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EClinicalMedicine Aug 2023Intranasal esketamine has received regulatory approvals for the treatment of depression. Recently a large trial of repeated dose racemic ketamine also demonstrated...
BACKGROUND
Intranasal esketamine has received regulatory approvals for the treatment of depression. Recently a large trial of repeated dose racemic ketamine also demonstrated efficacy in severe depression. However, uncertainties remain regarding comparative efficacy, dosage, and the time course of response.
METHODS
In this systematic review and meta-analysis, we searched Embase, Medline, Pubmed, PsycINFO, and CENTRAL up to April 13, 2023, for randomised controlled trials (RCTs) investigating ketamine for depression. Two investigators independently assessed study eligibility and risk of bias and extracted the data on depression severity scores, response and remission rates, and all-cause dropouts. Multivariable mixed-effects meta-regressions incorporated drug formulation (racemic (Rac) or esketamine (Esket)) and dose (Low or High) as covariates. Treatment effects were assessed: immediately following the first dose, during further repeated dosing, and follow-up after the final dose of a treatment course. This study is registered with PROSPERO (CRD42021221157).
FINDINGS
The systematic review identified 687 articles, of which 49 RCTs were eligible for analysis, comprising 3299 participants. Standardised mean differences (95% confidence intervals) immediately following the first/single treatment were moderate-high for all conditions (Rac-High: -0.73, -0.91 to -0.56; Esket-High: -0.48, -0.75 to -0.20; Rac-Low: -0.33, -0.54 to -0.12; Esket-Low: -0.55, -0.87 to -0.24). Ongoing effects during repeated dosing were significantly greater than the control for Rac-High (-0.61; -1.02 to -0.20) and Rac-Low (-0.55, -1.09 to -0.00), but not Esket-Low (-0.15, -0.49 to 0.19) or Esket-High (-0.22, -0.54 to 0.10). At follow-up effects remained significant for racemic ketamine (-0.65; -1.23 to -0.07) but not esketamine (-0.33; -0.96 to 0.31). All-cause dropout was similar between experiment and control conditions for both formulations combined (Odds Ratio = 1.18, 0.85-1.64). Overall heterogeneity varied from 5.7% to 87.6.
INTERPRETATION
Our findings suggested that effect sizes for depression severity, as well as response and remission rates, were numerically greater for racemic ketamine than esketamine. Higher doses were more effective than low doses. Differences were evident in initial effects, ongoing treatment, and lasting effects after the final dose.
FUNDING
None.
PubMed: 37593223
DOI: 10.1016/j.eclinm.2023.102127 -
Frontiers in Neuroscience 2023There are previous epidemiological studies reporting associations between antibiotic use and psychiatric symptoms. Antibiotic-induced gut dysbiosis and alteration of... (Review)
Review
There are previous epidemiological studies reporting associations between antibiotic use and psychiatric symptoms. Antibiotic-induced gut dysbiosis and alteration of microbiota-gut-brain axis communication has been proposed to play a role in this association. In this systematic review and meta-analysis, we reviewed published articles that have presented results on changes in cognition, emotion, and behavior in rodents (rats and mice) after antibiotic-induced gut dysbiosis. We searched three databases-PubMed, Web of Science, and SCOPUS to identify such articles using dedicated search strings and extracted data from 48 articles. Increase in anxiety and depression-like behavior was reported in 32.7 and 40.7 percent of the study-populations, respectively. Decrease in sociability, social novelty preference, recognition memory and spatial cognition was found in 18.1, 35.3, 26.1, and 62.5 percent of the study-populations, respectively. Only one bacterial taxon (increase in gut ) showed statistically significant association with behavioral changes (increase in anxiety). There were no consistent findings with statistical significance for the potential biomarkers [Brain-derived neurotrophic factor (BDNF) expression in the hippocampus, serum corticosterone and circulating IL-6 and IL-1β levels]. Results of the meta-analysis revealed a significant association between symptoms of negative valence system (including anxiety and depression) and cognitive system (decreased spatial cognition) with antibiotic intake ( < 0.05). However, between-study heterogeneity and publication bias were statistically significant ( < 0.05). Risk of bias was evaluated to be high in the majority of the studies. We identified and discussed several reasons that could contribute to the heterogeneity between the results of the studies examined. The results of the meta-analysis provide promising evidence that there is indeed an association between antibiotic-induced gut dysbiosis and psychopathologies. However, inconsistencies in the implemented methodologies make generalizing these results difficult. Gut microbiota depletion using antibiotics may be a useful strategy to evaluate if and how gut microbes influence cognition, emotion, and behavior, but the heterogeneity in methodologies used precludes any definitive interpretations for a translational impact on clinical practice.
