Prescribed psychostimulants and other pro-cognitive medications in bipolar disorder: A systematic review and meta-analysis of recurrence of manic symptoms.

OBJECTIVES: Clinicians are often hesitant to prescribe psychostimulants in bipolar disorder (BD) due to concerns of inducing (hypo)mania, despite limited published evidence on associations between prescribed psychostimulant use and recurrence of mood episodes in BD. The current systematic review and meta-analysis evaluated the emergence of (hypo)manic symptoms in patients with BD receiving prescribed psychostimulants or other pro-cognitive medications in euthymic or depressive states. METHODS: A systematic search was performed of MEDLINE, Embase, and PsychINFO from inception to April 5, 2023 and search of Clinicaltrials.gov and Clinicaltrialsregister.eu for unpublished data. References of included studies were hand-searched. Randomized trials and prospective longitudinal studies that evaluated psychostimulants and non-stimulant medications recommended for the treatment of ADHD by the Canadian ADHD practice guidelines were included. The review was reported in line with PRISMA guidelines and was preregistered on PROSPERO (CRD42022358588). RESULTS: After screening 414 unique records, we included 27 studies, of which five reported data that was quantitatively synthesized (n = 1653). The use of psychostimulants in BD was not associated with increased scores on the Young Mania Rating Scale in patients who were in a euthymic or depressed state (SMD IV -0.17; 95% CI, -0.40 to 0.06) compared to placebo. There was a high degree of study-level heterogeneity (I2 = 80%). A qualitative synthesis of studies revealed a limited risk of medication-induced manic symptoms. CONCLUSIONS: Our review provides preliminary evidence to suggest psychostimulants and non-stimulant ADHD medications have a limited risk of precipitating (hypo)mania symptoms. More extensive studies evaluating the safety and efficacy of these medications are warranted.

A cross-sectional study of cognitive performance in bipolar disorder across the lifespan: the cog-BD project.

BACKGROUND: Neuroprogressive models of the trajectory of cognitive dysfunction in patients with bipolar disorder (BD) have been proposed. However, few studies have explored the relationships among clinical characteristics of BD, cognitive dysfunction, and aging. METHODS: We conducted a cross-sectional analysis in euthymic participants with the MATRICS Cognitive Consensus Battery, the Trail Making Test B, the Stroop Test, and the Wechsler Test of Adult Reading. Age- and gender-equated control participants without a mental disorder ['Healthy Controls' - HC)] were assessed similarly. We compared cognitive performance both globally and in seven domains in four groups: younger BD (age ⩽49 years; n = 70), older BD (age ⩾50 years; n = 48), younger HC (n = 153), and older HC (n = 44). We also compared the BD and HC groups using age as a continuous measure. We controlled for relevant covariates and applied a Bonferroni correction. RESULTS: Our results support both an early impairment ('early hit') model and an accelerated aging model: impairment in attention/vigilance, processing speed, and executive function/working memory were congruent with the accelerated aging hypothesis whereas impairment in verbal memory was congruent with an early impairment model. BD and HC participants exhibited similar age-related decline in reasoning/problem solving and visuospatial memory. There were no age- or diagnosis-related differences in social cognition. CONCLUSION: Our findings support that different cognitive domains are affected differently by BD and aging. Longitudinal studies are needed to explore trajectories of cognitive performance in BD across the lifespan.

Associations between peripheral inflammation and clinical phenotypes of bipolar depression in a lower-middle income country.

