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European Journal of Neurology Aug 2023Tremor is often perceived as severely disabling by patients with idiopathic Parkinson's disease (iPD) and yet ranges among the most difficult symptoms to treat. To date,... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Tremor is often perceived as severely disabling by patients with idiopathic Parkinson's disease (iPD) and yet ranges among the most difficult symptoms to treat. To date, no comprehensive analysis of non-lesional therapies to manage tremor in iPD exists to base recommendations upon. We therefore present a systematic literature review and meta-analysis assessing the efficacy/effectiveness and safety of non-lesional treatments for tremor in iPD.
METHODS
Three electronic databases were searched using a combination of title/abstract keywords complemented by hand-searching of reference lists. A random-effects meta-analysis of standardized mean change scores was conducted where appropriate.
RESULTS
Some 114 studies met inclusion criteria involving 8045 patients. The meta-analysis revealed an overall reduction of standardized mean change scores by (-0.93 [CI: -1.42; -0.43], p < 0.001) by 14 different dopaminergic and non-dopaminergic classes of agents. No significant differences were identified between direct comparisons. Subgroup analysis comparing dopamine receptor agonists resulted in superior effects of pramipexole and rotigotine compared with ropinirole. There was little cumulative evidence to support the use of individual non-pharmacological interventions for tremor, except for electrical stimulation.
CONCLUSIONS
The results of this meta-analysis suggest a large but nonspecific effect of established pharmacological therapies on tremor in iPD. Based on high-quality studies, there is sufficient evidence to support that levodopa, dopamine receptor agonists, and monoamine oxidase inhibitors provide tremor relief in most patients, while evidence supporting other treatments is less well established. Sufficient evidence to draw conclusions on effects of non-lesional treatments in cases with refractory tremor is lacking.
Topics: Humans; Parkinson Disease; Dopamine Agonists; Antiparkinson Agents; Tremor; Levodopa
PubMed: 37154268
DOI: 10.1111/ene.15823 -
Tremor and Other Hyperkinetic Movements... 2024Tardive Dyskinesia (TD) is a neurological disorder characterized by involuntary movements, often caused by dopamine receptor antagonists. Vesicular Monoamine Transporter... (Comparative Study)
Comparative Study Review
BACKGROUND
Tardive Dyskinesia (TD) is a neurological disorder characterized by involuntary movements, often caused by dopamine receptor antagonists. Vesicular Monoamine Transporter 2 (VMAT2) inhibitors, such as valbenazine and deutetrabenazine, have emerged as promising therapies for TD and several clinical trials have shown their efficacy. This study aims to compare the efficacy and safety profile of VMAT2 inhibitors, focusing on a recent trial conducted in the Asian population.
METHODS
We reviewed the PubMed, Cochrane Library, Embase database, and clinicaltrials.gov between January 2017 and October 2023, using the keywords "tardive dyskinesia" AND ("valbenazine" [all fields] OR " deutetrabenazine " [all fields]) AND "clinical trial". The reviewed articles were studied for efficacy and side effects.
RESULTS
An initial search yielded 230 articles, of which 104 were duplicates. Following the title and abstract screening, 25 additional articles were excluded. A full-text review resulted in the exclusion of 96 more articles. Ultimately, four double-blind clinical trials met the inclusion criteria. The deutetrabenazine studies demonstrated significant improvements in Abnormal Involuntary Movement Scale (AIMS) scores compared to placebo, with no difference in adverse events. The valbenazine studies showed favorable results in reducing TD symptoms and were well-tolerated.
DISCUSSION
The studies reviewed in this analysis underscore the potential of deutetrabenazine and valbenazine as valuable treatment options for TD in diverse populations. Both medications demonstrated significant improvements in AIMS scores, suggesting their effectiveness in managing TD symptoms. Additionally, they exhibited favorable safety profiles, with low rates of serious adverse events and no significant increase in QT prolongation, parkinsonism, suicidal ideation, or mortality.
CONCLUSION
The studies reviewed highlight the promising efficacy and tolerability of deutetrabenazine and valbenazine as treatments for Tardive Dyskinesia, providing new hope for individuals affected by this challenging condition.