PubMed: 37719161
DOI: 10.3389/fnins.2023.1237177 -
JAMA Network Open Oct 2023Reliable screening for major depressive disorder (MDD) relies on valid and accurate screening tools. (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Reliable screening for major depressive disorder (MDD) relies on valid and accurate screening tools.
OBJECTIVE
To examine the validity, accuracy, and reliability of the Spanish-language Patient Health Questionnaires 2 and 9 (PHQ-2 and PHQ-9) to screen for MDD.
DATA SOURCES
PubMed, Web of Science, Embase, and PsycINFO from data initiation through February 27, 2023.
STUDY SELECTION
English- and Spanish-language studies evaluating the validity of the Spanish-language PHQ-2 or PHQ-9 in screening adults for MDD compared with a standardized clinical interview (gold standard). Search terms included PHQ-2, PHQ-9, depression, and Spanish.
DATA EXTRACTION AND SYNTHESIS
Two reviewers performed abstract and full-text reviews, data extraction, and quality assessment. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Random-effects meta-analyses of sensitivity, specificity, and area under the curve (AUC) were performed. Internal consistency was evaluated using Cronbach α and McDonald ψ.
MAIN OUTCOMES AND MEASURES
Test accuracy and internal consistency. The PHQ-2 is composed of the first 2 questions of the PHQ-9 (targeting core depression symptoms of depressed mood and anhedonia; a score of 3 or higher (score range, 0-6) is generally considered a positive depression screen. If a patient screens positive with the PHQ-2, a follow-up assessment with the PHQ-9 and a clinical diagnostic evaluation are recommended. Once depression is diagnosed, a PHQ-9 score of 10 or higher (score range, 0-27) is often considered an acceptable threshold for treating depression.
RESULTS
Ten cross-sectional studies involving 5164 Spanish-speaking adults (mean age range, 34.1-71.8 years) were included; most studies (n = 8) were in primary care settings. One study evaluated the PHQ-2, 7 evaluated the PHQ-9, and 2 evaluated both the PHQ-2 and PHQ-9. For the PHQ-2, optimal cutoff scores ranged from greater than or equal to 1 to greater than or equal to 2, with an overall pooled sensitivity of 0.89 (95% CI, 0.81-0.95), overall pooled specificity of 0.89 (95% CI, 0.81-0.95), and overall pooled AUC of 0.87 (95% CI, 0.83-0.90); Cronbach α was 0.71 to 0.75, and McDonald ψ was 0.71. For the PHQ-9, optimal cutoff scores ranged from greater than or equal to 5 to greater than or equal to 12, with an overall pooled sensitivity of 0.86 (95% CI, 0.82-0.90), overall pooled specificity of 0.80 (95% CI, 0.75-0.85), and overall pooled AUC of 0.88 (95% CI, 0.87-0.90); Cronbach α was 0.78 to 0.90, and McDonald ψ was 0.79 to 0.90. Four studies were considered to have low risk of bias; 6 studies had indeterminate risk of bias due to a lack of blinding information.
CONCLUSIONS AND RELEVANCE
In this systematic review and meta-analysis, limited available evidence supported the use of the Spanish-language PHQ-2 and PHQ-9 in screening for MDD, but optimal cutoff scores varied greatly across studies, and few studies reported on blinding schemes. These results suggest that MDD should be considered in Spanish-speaking individuals with lower test scores. Given the widespread clinical use of the tools and the heterogeneity of existing evidence, further investigation is needed.
Topics: Adult; Humans; Middle Aged; Aged; Patient Health Questionnaire; Depressive Disorder, Major; Reproducibility of Results; Cross-Sectional Studies; Surveys and Questionnaires; Language
PubMed: 37847505
DOI: 10.1001/jamanetworkopen.2023.36529 -
CNS Neuroscience & Therapeutics Mar 2024Noninvasive brain stimulation (NIBS) techniques are a promising tool for treating the negative symptoms of schizophrenia. Growing evidence suggests that different... (Meta-Analysis)
Meta-Analysis
Is it more effective for anhedonia and avolition? A systematic review and meta-analysis of non-invasive brain stimulation interventions for negative symptoms in schizophrenia.