OBJECTIVE: There has been increased interest in repurposing anti-inflammatories for the treatment of bipolar depression. Evidence from high-income countries suggests that these agents may work best for specific depressive symptoms in a subset of patients with biochemical evidence of inflammation but data from lower-middle income countries (LMICs) is scarce. This secondary analysis explored the relationship between pretreatment inflammatory markers and specific depressive symptoms, clinical measures, and demographic variables in participants with bipolar depression in Pakistan. METHODS: The current study is a cross-sectional secondary analysis of a randomized controlled trial of two anti-inflammatory medications (minocycline and celecoxib) for bipolar depression (n = 266). A series of logistic and linear regression models were completed to assess the relationship between C-reactive protein (CRP) (CRP > or < 3 mg/L and log10CRP) and clinical and demographic features of interest and symptoms of depression. Baseline clinical trial data was used to extract clinical and demographic features and symptoms of depression were assessed using the 24-item Hamilton Depression Rating Scale. RESULTS: The prevalence of low-grade inflammation (CRP > 3 mg/L) in the sample was 70.9%. After adjusting for baseline body mass index, socioeconomic status, age, gender, symptoms related to anhedonia, fatigue, and motor retardation were most associated with low-grade inflammation. CONCLUSIONS: Bipolar disorder (BD) patients from LMICs may experience higher rates of peripheral inflammation than have been reported in Western populations with BD. Future trials of repurposed anti-inflammatory agents that enrich for participants with these symptom profiles may inform the development of personalized treatment for bipolar depression in LMICs.

Relative effectiveness of augmentation treatments for treatment-resistant depression: a systematic review and network meta-analysis.

Most interventions for treatment-resistant depression (TRD) are added as augmenters. We aimed to determine the relative effectiveness of augmentation treatments for TRD. This systematic review and network meta-analysis (NMA) sought all randomized trials of pharmacological and psychological augmentation interventions for adults meeting the most common clinical criteria for TRD. The NMA compared the intervention effectiveness of depressive symptoms for TRD augmentation. Of 36 included trials, 27 were suitable for inclusion in NMA, and no psychological trials could be included in the absence of a common comparator. Antipsychotics (13 trials), mood stabilizers (three trials), NMDA-targeting medications (five trials), and other mechanisms (3 trials) were compared against placebo. NMDA treatments were markedly superior to placebo (ES = 0.91, 95% CI 0.67 to 1.16) and head-to-head NMA suggested that NMDA therapies had the highest chance of being an effective treatment option compared to other pharmacological classes. This study provides the most comprehensive evidence of augmenters' effectiveness for TRD, and our GRADE recommendations can be used to guide guidelines to optimize treatment choices. Although conclusions are limited by paucity of, and heterogeneity between, trials as well as inconsistent reports of treatment safety. This work supports the use of NMDA-targeting medications such as ketamine.

A systematic review of structural and functional magnetic resonance imaging studies on the neurobiology of depressive symptoms in schizophrenia spectrum disorders.

Depressive symptoms in Schizophrenia Spectrum Disorders (SSDs) negatively impact suicidality, prognosis, and quality of life. Despite this, efficacious treatments are limited, largely because the neural mechanisms underlying depressive symptoms in SSDs remain poorly understood. We conducted a systematic review to provide an overview of studies that investigated the neural correlates of depressive symptoms in SSDs using neuroimaging techniques. We searched MEDLINE, PsycINFO, EMBASE, Web of Science, and Cochrane Library databases from inception through June 19, 2023. Specifically, we focused on structural and functional magnetic resonance imaging (MRI), encompassing: (1) T1-weighted imaging measuring brain morphology; (2) diffusion-weighted imaging assessing white matter integrity; or (3) T2*-weighted imaging measures of brain function. Our search yielded 33 articles; 14 structural MRI studies, 18 functional (f)MRI studies, and 1 multimodal fMRI/MRI study. Reviewed studies indicate potential commonalities in the neurobiology of depressive symptoms between SSDs and major depressive disorders, particularly in subcortical and frontal brain regions, though confidence in this interpretation is limited. The review underscores a notable knowledge gap in our understanding of the neurobiology of depression in SSDs, marked by inconsistent approaches and few studies examining imaging metrics of depressive symptoms. Inconsistencies across studies' findings emphasize the necessity for more direct and comprehensive research focusing on the neurobiology of depression in SSDs. Future studies should go beyond "total score" depression metrics and adopt more nuanced assessment approaches considering distinct subdomains. This could reveal unique neurobiological profiles and inform investigations of targeted treatments for depression in SSDs.

Boxing as an Intervention in Mental Health: A Scoping Review.

