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Neurology Jan 2006To evaluate neurotransmitter deficiencies and neurotransmitter-based treatments for frontotemporal dementia (FTD). (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To evaluate neurotransmitter deficiencies and neurotransmitter-based treatments for frontotemporal dementia (FTD).
METHODS
The authors conducted a systematic review of the literature on the mechanism and treatment of FTD and a meta-analysis of treatment studies of antidepressants for the behavioral symptoms of FTD.
RESULTS
Patients with FTD show deficiencies in the serotonin and dopamine neurotransmitter systems, while the acetylcholine system appears relatively intact. Antidepressant treatment significantly improves behavioral symptoms in FTD, but most studies are small and uncontrolled. Serotonergic treatments appear to improve the behavioral but not cognitive symptoms of FTD.
CONCLUSIONS
Studies of neurotransmitter deficiencies in frontotemporal dementia (FTD) can be helpful in developing treatments. Treatment studies on FTD are scarce, given the prevalence and severity of this illness. Larger, well-controlled treatment studies are required to reach more definitive conclusions about treatment efficacy. Multicenter studies are likely the best way to complete treatment studies in a timely manner.
Topics: Antidepressive Agents; Brain; Clinical Trials as Topic; Dementia; Dopamine; Dopamine Agents; Humans; Neurotransmitter Agents; Serotonin; Serotonin Receptor Agonists; Treatment Outcome
PubMed: 16401839
DOI: 10.1212/01.wnl.0000191304.55196.4d -
Sleep Attacks in Patients With Parkinson's Disease on Dopaminergic Medications: A Systematic Review.Movement Disorders Clinical Practice Dec 2014Dopaminergic medications are used as first-line treatment for Parkinson's disease (PD). In 1999, a case series was published describing 9 patients who took dopamine... (Review)
Review
Dopaminergic medications are used as first-line treatment for Parkinson's disease (PD). In 1999, a case series was published describing 9 patients who took dopamine agonists (pramipexole or ropinirole) and experienced sudden irresistible sleep attacks. Sleep attacks have subsequently been reported with other dopaminergic medications, including levodopa. Because these symptoms might not be rare and can affect health-related quality of life, we set out to review the prevalence and clinical characteristics of sleep attacks in patients with PD on dopaminergic medications. We conducted a systematic literature review using the terms parkinson* AND dopamine* AND narcolep* OR sleep attack in multiple databases (PubMed, Embase, and PsycINFO). The systematic literature review yielded 23 relevant articles, including nine case reports or case series and 14 original studies. According to the pooled data from the five studies reporting prevalence figures (n = 10,084), sleep attacks occur in 13.0% of patients with PD on dopaminergic medications. Our analysis failed to show significant differences in the Epworth Sleepiness scores between patients with and without sleep attacks (mean difference: 2.92; 95% confidence interval: -0.47-6.31). The I value of 76% indicated high heterogeneity among the studies. Sleep attacks are not a rare occurrence in patients with PD on dopamine agonist treatment. We found conflicting results on whether sleep attacks in PD resemble narcolepsy. The pathophysiology of these symptoms might be related to dopamine D2 and D4 receptor gene polymorphisms. The most effective management strategies were dose reduction and discontinuation of the offending drugs.
PubMed: 30363881
DOI: 10.1002/mdc3.12063 -
Biomolecules Jun 2022Schizophrenia has been conceptualized as a neurodevelopmental disorder with synaptic alterations and aberrant cortical-subcortical connections. Antipsychotics are the... (Review)
Review
Schizophrenia has been conceptualized as a neurodevelopmental disorder with synaptic alterations and aberrant cortical-subcortical connections. Antipsychotics are the mainstay of schizophrenia treatment and nearly all share the common feature of dopamine D2 receptor occupancy, whereas glutamatergic abnormalities are not targeted by the presently available therapies. D-amino acids, acting as N-methyl-D-aspartate receptor (NMDAR) modulators, have emerged in the last few years as a potential augmentation strategy in those cases of schizophrenia that do not respond well to antipsychotics, a condition defined as treatment-resistant schizophrenia (TRS), affecting almost 30-40% of patients, and characterized by serious cognitive deficits and functional impairment. In the present systematic review, we address with a direct and reverse translational perspective the efficacy of D-amino acids, including D-serine, D-aspartate, and D-alanine, in poor responders. The impact of these molecules on the synaptic architecture is also considered in the light of dendritic spine changes reported in schizophrenia and antipsychotics' effect on postsynaptic density proteins. Moreover, we describe compounds targeting D-amino acid oxidase and D-aspartate oxidase enzymes. Finally, other drugs acting at NMDAR and proxy of D-amino acids function, such as D-cycloserine, sarcosine, and glycine, are considered in the light of the clinical burden of TRS, together with other emerging molecules.