BACKGROUND
Noninvasive brain stimulation (NIBS) techniques are a promising tool for treating the negative symptoms of schizophrenia. Growing evidence suggests that different dimensions of negative symptoms have partly distinct underlying pathophysiological mechanisms. Previous randomized controlled trials (RCTs) have shown inconsistent impacts of NIBS across dimensions.
OBJECTIVE
This systematic review and meta-analysis evaluated the effects of NIBS on general negative symptoms, and on specific domains, including blunted affect, alogia, asociality, anhedonia, and avolition.
DATA SOURCES
PubMed, Web of Science, Embase, Cochrane CENTRAL, PsycINFO, OpenGrey, and Clinicaltrials.gov from the first date available to October, 2023.
RESULTS
Among 1049 studies, we identified eight high-quality RCTs. NIBS significantly affects general negative symptoms (SMD = -0.54, 95% CI [-0.88, -0.21]) and all five domains (SMD = -0.32 to -0.63). Among dimensions, better effects have been shown for improvement of avolition (SMD = -0.47, 95% CI [-0.81, -0.13]) and anhedonia (SMD = -0.63, 95% CI [-0.98, -0.28]). Subgroup analyses of studies that applied once daily stimulation or >10 sessions showed significantly reduced negative symptom severity.
CONCLUSION
NIBS exerts distinct effects across multiple dimensions of negative symptom, with treatment effects related to stimulation frequency and total sessions. These results need to be confirmed in dedicated studies.
Topics: Humans; Anhedonia; Brain; PubMed; Schizophrenia; Electric Stimulation Therapy
PubMed: 38432851
DOI: 10.1111/cns.14645 -
European Neuropsychopharmacology : the... Dec 2023Anhedonia is described as a decreased ability to experience rewarding and enjoyable activities, a core symptom of major depressive disorder. The sucrose preference test... (Review)
Review
Anhedonia is described as a decreased ability to experience rewarding and enjoyable activities, a core symptom of major depressive disorder. The sucrose preference test (SPT) is a widely used and reliable behavioural test to assess anhedonia in rodents, based on a two-bottle choice paradigm. To date, different protocols are in use, inducing variability between researchers and hampering comparisons between studies. We performed a systematic review of the SPT protocols used in 2021 to identify the parameters in which they differ and their potential impact. We searched a total of four databases (PubMed, Scopus, Web of Science and Science Direct), from 1st January 2021 to 31st December 2021, and screened a total of 1066 articles. After screening by title and abstract, a total of 415 articles were included in this review. We extracted and analysed the different procedures used, the type of sweet solution and the habituation, deprivation, and testing protocols. The overall quality of the studies was considered very good, however, SPT protocols were extremely variable between studies with a total of 65 different habituation protocols and 104 combinations of food/water deprivation and preference testing duration. As the SPT is one of the most used tests to assess anhedonia in rodents, this work raises awareness of the great variability in SPT protocols being currently used. Furthermore, we call for standardization in the protocol used, and overall improvement of data reporting of methodologies and results, to increase the consistency between studies and allow a better comparison of results between different labs.
Topics: Animals; Anhedonia; Depressive Disorder, Major; Food; Rodentia; Sucrose
PubMed: 37741164
DOI: 10.1016/j.euroneuro.2023.08.496 -
PsyCh Journal Apr 2024Anhedonia is a transdiagnostic symptom found in patients with schizophrenia and depression. Current pharmacological interventions for anhedonia are unsatisfactory in a... (Meta-Analysis)
Meta-Analysis Review
Anhedonia is a transdiagnostic symptom found in patients with schizophrenia and depression. Current pharmacological interventions for anhedonia are unsatisfactory in a considerable proportion of patients. There has been growing interest in applying noninvasive brain stimulation (NIBS) to patients with anhedonia. However, evidence for the efficacy of NIBS for anhedonia remain inconsistent. This study systematically identified all studies that measured anhedonia and applied NIBS in patients with schizophrenia or depression. We conducted a search using the various databases in English (PubMed, EBSCOHost (PsycInfo/PsycArticles), Web of Science) and Chinese (China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform) languages, and reviewed original research articles on NIBS published from January 1989 to July 2023. Our search had identified 15 articles for quantitative synthesis, with three concerning schizophrenia samples, 11 concerning samples with depression, and one concerning both clinical samples. We conducted a meta-analysis based on the 15 included studies, and the results suggested that NIBS could improve anhedonia symptoms in schizophrenia patients and patients with depression, with a medium-to-large effect size. Our findings are preliminary, given the limited number of included studies. Future NIBS research should measure anhedonia as a primary outcome and should recruit transdiagnostic samples.