Introduction: Physical activity has been shown to have a multitude of mental health benefits. However, there is limited evidence on the specific mental health benefits of boxing. We conducted a scoping review of academic and grey literature to map research of boxing exercises as an intervention in mental health and to identify gaps in knowledge. Methods: The authors utilized the PRISMA-ScR methodological approach and guidelines from the Joanna Briggs Institute and a structured search was completed from inception until August 08, 2022. Results: We identified 16 documents that used non-contact boxing as an exercise intervention that improved various mental health difficulties. Non-contact boxing exercises, usually in a high-intensity-interval training group setting, provided significant reduction in symptoms of anxiety, depression, PTSD and negative symptoms of schizophrenia. Non-contact boxing provided a cathartic release of anger and stress, with evidence of improved mood, self-esteem, confidence, concentration, metabolic burden, strength and coordination. Conclusions: Preliminary evidence indicates that non-contact boxing exercises are a promising intervention to improve mental health burden. Further well designed randomized controlled trials using group, non-contact boxing exercises as an intervention for common mental disorders are warranted to confirm its benefits for mental health.

Protocol for a systematic review and meta-analysis of coordinate-based network mapping of brain structure in bipolar disorder across the lifespan.

BACKGROUND: Studies about brain structure in bipolar disorder have reported conflicting findings. These findings may be explained by the high degree of heterogeneity within bipolar disorder, especially if structural differences are mapped to single brain regions rather than networks. AIMS: We aim to complete a systematic review and meta-analysis to identify brain networks underlying structural abnormalities observed on T1-weighted magnetic resonance imaging scans in bipolar disorder across the lifespan. We also aim to explore how these brain networks are affected by sociodemographic and clinical heterogeneity in bipolar disorder. METHOD: We will include case-control studies that focus on whole-brain analyses of structural differences between participants of any age with a standardised diagnosis of bipolar disorder and controls. The electronic databases Medline, PsycINFO and Web of Science will be searched. We will complete an activation likelihood estimation analysis and a novel coordinate-based network mapping approach to identify specific brain regions and brain circuits affected in bipolar disorder or relevant subgroups. Meta-regressions will examine the effect of sociodemographic and clinical variables on identified brain circuits. CONCLUSIONS: Findings from this systematic review and meta-analysis will enhance understanding of the pathophysiology of bipolar disorder. The results will identify brain circuitry implicated in bipolar disorder, and how they may relate to relevant sociodemographic and clinical variables across the lifespan.

Beyond Psilocybin: Reviewing the Therapeutic Potential of Other Serotonergic Psychedelics in Mental and Substance Use Disorders.

There has been a resurgence of interest in the use of psychedelic therapies for several mental and substance use disorders. Psilocybin, a "classic" serotonergic psychedelic, has emerged as one of the primary compounds of interest in clinical research. While research on psilocybin's potential mental health benefits has grown, data on the safety and efficacy of other serotonergic psychedelics remain limited. A comprehensive scoping review on the use of mescaline, ibogaine, ayahuasca, N,N-dimethyltryptamine (DMT), and lysergic acid diethylamide (LSD) in the treatment of mental and substance disorders was conducted. Independent reviewers screened titles, abstracts, and full texts and conducted data extraction. Seventy-seven studies met the inclusion criteria. There were 43 studies of LSD, 24 studies of ayahuasca, 5 studies of DMT, 5 studies of ibogaine, and 5 studies of mescaline. Commonly reported benefits included improved mood and anxiety symptoms, improved insight, reduced substance use, improved relationships, and decreased vegetative symptoms. Commonly reported adverse effects were psychological, neurological, physical, and gastrointestinal in nature. Serious adverse events (homicide and suicide) were reported in published studies of LSD. In conclusion, there is only low-level evidence to support the safety and efficacy of non-psilocybin serotonergic psychedelics in individuals with mental and substance use disorders.

Treatment outcomes in major depressive disorder in patients with comorbid alcohol use disorder: A STAR*D analysis.