Topics: Humans; Randomized Controlled Trials as Topic; Tardive Dyskinesia; Tetrabenazine; Valine; Vesicular Monoamine Transport Proteins
PubMed: 38497033
DOI: 10.5334/tohm.842 -
Journal of Psychiatry & Neuroscience :... 2024Transcranial magnetic stimulation (TMS) is a noninvasive neurostimulation modality that has been used to study human synaptic plasticity. Leveraging work in ex vivo...
BACKGROUND
Transcranial magnetic stimulation (TMS) is a noninvasive neurostimulation modality that has been used to study human synaptic plasticity. Leveraging work in ex vivo preparations, mechanistically informed pharmacological adjuncts to TMS have been used to improve our fundamental understanding of TMS-induced synaptic plasticity.
METHODS
We systematically reviewed the literature pairing pharmacological adjuncts with TMS plasticity-induction protocols in humans. We searched MEDLINE, PsycINFO, and Embase from 2013 to Mar. 10, 2023. Studies published before 2013 were extracted from a previous systematic review. We included studies using repetitive TMS, theta-burst stimulation, paired associative stimulation, and quadripulse stimulation paradigms in healthy and clinical populations.
RESULTS
Thirty-six studies met our inclusion criteria (28 in healthy and 8 in clinical populations). Most pharmacological agents have targeted the glutamatergic -methyl-d-aspartate (NMDA; 15 studies) or dopamine receptors (13 studies). The NMDA receptor is necessary for TMS-induced plasticity; however, sufficiency has not been shown across protocols. Dopaminergic modulation of TMS-induced plasticity appears to be dose-dependent. The GABAergic, cholinergic, noradrenergic, and serotonergic neurotransmitter systems have small evidence bases supporting modulation of TMS-induced plasticity, as do voltage-gated calcium and sodium channels. Studies in clinical populations suggest that pharmacological adjuncts to TMS may rescue motor cortex plasticity, with implications for therapeutic applications of TMS and a promising clinical trial in depression.
LIMITATIONS
This review is limited by the predominance in the literature of studies with small sample sizes and crossover designs.
CONCLUSION
Pharmacologically enhanced TMS largely parallels findings from ex vivo preparations. As this area expands and novel targets are tested, adequately powered samples in healthy and clinical populations will inform the mechanisms of TMS-induced plasticity in health and disease.
Topics: Humans; Transcranial Magnetic Stimulation; Neuronal Plasticity; Motor Cortex; Dopamine; Calcium; Evoked Potentials, Motor
PubMed: 38359933
DOI: 10.1503/jpn.230090 -
Molecular Psychiatry May 2024The dopamine hypothesis of schizophrenia posits that elevated striatal dopamine functioning underlies the development of psychotic symptoms. Chronic exposure to social...
The dopamine hypothesis of schizophrenia posits that elevated striatal dopamine functioning underlies the development of psychotic symptoms. Chronic exposure to social stressors increases psychosis risk, possibly by upregulating striatal dopamine functioning. Here we systematically review single photon emission computed tomography (SPECT) and positron emission tomography (PET) studies that examined the relationship between chronic social stress exposure and in vivo striatal dopamine functioning in humans. We searched the scientific databases PubMed and PsycINFO from inception to August 2023. The quality of the included studies was evaluated with the ten-item Observational Study Quality Evaluation (PROSPERO: CRD42022308883). Twenty-eight studies were included, which measured different aspects of striatal dopamine functioning including dopamine synthesis capacity (DSC), vesicular monoamine transporter type 2 binding, dopamine release following a pharmacological or behavioral challenge, D receptor binding, and dopamine transporter binding. We observed preliminary evidence of an association between childhood trauma and increased striatal DSC and dopamine release. However, exposure to low socioeconomic status, stressful life events, or other social stressors was not consistently associated with altered striatal dopamine functioning. The quality of available studies was generally low. In conclusion, there is insufficient evidence that chronic social stressors upregulate striatal dopamine functioning in humans. We propose avenues for future research, in particular to improve the measurement of chronic social stressors and the methodological quality of study designs.
PubMed: 38760501
DOI: 10.1038/s41380-024-02581-x -
BMJ Neurology Open 2024The aim of this manuscript is to review the evidence and compare the efficacy and safety of catechol-O-methyltransferase inhibitors (COMT-Is), dopamine receptor agonists...