Topics: Humans; Schizophrenia; Anhedonia; Depression; Brain; China
PubMed: 38151800
DOI: 10.1002/pchj.723 -
Antioxidants (Basel, Switzerland) Mar 2024The aging of the global population has increased the prevalence of neurodegenerative conditions. (BM), an herb with active compounds, such as bacosides A and B,... (Review)
Review
Investigating the Neuroprotective and Cognitive-Enhancing Effects of : A Systematic Review Focused on Inflammation, Oxidative Stress, Mitochondrial Dysfunction, and Apoptosis.
The aging of the global population has increased the prevalence of neurodegenerative conditions. (BM), an herb with active compounds, such as bacosides A and B, betulinic acid, loliolide, asiatic acid, and quercetin, demonstrates the potential for brain health. Limited research has been conducted on the therapeutic applications of BM in neurodegenerative conditions. This systematic review aims to project BM's beneficial role in brain disorders. BM has anti-apoptotic and antioxidant actions and can repair damaged neurons, stimulate kinase activity, restore synaptic function, improve nerve transmission, and increase neuroprotection. The included twenty-two clinical trials demonstrated that BM can reduce Nuclear Factor-κB phosphorylation, improve emotional function, cognitive functions, anhedonia, hyperactivity, sleep routine, depression, attention deficit, learning problems, memory retention, impulsivity, and psychiatric problems. Moreover, BM can reduce the levels of pro-inflammatory biomarkers and oxidative stress. Here, we highlight that BM provides notable therapeutic benefits and can serve as a complementary approach for the care of patients with neurodegenerative conditions associated with brain disorders. This review adds to the growing interest in natural products and their potential therapeutic applications by improving our understanding of the mechanisms underlying cognitive function and neurodegeneration and informing the development of new therapeutic strategies for neurodegenerative diseases.
PubMed: 38671841
DOI: 10.3390/antiox13040393 -
Psychology and Psychotherapy Jun 2024Disrupted metacognition is implicated in development and maintenance of negative symptoms, but more fine-grained analyses would inform precise treatment targeting for... (Review)
Review
BACKGROUND
Disrupted metacognition is implicated in development and maintenance of negative symptoms, but more fine-grained analyses would inform precise treatment targeting for individual negative symptoms.
AIMS
This systematic review identifies and examines datasets that test whether specific metacognitive capacities distinctly influence negative symptoms.
MATERIALS & METHODS
PsycINFO, EMBASE, Medline and Cochrane Library databases plus hand searching of relevant articles, journals and grey literature identified quantitative research investigating negative symptoms and metacognition in adults aged 16+ with psychosis. Authors of included articles were contacted to identify unique datasets and missing information. Data were extracted for a risk of bias assessment using the Quality in Prognostic Studies tool.
RESULTS
85 published reports met criteria and are estimated to reflect 32 distinct datasets and 1623 unique participants. The data indicated uncertainty about the relationship between summed scores of negative symptoms and domains of metacognition, with significant findings indicating correlation coefficients from 0.88 to -0.23. Only eight studies investigated the relationship between metacognition and individual negative symptoms, with mixed findings. Studies were mostly moderate-to-low risk of bias.
DISCUSSION
The relationship between negative symptoms and metacognition is rarely the focus of studies reviewed here, and negative symptom scores are often summed. This approach may obscure relationships between metacognitive domains and individual negative symptoms which may be important for understanding how negative symptoms are developed and maintained.
CONLCLUSION
Methodological challenges around overlapping participants, variation in aggregation of negative symptom items and types of analyses used, make a strong case for use of Individual Participant Data Meta-Analysis to further elucidate these relationships.