INTRODUCTION: Guidance on Major Depressive Disorder (MDD) treatment in those with comorbid Alcohol Use Disorder (AUD) is limited. We performed a secondary analysis on the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, examining the association between comorbid AUD and depression outcomes. METHODS: STAR*D was a real-world effectiveness trial starting with citalopram in level 1. Non-responding participants progressed through 3 other sequential treatment levels with different switch or augmentation options. Antidepressant outcomes were compared between MDD (n = 2826) and comorbid MDD and AUD (n = 864). Logistic regressions were performed to evaluate remission and response predictors in the total STAR*D sample and the AUD-comorbidity interaction. RESULTS: Chi-squared tests showed no significant difference in response or remission rates from depression between groups across treatment levels. Higher Hamilton Rating Scale for Depression (HRSD) score was associated with overall lower odds of remission in treatment level 1 (OR = 0.93, p < 0.001) and 2 (OR = 0.95, p < 0.001), with no significant interaction with comorbid AUD. Higher baseline suicidality had overall lower odds of remission in level 1 (OR = 0.82, p < 0.001) and 2 (OR = 0.1, p < 0.001), but with comorbid AUD compared to no AUD, suicidality increased odds of level 1 remission (OR = 1.30, p = 0.012). In comorbid AUD in level 2, venlafaxine was associated with lower odds of remission (OR = 0.13, p = 0.013) and response (OR = 0.12, p = 0.006); bupropion with lower odds of response (OR = 0.22, p = 0.024). LIMITATIONS: Open label study design and lack of alcohol use data. CONCLUSIONS: Comorbid AUD may interact with predictors of antidepressant response in MDD and using venlafaxine or bupropion may be less effective. Addressing this comorbidity requires unique assessment and treatment approaches.

A systematic review on the effectiveness of dialectical behavior therapy for improving mood symptoms in bipolar disorders.

BACKGROUND: Evidence-based psychotherapies available to treat patients with bipolar disorders (BD) are limited. Dialectical behavior therapy (DBT) may target several common symptoms of BD. We conducted a systematic review on the efficacy of DBT for mood symptoms in patients with BD. The systematic search used key words related to DBT and BD in Medline, Embase, PsycInfo, CINAHL, and Cochrane Library databases from 1980 to April 1st, 2022. We included studies that enrolled patients with a BD I or II diagnosis (DSM or ICD), age 12 and older who received a DBT-based intervention. Studies reviewed were clinical trials including observational studies that reported at least one outcome related to BD mood symptoms or severity. We did not exclude based upon psychiatric or physical co-morbidity. RESULTS: We screened 848 abstracts and reviewed 28 full texts; 10 publications with 11 studies met our pre-determined eligibility criteria. All but one were feasibility pilot studies and most included participants in all mood states except for mania. The studies provided preliminary evidence suggesting these interventions may be effective for improving several core symptoms of BD. Overall, all the studies consistently supported that DBT-based interventions are feasible and acceptable for patients with BD. CONCLUSION: DBT may be an effective treatment for BD; however, the confidence in this conclusion is limited by the small sample sizes, heterogeneity, and high risk of bias in all published trials. Larger well-designed RCTs are now required to establish the effectiveness of DBT in BD.

Psilocybin for treatment-resistant depression without psychedelic effects: study protocol for a 4-week, double-blind, proof-of-concept randomised controlled trial.

