSTRACT FROM AUTHOR]