Topics: Humans; Metacognition; Psychotic Disorders; Adult
PubMed: 37864383
DOI: 10.1111/papt.12505 -
Frontiers in Behavioral Neuroscience 2023Cannabis is one of the most widely used psychoactive substances globally. Cannabis use can be associated with alterations of reward processing, including affective... (Review)
Review
RATIONALE
Cannabis is one of the most widely used psychoactive substances globally. Cannabis use can be associated with alterations of reward processing, including affective flattening, apathy, anhedonia, and lower sensitivity to natural rewards in conjunction with higher sensitivity to cannabis-related rewards. Such alterations have been posited to be driven by changes in underlying brain reward pathways, as per prominent neuroscientific theories of addiction. Functional neuroimaging (fMRI) studies have examined brain reward function in cannabis users via the monetary incentive delay (MID) fMRI task; however, this evidence is yet to be systematically synthesised.
OBJECTIVES
We aimed to systematically integrate the evidence on brain reward function in cannabis users examined by the MID fMRI task; and in relation to metrics of cannabis exposure (e.g., dosage, frequency) and other behavioural variables.
METHOD
We pre-registered the review in PROSPERO and reported it using PRISMA guidelines. Literature searches were conducted in PsycINFO, PubMed, Medline, CINAHL, and Scopus.
RESULTS
Nine studies were included, comprising 534 people with mean ages 16-to-28 years, of which 255 were people who use cannabis daily or almost daily, and 279 were controls. The fMRI literature to date led to largely non-significant group differences. A few studies reported group differences in the ventral striatum while participants anticipated rewards and losses; and in the caudate while participants received neutral outcomes. A few studies examined correlations between brain function and withdrawal, dosage, and age of onset; and reported inconsistent findings.
CONCLUSIONS
There is emerging but inconsistent evidence of altered brain reward function in cannabis users examined with the MID fMRI task. Future fMRI studies are required to confirm if the brain reward system is altered in vulnerable cannabis users who experience a Cannabis Use Disorder, as postulated by prominent neuroscientific theories of addiction.
PubMed: 38379938
DOI: 10.3389/fnbeh.2023.1323609 -
Translational Psychiatry Jan 2024The sucrose preference test is a popular test for anhedonia in the chronic unpredictable stress model of depression. Yet, the test does not always produce consistent... (Meta-Analysis)
Meta-Analysis
Reliability of sucrose preference testing following short or no food and water deprivation-a Systematic Review and Meta-Analysis of rat models of chronic unpredictable stress.
The sucrose preference test is a popular test for anhedonia in the chronic unpredictable stress model of depression. Yet, the test does not always produce consistent results. Long food and water deprivation before the test, while often implemented, confounds the results by introducing unwanted drives in the form of hunger and thirst. We assessed the reliability of the test when only short or no fasting was used. We searched PubMed, Embase, and Web of Science for studies in rats exposed to chronic unpredictable stress that used no more than 6 h of food and/or water deprivation before the test. Sweet consumptions, for stressed and control/antidepressant-treated animals, in 132 studies were pooled using random effects models. We found a decrease in sweet consumption in stressed rats, compared to controls, that was halved when a non-caloric sweetener was used and significantly reduced when sucrose consumption was corrected for body weight. What is more, the length of food and water deprivation was found to confound the effect. The effect was reversed when the stressed rats were treated with antidepressants. Methodological strategies meant to control for recognized sources of bias when conducting the test were often missing, and so was a clear and complete report of essential study information. Our results indicate that not only is food and water deprivation before the test unnecessary, but not recommended. Even in absence of long fasting, we found evidence of an additional effect on sweet consumption that is unrelated to anhedonia. Without properly controlling for non-hedonic drivers of consumption, the test is unreliable as a proxy measure of anhedonia. Strengthening the methodological rigor and addressing the confounding effect of metabolic factors in the sucrose preference test prevents misleading conclusions that harm the translatability of the associated research and perpetuates the use of animals for little gain.
Topics: Animals; Rats; Anhedonia; Food; Reproducibility of Results; Stress, Psychological; Sucrose; Water Deprivation
PubMed: 38242881
DOI: 10.1038/s41398-024-02742-0