BACKGROUND: Randomised controlled trials (RCTs) of psilocybin have reported large antidepressant effects in adults with major depressive disorder and treatment-resistant depression (TRD). Given psilocybin's psychedelic effects, all published studies have included psychological support. These effects depend on serotonin 2A (5-HT2A) receptor activation, which can be blocked by 5-HT2A receptor antagonists like ketanserin or risperidone. In an animal model of depression, ketanserin followed by psilocybin had similar symptomatic effects as psilocybin alone. AIMS: To conduct a proof-of-concept RCT to (a) establish feasibility and tolerability of combining psilocybin and risperidone in adults with TRD, (b) show that this combination blocks the psychedelic effects of psilocybin and (c) provide pilot data on the antidepressant effect of this combination (compared with psilocybin alone). METHOD: In a 4-week, three-arm, 'double dummy' trial, 60 adults with TRD will be randomised to psilocybin 25 mg plus risperidone 1 mg, psilocybin 25 mg plus placebo, or placebo plus risperidone 1 mg. All participants will receive 12 h of manualised psychotherapy. Measures of feasibility will include recruitment and retention rates; tolerability and safety will be assessed by rates of drop-out attributed to adverse events and rates of serious adverse events. The 5-Dimensional Altered States of Consciousness Rating Scale will be a secondary outcome measure. RESULTS: This trial will advance the understanding of psilocybin's mechanism of antidepressant action. CONCLUSIONS: This line of research could increase acceptability and access to psilocybin as a novel treatment for TRD without the need for a psychedelic experience and continuous monitoring.

Astrocytes in the Neuropathology of Bipolar Disorder: Review of Current Evidence.

(1) Background: Approximately one-third of patients with bipolar disorder (BD) do not experience sustained remission with current treatments. Presently, astrocytes, i.e., glial cells that act as key regulators of neuroinflammation, have been a target for therapeutic development. Research regarding their role in the neuropathology of BD is limited. We conducted a scoping review on evidence linking astrocytes to the pathology of BD. (2) Methods: The search was conducted in MEDLINE for studies published from inception to August 2022. Studies of interest were data-extracted and reported based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols. (3) Results: Overall, 650 publications were identified, of which 122 full texts were evaluated and 12 included. Four were in vitro, seven were ex vivo, and one study was both in vitro and in vivo. In vitro investigations focused on plasma levels of neuroinflammatory biomarkers S100B and glial fibrillary acidic protein (GFAP). Ex vivo investigations were post-mortem brain studies assessing astrocytes in regions of interest (i.e., anterior cingulate cortex, dorsolateral prefrontal cortex) using phosphorylated GFAP and ASCT-1. The in vivo and in vitro study evaluated morphological and chemical variations of YKL-40 between cohorts. (4) Conclusions: Reports indicate an association between astrocyte dysfunction and BD although larger studies are required to validate this association.

Brief App-Based Cognitive Behavioral Therapy for Anxiety Symptoms in Psychiatric Inpatients: Feasibility Randomized Controlled Trial.

BACKGROUND: Psychiatric inpatients often have limited access to psychotherapeutic education or skills for managing anxiety, a common transdiagnostic concern in severe and acute mental illness. COVID-19-related restrictions further limited access to therapy groups on inpatient psychiatric units. App-based interventions may improve access, but evidence supporting the feasibility of their use, acceptability, and effectiveness in psychiatric inpatient settings is limited. MindShift CBT is a free app based on cognitive behavioral therapy principles with evidence for alleviating anxiety symptoms in the outpatient setting. OBJECTIVE: We aimed to recruit 24 participants from an acute general psychiatric inpatient ward to a 1-month randomized control study assessing the feasibility and acceptability of providing patients with severe and acute mental illness access to the MindShift CBT app for help with managing anxiety symptoms. METHODS: Recruitment, data collection, analysis, and interpretation were completed collaboratively by clinician and peer researchers. Inpatients were randomized to two conditions: treatment as usual (TAU) versus TAU plus use of the MindShift CBT app over 6 days. We collected demographic and quantitative data on acceptability and usability of the intervention. Symptoms of depression, anxiety, and psychological distress were measured in pre- and poststudy surveys for preliminary signals of efficacy. We conducted individual semistructured interviews with participants in the MindShift CBT app group at the end of their trial period, which were interpreted using a standardized protocol for thematic analysis. RESULTS: Over 4 weeks, 33 inpatients were referred to the study, 24 consented to participate, 20 were randomized, and 11 completed the study. Of the 9 randomized participants who did not complete the study, 7 were withdrawn because they were discharged or transferred prior to study completion, with a similar distribution among both conditions. Among the enrolled patients, 65% (13/20) were admitted for a psychotic disorder and no patient was admitted primarily for an anxiety disorder. The average length of stay was 20 days (SD 4.4; range 3-21) and 35% (7/20) of patients were involuntarily admitted to hospital. Small sample sizes limited accurate interpretation of the efficacy data. Themes emerging from qualitative interviews included acceptability and usability of the app, and patient agency associated with voluntary participation in research while admitted to hospital. CONCLUSIONS: Our study benefitted from collaboration between peer and clinician researchers. Due to rapid patient turnover in the acute inpatient setting, additional flexibility in recruitment and enrollment is needed to determine the efficacy of using app-based psychotherapy on an acute psychiatric ward. Despite the limited sample size, our study suggests that similar interventions may be feasible and acceptable for acutely unwell inpatients. Further study is needed to compare the efficacy of psychotherapeutic apps with existing standards of care in this setting. TRIAL REGISTRATION: ClinicalTrials.gov NCT04841603; https://clinicaltrials.gov/ct2/show/NCT04841603.