BACKGROUND
The aim of this manuscript is to review the evidence and compare the efficacy and safety of catechol-O-methyltransferase inhibitors (COMT-Is), dopamine receptor agonists (DRAs) and monoamine-oxidase B inhibitors (MAOB-Is) as adjunctive treatment to levodopa in patients with Parkinson's disease (PD) experiencing motor complications.
METHODS
In this systematic review and network meta-analysis, literature searches were performed in MEDLINE and Embase to identify eligible randomised controlled trials (RCTs) with a minimal follow-up of at least 4 weeks published in English between 1980 and 2021. RCTs were included if either a COMT-I, DRA or MAOB-I was evaluated as an adjunctive therapy to levodopa in patients with PD experiencing motor complications and dyskinesia. The main outcomes included daily off-medication time, motor and non-motor examination scales, and adverse events including dyskinesia.
RESULTS
74 RCTs reporting on 18 693 patients were included. All three studied drug classes decreased daily off-medication time compared with placebo (COMT-Is mean -0.8 hours (95% CI -1.0 to -0.6), DRAs -1.1 hours (95% CI -1.4 to -0.8), MAOB-Is -0.9 hours (95% CI -1.2 to -0.6)). Safety analysis showed an increased risk of dyskinesia for all three drug classes (COMT-Is OR 3.3 (95% CI 2.7 to 4.0), DRAs 3.0 (95% CI 2.5 to 3.5), MAOB-Is 1.6 (95% CI 1.2 to 2.2)). According to surface under the cumulative ranking curve scores, pramipexole IR was associated with the most favourable benefit-risk profile.
CONCLUSIONS
COMT-Is, DRAs and MAOB-Is effectively reduce motor complications and increase incidence of dyskinesia. In the network meta-analysis, adjunctive use of DRAs appeared most effective.
PubMed: 38352047
DOI: 10.1136/bmjno-2023-000573 -
Translational Psychiatry Jun 2024Excessive and persistent aggressiveness is the most common behavioral problem that leads to psychiatric referrals among children. While half of the variance in childhood...
Excessive and persistent aggressiveness is the most common behavioral problem that leads to psychiatric referrals among children. While half of the variance in childhood aggression is attributed to genetic factors, the biological mechanism and the interplay between genes and environment that results in aggression remains elusive. The purpose of this systematic review is to provide an overview of studies examining the genetics of childhood aggression irrespective of psychiatric diagnosis. PubMed, PsycINFO, and MEDLINE databases were searched using predefined search terms for aggression, genes and the specific age group. From the 652 initially yielded studies, eighty-seven studies were systematically extracted for full-text review and for further quality assessment analyses. Findings show that (i) investigation of candidate genes, especially of MAOA (17 studies), DRD4 (13 studies), and COMT (12 studies) continue to dominate the field, although studies using other research designs and methods including genome-wide association and epigenetic studies are increasing, (ii) the published articles tend to be moderate in sizes, with variable methods of assessing aggressive behavior and inconsistent categorizations of tandem repeat variants, resulting in inconclusive findings of genetic main effects, gene-gene, and gene-environment interactions, (iii) the majority of studies are conducted on European, male-only or male-female mixed, participants. To our knowledge, this is the first study to systematically review the effects of genes on youth aggression. To understand the genetic underpinnings of childhood aggression, more research is required with larger, more diverse sample sets, consistent and reliable assessments and standardized definition of the aggression phenotypes. The search for the biological mechanisms underlying child aggression will also benefit from more varied research methods, including epigenetic studies, transcriptomic studies, gene system and genome-wide studies, longitudinal studies that track changes in risk/ameliorating factors and aggression-related outcomes, and studies examining causal mechanisms.
Topics: Child; Female; Humans; Male; Aggression; Catechol O-Methyltransferase; Gene-Environment Interaction; Genome-Wide Association Study; Monoamine Oxidase; Receptors, Dopamine D4
PubMed: 38862490
DOI: 10.1038/s41398-024-02870-7 -
Biomedical Reports Jun 2024Lurasidone is an atypical anti-psychotic approved by the US Food and Drug Administration. It is mainly used to treat schizophrenia in adults through its antagonistic...
Efficacy and safety of lurasidone for schizophrenia: A systematic review and meta‑analysis of eight short‑term, randomized, double‑blind, placebo‑controlled clinical trials.