Topics: Amino Acids; Antipsychotic Agents; Humans; Neurobiology; Receptors, N-Methyl-D-Aspartate; Schizophrenia; Schizophrenia, Treatment-Resistant
PubMed: 35883465
DOI: 10.3390/biom12070909 -
Biological Psychiatry Oct 2019Many polymorphisms in dopamine genes are reported to affect cognitive, imaging, or clinical phenotypes. It is often inferred or assumed that such associations are... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Many polymorphisms in dopamine genes are reported to affect cognitive, imaging, or clinical phenotypes. It is often inferred or assumed that such associations are causal, mediated by a direct effect of the polymorphism on the gene product itself. However, the supporting evidence is not always clear.
METHODS
We conducted systematic reviews and meta-analyses to assess the empirical evidence for functional polymorphisms in genes encoding dopaminergic enzymes (COMT, DBH, DDC, MAOA, MAOB, and TH), dopamine receptors (DRD1, DRD2, DRD3, DRD4, and DRD5), the dopamine transporter (DAT), and vesicular transporters (VMAT1 and VMAT2). We defined functionality as an effect of the polymorphism on the expression, abundance, activity, or affinity of the gene product.
RESULTS
We screened 22,728 articles and identified 255 eligible studies. We found robust and medium to large effects for polymorphisms in 4 genes. For catechol-O-methyltransferase (COMT), the ValMet polymorphism (rs4680) markedly affected enzyme activity, protein abundance, and protein stability. Dopamine β-hydroxylase (DBH) activity was associated with rs1611115, rs2519152, and the DBH-STR polymorphism. Monoamine oxidase A (MAOA) activity was associated with a 5' VNTR polymorphism. Dopamine D receptor (DRD2) binding was influenced by the Taq1A (rs1800497) polymorphism, and rs1076560 affected DRD2 splicing.
CONCLUSIONS
Some widely studied dopaminergic polymorphisms clearly and substantially affect the abundance or activity of the encoded gene product. However, for other polymorphisms, evidence of such an association is negative, inconclusive, or lacking. These findings are relevant when selecting polymorphisms as "markers" of dopamine function, and for interpreting the biological plausibility of associations between these polymorphisms and aspects of brain function or dysfunction.
Topics: Brain; Dopamine; Dopamine Plasma Membrane Transport Proteins; Humans; Polymorphism, Single Nucleotide; Receptors, Dopamine
PubMed: 31303260
DOI: 10.1016/j.biopsych.2019.05.014 -
Addiction Biology May 2020Genetics account for moderate variation of individual differences in developing alcohol use disorder (AUD), but it is unclear which genetic variations contribute to AUD... (Meta-Analysis)
Meta-Analysis
Genetics account for moderate variation of individual differences in developing alcohol use disorder (AUD), but it is unclear which genetic variations contribute to AUD risk. One candidate gene investigated due to its association with AUD is the dopamine D4 receptor gene (DRD4), which contains a 48-base pair variable number tandem repeat (VNTR) in exon 3 of its coding region. To date, no quantitative synthesis of the published literature on the effects of DRD4 VNTR variation on alcohol-related phenotypes has been conducted. MEDLINE, Embase, Web of Science, and PsycInfo were searched for studies that reported on alcohol craving, alcohol consumption, severity of AUD, and case-control (AUD versus no diagnosis of AUD) studies in DRD4L (seven repeats or more) carriers compared with DRD4S (six repeats or less) homozygotes. Random-effects meta-analysis was used for all analyses. A pooled sample size of 655 to 13,360 of 28 studies were included. Compared with DRD4S homozygotes, DRD4L carriers had increased number of drinking days (SMD: 0.205; 95% CI: 0.008 to 0.402), binge drinking days (SMD: 0.217; 95% CI: 0.0532 to 0.380), and severity of AUD (SMD: 0.143; 95% CI: 0.028 to 0.259). There was no difference between DRD4 VNTR genotypes on drinks per drinking day, largest number of drinks per day/occasion, and case-control analysis. It was not possible to conduct a meta-analysis of the craving data, but a systematic review of this literature found mixed results on DRD4 VNTR genotype effect. The present meta-analysis suggests DRD4 VNTR variation may be a risk factor for problematic alcohol use. Our findings are limited, however, by the absence of ancestry data from studies included in our analysis, precluding our ability to adjust for population stratification. Due to the likelihood of type I error in candidate gene approaches, our work highlights the critical need for studies with larger and more inclusive samples that account for sex and genetic ancestry to fully understand this relationship.