Frequency analysis of symptomatic worsening following ketamine infusions for treatment resistant depression in a real-world sample: Results from the canadian rapid treatment center of excellence.

Antidepressants are associated with symptomatic worsening in a subgroup of patients. Replicated evidence has demonstrated rapid and robust antidepressant effects with intravenous (IV) ketamine in treatment resistant depression (TRD); however, the risk of ketamine worsening depressive symptoms in a subgroup of patients remains unknown. Herein we report a retrospective analysis on the rates of symptomatic worsening during an acute course of IV ketamine in individuals with unipolar (n = 142) and bipolar (n = 22) TRD. Adults (N = 164; mean age = 45.97) with TRD underwent four sub-anesthetic infusions (0.5-0.75 mg/kg over 40 min) of IV ketamine over two weeks, and were assessed with the Quick Inventory for Depression Symptomatology-Self Report-16 (QIDS-SR16) at baseline and after each infusion. The primary outcome was the proportion of patients experiencing clinically significant worsening of depressive symptoms (≥20% increase on the QIDS-SR16) at each time point relative to baseline. Secondary analyses explored trends in the results. The frequency of clinically significant worsening fluctuated between 1.83% to 5.49%, with no identifiable trend across time. Zero individuals with bipolar TRD reported symptomatic worsening. Limitations include the single-centered, uncontrolled, retrospective nature of this study. Rates of symptomatic worsening associated with IV ketamine therapy for TRD appear to be very low and similar to conventional antidepressants.

Metabolic function in patients with bipolar depression receiving anti-inflammatory agents: Findings from the MINDCARE study, a multicentre, randomised controlled trial.

BACKGROUND: Metabolic dysfunction is prevalent in bipolar disorder (BD) and associated with illness severity and treatment outcomes. There is little research exploring this relationship in low and middle-income countries (LMICs) and little is known about the moderating effect of metabolic health on treatment response to anti-inflammatory drugs in BD. METHODS: MINDCARE, a randomized-controlled-trial conducted in Pakistan, investigated the efficacy of minocycline and celecoxib in 266 adults with bipolar depression. This secondary analysis evaluated the association between depression severity at baseline and treatment outcome with metabolic parameters including body mass index (BMI), waist circumference (WC), heart rate (HR), systolic blood pressure (s-BP), and diastolic blood pressure (d-BP). Depression severity was measured using the Hamilton Depression Rating Scale-17. The exploratory aim was to assess whether treatment impacted change in metabolic variables. Associations were evaluated using linear regression. RESULTS: Higher BMI (B=-0.38, 95%CI: -0.55 to -0.21) and WC (B=-0.68, 95%CI: -0.97 to -0.39) were associated with lower baseline depression severity in both the unadjusted and the adjusted models. Baseline metabolic parameters were not associated with treatment response to minocycline or celecoxib nor did treatment significantly impact metabolic variables. LIMITATIONS: Our sample represents patients in an RCT and may not be fully representative of the overall BD population in Pakistan. CONCLUSIONS: Our findings indicate a potential association of poor metabolic health and lower severity of bipolar depression but not treatment outcomes. Future work should evaluate potential relationships of metabolic parameters and BD in diverse populations to increase the transferability of this line of work.