Lurasidone is an atypical anti-psychotic approved by the US Food and Drug Administration. It is mainly used to treat schizophrenia in adults through its antagonistic action on dopamine and 5-hydroxytryptamine receptors. The present study systematically assessed the efficacy and safety of lurasidone in the treatment of schizophrenia. Clinical, double-blind, parallel, randomized controlled trials (RCTs) of lurasidone in the treatment of schizophrenia were retrieved from PubMed\Medline, EBSCO, Embase, Cochrane Library, OVID, Web of Science and related clinical trial registration websites up to May 2023. A total of two investigators independently screened the included references and evaluated their quality. RevMan 5.3 software was used for meta-analysis of each measure outcome. The present systematic review was registered in PROSPERO (ID=CRD42018108178). A total of eight RCTs were included in the present study, including a total of 2,456 patients with schizophrenia. All eight references were randomized, double-blind and parallel control trials. All eight references were evaluated as high quality. The meta-analysis results demonstrated that there were no significant change in total Positive and Negative Syndrome Scale (PANSS) score, Clinical Global Impression of Severity (CGI-S) score and Montgomery-Asberg Depression Rating Scale (MADRS) between the 40 mg lurasidone group and the placebo group (P>0.05). However, as the dosage increased, the 80, 120 and 160 mg lurasidone groups had significant changes in total PANSS score, CGI-S score and MADRS Compared with placebo (P<0.05), although changes in MADRS in the 120 mg lurasidone group were not statistically significant (P>0.05). In terms of safety, the changes in the incidence of agitation in the 40 mg lurasidone group (P<0.05), vomiting in the 80 mg group (P<0.05) and akathisia in the 160 mg group (P<0.05) were statistically significant and there were also statistically significant changes in the incidence of akathisia, nausea, somnolence and extrapyramidal disorder among the 40, 80 and 120 mg lurasidone groups (P<0.05); No statistically significant changes in the in the incidence of other adverse reactions (P>0.05). In conclusion, existing evidence suggests that the initial dose of lurasidone for schizophrenia can be adjusted to 80 mg. As the condition aggravates, the dose can be incrementally increased to 160 mg. A dose of 160 mg lurasidone is recommended as the most efficacious and safe dose for acute schizophrenia and the risk of occurrence of akathisia, nausea, somnolence and extrapyramidal disorder is still high when lurasidone is administered at a dose of 80-120 mg. The dose should be promptly adjusted or the drug should be withdrawn if the aforementioned adverse reactions worsen. Multi-center, high-quality and long-term clinical RCTs influenced by the included references are still necessary to support the aforementioned conclusions.
PubMed: 38682090
DOI: 10.3892/br.2024.1779 -
Journal of Clinical PsychopharmacologyIncreasing evidence suggests an association between third-generation antipsychotics (TGAs) and impulse control disorders (ICDs). This is thought to be due to their... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Increasing evidence suggests an association between third-generation antipsychotics (TGAs) and impulse control disorders (ICDs). This is thought to be due to their partial agonism of dopamine receptors. However, neither the relative nor absolute risks of ICDs in those prescribed TGAs are well established. To inform clinical practice, this systematic review and meta-analysis summarizes and quantifies the current evidence for an association.
METHODS
An electronic search of Medline, PsychINFO, EMBASE, and the Cochrane Clinical Trials Database was undertaken from database inception to November 2022. Three reviewers screened abstracts and reviewed full texts for inclusion. A random-effects meta-analysis was conducted with eligible studies.
RESULTS
A total of 392 abstracts were retrieved, 214 remained after duplicates were removed. Fifteen full texts were reviewed, of which 8 were included. All 8 studies found that TGAs were associated with increased probability of ICDs. Risk of bias was high or critical in 7 of 8 studies. Three studies were included in the pooled analysis for the primary outcome, 2 with data on each of aripiprazole, cariprazine, and brexpiprazole. Exposure to TGAs versus other antipsychotics was associated with an increase in ICDs (pooled odds ratio, 5.54; 2.24-13.68). Cariprazine and brexpiprazole were significantly associated with ICDs when analyzed individually. Aripiprazole trended toward increased risk, but very wide confidence intervals included no effect.
CONCLUSIONS
Third-generation antipsychotics were associated with increased risk of ICDs in all studies included and pooled analysis. However, the risk of bias is high, confidence intervals are wide, and the quality of evidence is very low for all TGAs examined.