Topics: Alcohol Drinking; Alcoholism; Binge Drinking; Craving; Humans; Minisatellite Repeats; Receptors, Dopamine D4
PubMed: 31149768
DOI: 10.1111/adb.12770 -
The Cochrane Database of Systematic... Jan 2018Tardive dyskinesia (TD) is a disabling movement disorder associated with the prolonged use of antipsychotic medication. Several strategies have been examined in the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Tardive dyskinesia (TD) is a disabling movement disorder associated with the prolonged use of antipsychotic medication. Several strategies have been examined in the treatment of TD. Currently, however, there is no clear evidence of the effectiveness of these drugs in TD and they have been associated with many side effects. One particular strategy would be to use pharmaceutical agents which are known to influence the catecholaminergic system at various junctures.
OBJECTIVES
1. To determine the effects of any of the following drugs for antipsychotic-induced TD in people with schizophrenia or other chronic mental illnesses.i. Drugs which influence the noradrenergic system.ii. Dopamine receptor agonists.iii. Dopamine receptor antagonists.iv. Dopamine-depletor drugs.v. Drugs that increase the production or release of dopamine.2. To examine whether any improvement occurred with short periods of intervention (less than 6 weeks) and, if this did occur, whether this effect was maintained at longer periods of follow-up.3. To examine if there was a differential effect for the various compounds.4. To examine whether the use of non-antipsychotic catecholaminergic drugs are most effective in those with more recent onset TD (less than five years).
SEARCH METHODS
We retrieved 712 references from searching the Cochrane Schizophrenia Group Trials Register (July 2015 and April 2017). We also inspected references of all identified studies for further trials and contacted authors of trials for additional information.
SELECTION CRITERIA
We selected studies if they were randomised controlled trials focusing on people with schizophrenia or other chronic mental illnesses and antipsychotic-induced tardive dyskinesia. We compared the use of catecholaminergic interventions versus placebo, no intervention, or any other intervention for the treatment of antipsychotic-induced tardive dyskinesia.
DATA COLLECTION AND ANALYSIS
We independently extracted data from these trials and we estimated risk ratios (RRs) with 95% confidence intervals (CIs). We assumed that people who left the studies early had no improvement.