The use of sequential pharmacotherapy for the treatment of acute major depression: a scoping review.

INTRODUCTION: Major Depressive Disorder (MDD) is a chronic, relapsing, and remitting disorder affecting over 250 million persons each year worldwide. More than 50% of the patients do not respond to their initial antidepressant treatment and may benefit from sequential pharmacotherapy for the acute treatment of their MDD. Although guidelines outline options for next-step treatments, there is a paucity of evidence to select specific second- or third-step treatments. AREAS COVERED: This scoping review synthesizes and discusses available evidence for sequential pharmacotherapy for MDD. MEDLINE was searched from inception to 7 July 2020; 4490 studies were identified. We selected meta-analyses and reports on clinical trials that were judged to inform the sequential selection of pharmacotherapy for MDD. EXPERT OPINION: Most relevant published trials are focused on, and support, the use of augmentation pharmacotherapy. There is also some support for other strategies such as combining or switching antidepressants. In the future, more studies need to directly compare these sequential options. To provide more personalized treatment within the framework of precision psychiatry, these studies should include an assessment of moderators and mediators ('mechanism') of antidepressant response.

Targeting Metabolic Dysfunction for the Treatment of Mood Disorders: Review of the Evidence.

Major depressive disorder (MDD) and bipolar disorder (BD) are often chronic with many patients not responding to available treatments. As these mood disorders are frequently associated with metabolic dysfunction, there has been increased interest in novel treatments that would target metabolic pathways. The objectives of this scoping review were to synthesize evidence on the impact on mood symptoms of lipid lowering agents and anti-diabetics drugs, while also reviewing current knowledge on the association between mood disorders and dyslipidemia or hyperglycemia. We propose that metabolic dysfunction is prevalent in both MDD and BD and it may contribute to the development of these disorders through a variety of pathophysiological processes including inflammation, brain structural changes, hormonal alterations, neurotransmitter disruptions, alteration on brain cholesterol, central insulin resistance, and changes in gut microbiota. Current evidence is conflicting on the use of statins, polyunsaturated fatty acids, thiazolidinediones, glucagon-like peptide agonists, metformin, or insulin for the treatment of MDD and BD. Given the paucity of high-quality randomized controlled trials, additional studies are needed before any of these medications can be repurposed in routine clinical practice. Future trials need to enrich patient recruitment, include evaluations of mechanism of action, and explore differential effects on specific symptom domains such as anhedonia, suicidality, and cognition.

Protocol for a systematic review and meta-analysis of the placebo response in treatment-resistant depression: comparison of multiple treatment modalities.

INTRODUCTION: The high placebo response in depression treatment trials is a major contributing factor for randomised control trial failure to establish efficacy of novel or repurposed treatments in treatment-resistant depression (TRD) and major depressive disorder in general. Though there have been a number of meta-analyses and primary research studies evaluating the placebo response in non-TRD, placebo response in TRD is poorly understood. It is important to understand the placebo response of TRD as treatments are only moderately effective and up to 1/3 of patients will experience TRD. METHODS AND ANALYSIS: We will conduct a search of electronic databases (MEDLINE and PsychINFO) from inception to 24th January 2020 including randomised, placebo-controlled trials of pharmacological, somatic and psychological interventions for adults with TRD. TRD will be defined as a failure to respond to at least two interventions of adequate dose or duration. We will also search reference lists from review articles. We will perform several meta-analyses to quantify the placebo response for each treatment modality. Regression analysis will explore potential contributing demographic and clinical variables to the placebo response. We will use Cochrane risk of bias tool. ETHICS AND DISSEMINATION: There is no research ethics board approval required. The dissemination plan is to publish results in a peer-reviewed academic journal. PROSPERO REGISTRATION NUMBER: 190 465.

Metabolic variables associated with response to cognitive behavioural therapy for depression in females: A Canadian biomarker integration network for depression (CAN-BIND) study.