Topics: Humans; Antipsychotic Agents; Aripiprazole; Disruptive, Impulse Control, and Conduct Disorders; Risk Factors
PubMed: 38011021
DOI: 10.1097/JCP.0000000000001773 -
The European Journal of Neuroscience Mar 2024Dopamine, a catecholamine neurotransmitter, has historically been associated with the encoding of reward, whereas its role in aversion has received less attention. Here,...
Dopamine, a catecholamine neurotransmitter, has historically been associated with the encoding of reward, whereas its role in aversion has received less attention. Here, we systematically gathered the vast evidence of the role of dopamine in the simplest forms of aversive learning: classical fear conditioning and extinction. In the past, crude methods were used to augment or inhibit dopamine to study its relationship with fear conditioning and extinction. More advanced techniques such as conditional genetic, chemogenic and optogenetic approaches now provide causal evidence for dopamine's role in these learning processes. Dopamine neurons encode conditioned stimuli during fear conditioning and extinction and convey the signal via activation of D receptor sites particularly in the amygdala, prefrontal cortex and striatum. The coordinated activation of dopamine receptors allows for the continuous formation, consolidation, retrieval and updating of fear and extinction memory in a dynamic and reciprocal manner. Based on the reviewed literature, we conclude that dopamine is crucial for the encoding of classical fear conditioning and extinction and contributes in a way that is comparable to its role in encoding reward.
Topics: Dopamine; Extinction, Psychological; Conditioning, Classical; Fear; Prefrontal Cortex; Avoidance Learning
PubMed: 37848184
DOI: 10.1111/ejn.16157 -
Asian Journal of Psychiatry May 2024Cariprazine is an orally active dopamine D3-preferring D3/D2 receptor and serotonin 5-HT1A receptor partial agonist, being considered as a treatment for refractory MDD.... (Meta-Analysis)
Meta-Analysis Review
Role of adjunctive cariprazine for treatment-resistant depression in patients with major depressive disorder: A systematic review and meta-analysis of randomized controlled trials.
INTRODUCTION
Cariprazine is an orally active dopamine D3-preferring D3/D2 receptor and serotonin 5-HT1A receptor partial agonist, being considered as a treatment for refractory MDD. Therefore, we aim to perform the first meta-analysis of current literature, to collate changes in depression from baseline and assess tolerability of adjunctive cariprazine in MDD populace.
METHODS
PubMed, Embase, Google Scholar, ClinicalTrials.Gov, and Cochrane Library were searched from inception till 1st September 2023. RCTs of adult patients with refractory MDD under adjunctive cariprazine vs. placebo were included. Primary outcomes included improvement in MADRS, CGI-S, and HAM-D 17 scores. Secondary outcomes included treatment-emergent adverse events. The statistical analysis was performed using generic inverse variance with random-effects model. The overall risk ratios (RR) were calculated for dichotomous outcomes.
RESULTS
A total of five RCTs were analysed, enrolling 2013 participants (cariprazine: 959 participants, Placebo: 1054). Supplementation of ADT with cariprazine demonstrated a significant improvement in MADRAS, CGI-S and HAMD-17 scores from baseline (LSMD: -1.88, 95% CI [-2.94, -0.83], p=0.0005), (LSMD: -0.18, 95% CI [-0.29, -0.07], p=0.002), and (LSMD: -0.96, 95% CI [-1.70, -0.21], p=0.01) respectively. Treatment with adjunctive cariprazine therapy demonstrated significantly increased incidence of akathisia, nausea, dizziness, fatigue, restlessness, somnolence, and tremors when compared with placebo.
CONCLUSION
Our meta-analysis provides evidence supporting the efficacy of adjunctive cariprazine in patients with refractory MDD. However, it is essential to consider the safety profile of cariprazine, particularly the increased risk of adverse events. The vigilant monitoring and management of these side effects should be integrated into clinical practice to minimize discontinuation rates and optimize patient outcomes.
Topics: Humans; Randomized Controlled Trials as Topic; Depressive Disorder, Major; Depressive Disorder, Treatment-Resistant; Piperazines; Drug Therapy, Combination; Antidepressive Agents; Outcome Assessment, Health Care
PubMed: 38513509
DOI: 10.1016/j.ajp.2024.104005