INTRODUCTION: Cognitive behavioural therapy (CBT) is an established first-line treatment for depression; however, it remains unclear which factors predict a positive outcome with this approach. Prior work suggests that co-morbid obesity predicts a poorer response to antidepressant medication. The current study examined whether there is an association between weight parameters and improvement of depressive symptoms with CBT. METHODS: This was a secondary analysis of data from the "Clinical and Biological Markers of Response to Cognitive Behavioural Therapy for Depression - 6" (CANBIND-6; https://clinicaltrials.gov/ct2/show/NCT02883257) study. Adult participants (n = 41) with a diagnosis of Major Depressive Disorder (MDD) or Persistent Depressive Disorder (PDD) were recruited from an outpatient tertiary psychiatric centre in Canada. Participants completed 20 individual sessions of CBT over 16 weeks. The primary measure for treatment outcome was the Montgomery-Åsberg Depression Rating Scale (MADRS) total score at week 16. RESULTS: Thirty-seven participants completed assessments pre and post CBT. Baseline weight parameters were not correlated with treatment response to CBT in the entire group. There was a significant sex*waist circumference (WC) (B:-1.34; p = 0.004) and sex*body mass index (BMI) interaction (B:-2.03; p:0.009). In female participants, baseline waist circumference, but not BMI, significantly predicted week 16 MADRS after controlling for age and baseline MADRS (B:0.422 p:0.049). LIMITATIONS: The major limitation of our preliminary finding is the small sample size. CONCLUSION: Our preliminary findings suggest that higher waist circumference may be associated with a better treatment response to CBT for depression in females. This result could be of clinical relevance and warrants further investigation in larger and independent samples.

Magnitude of the Placebo Response Across Treatment Modalities Used for Treatment-Resistant Depression in Adults: A Systematic Review and Meta-analysis.

Importance: The placebo effect in depression clinical trials is a substantial factor associated with failure to establish efficacy of novel and repurposed treatments. However, the magnitude of the placebo effect and whether it differs across treatment modalities in treatment-resistant depression (TRD) is unclear. Objective: To examine the magnitude of the placebo effect in patients with TRD across different treatment modalities and its possible moderators. Data Sources: Searches were conducted on MEDLINE, Web of Science, and PsychInfo from inception to June 21, 2021. Study Selection: Randomized clinical trials (RCTs) were included if they recruited patients with TRD and randomized them to a placebo or sham arm and a pharmacotherapy, brain stimulation, or psychotherapy arm. Data Extraction and Synthesis: Independent reviewers used standard forms for data extraction and quality assessment. Random-effects analyses and standard pairwise meta-analyses were performed. Main Outcomes and Measures: The primary outcome was the Hedges g value for the reported depression scales. Secondary outcomes included moderators assessed via meta-regression and response and remission rates. Heterogeneity was assessed with the I2 test, and publication bias was evaluated using the Egger test and a funnel plot. Cochrane Risk of Bias Tool was used to estimate risks. Results: Fifty RCTs were included involving various types of placebo or sham interventions with a total of 3228 participants (mean [SD] age, 45.8 [6.0] years; 1769 [54.8%] female). The pooled placebo effect size for all modalities was large (g = 1.05; 95% CI, 0.91-1.1); the placebo effect size in RCTs of specific treatment modalities did not significantly differ. Similarly, response and remission rates associated with placebo were comparable across modalities. Heterogeneity was large. Three variables were associated with a larger placebo effect size: open-label prospective treatment before double-blind placebo randomization (ß = 0.35; 95% CI, 0.11 to 0.59; P = .004), later year of publication (ß = 0.03; 95% CI, 0.003 to 0.05; P = .03), and industry-sponsored trials (ß = 0.34; 95% CI, 0.09 to 0.58; P = .007). The number of failed interventions was associated with the probability a smaller placebo effect size (ß = -0.12; 95% CI, -0.23 to -0.01, P = .03). The Egger test result was not significant for small studies' effects. Conclusions and Relevance: This analysis may provide a benchmark for past and future clinical RCTs that recruit patients with TRD standardizing an expected placebo effect size.