MAIN RESULTS
There are 10 included trials (N = 261) published between 1973 and 2010; eight are new from the 2015 and 2017 update searches. Forty-eight studies are excluded. Participants were mostly chronically mentally ill inpatients in their 50s, and studies were primarily of short (2 to 6 weeks) duration. The overall risk of bias in these studies was unclear, mainly due to poor reporting of allocation concealment and generation of the sequence. Studies were also not clearly blinded and we are unsure if data are incomplete or selectively reported, or if other biases were operating.One small, three-arm trial found that both alpha-methyldopa (N = 20; RR 0.33, 95% CI 0.14 to 0.80; low-quality evidence) and reserpine (N = 20; RR 0.52 95% CI 0.29 to 0.96; low-quality evidence) may lead to a clinically important improvement in tardive dyskinesia symptoms compared with placebo after 2 weeks' treatment, but found no evidence of a difference between alpha-methyldopa and reserpine (N = 20; RR 0.60, 95% CI 0.19 to 1.86; very low quality evidence). Another small trial compared tetrabenazine and haloperidol after 18 weeks' treatment and found no evidence of a difference on clinically important improvement in tardive dyskinesia symptoms (N = 13; RR 0.93, 95% CI 0.45 to 1.95; very low quality evidence). No study reported on adverse events.For remaining outcomes there was no evidence of a difference between any of the interventions: alpha-methyldopa versus placebo for deterioration of tardive dyskinesia symptoms (1 RCT; N = 20; RR 0.33, 95% CI 0.02 to 7.32; very low quality evidence), celiprolol versus placebo for leaving the study early (1 RCT; N = 35; RR 5.28, 95% CI 0.27 to 102.58; very low quality evidence) and quality of life (1 RCT; N = 35; RR 0.87, 95% CI 0.68 to 1.12; very low quality evidence), alpha-methyldopa versus reserpine for deterioration of tardive dyskinesia symptoms (1 RCT; N = 20; not estimable, no reported events; very low quality evidence), reserpine or carbidopa/levodopa versus placebo for deterioration of tardive dyskinesia symptoms (2 RCTs; N = 37; RR 1.18, 95% CI 0.35 to 3.99; very low quality evidence), oxypertine versus placebo for deterioration of mental state (1 RCT; N = 42; RR 2.20, 95% CI 0.22 to 22.45; very low quality evidence), dopaminergic drugs (amantadine, bromocriptine, tiapride, oxypertine, carbidopa/levodopa) versus placebo for leaving the study early (6 RCTs; N = 163; RR 1.29, 95% CI 0.65 to 2.54; very low quality evidence), and tetrabenazine versus haloperidol for deterioration of tardive dyskinesia symptoms (1 RCT; N = 13; RR 1.17, 95% CI 0.09 to 14.92) and leaving the study early (1 RCT; N = 13; RR 0.23, 95% CI 0.01 to 4.00).
AUTHORS' CONCLUSIONS
Although there has been a large amount of research in this area, many studies were excluded due to inherent problems in the nature of their cross-over designs. Usually data are not reported before the cross-over and the nature of TD and its likely response to treatments make it imprudent to use this data. The review provides little usable information for service users or providers and more well-designed and well-reported studies are indicated.
Topics: Adrenergic Uptake Inhibitors; Anti-Dyskinesia Agents; Antipsychotic Agents; Celiprolol; Disease Progression; Dopamine Antagonists; Dyskinesia, Drug-Induced; Haloperidol; Humans; Methyldopa; Randomized Controlled Trials as Topic; Reserpine; Tetrabenazine; Tiapamil Hydrochloride
PubMed: 29342497
DOI: 10.1002/14651858.CD000458.pub3 -
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 -
Schizophrenia Bulletin Nov 2016Although weight gain is a serious but variable adverse effect of antipsychotics that has genetic underpinnings, a comprehensive meta-analysis of pharmacogenetics of... (Meta-Analysis)
Meta-Analysis Review
Although weight gain is a serious but variable adverse effect of antipsychotics that has genetic underpinnings, a comprehensive meta-analysis of pharmacogenetics of antipsychotic-related weight gain is missing. In this review, random effects meta-analyses were conducted for dominant and recessive models on associations of specific single nucleotide polymorphisms (SNP) with prospectively assessed antipsychotic-related weight or body mass index (BMI) changes (primary outcome), or categorical increases in weight or BMI (≥7%; secondary outcome). Published studies, identified via systematic database search (last search: December 31, 2014), plus 3 additional cohorts, including 222 antipsychotic-naïve youth, and 81 and 141 first-episode schizophrenia adults, each with patient-level data at 3 or 4 months treatment, were meta-analyzed. Altogether, 72 articles reporting on 46 non-duplicated samples (n = 6700, mean follow-up = 25.1wk) with 38 SNPs from 20 genes/genomic regions were meta-analyzed (for each meta-analysis, studies = 2-20, n = 81-2082). Eleven SNPs from 8 genes were significantly associated with weight or BMI change, and 4 SNPs from 2 genes were significantly associated with categorical weight or BMI increase. Combined, 13 SNPs from 9 genes (Adrenoceptor Alpha-2A [ADRA2A], Adrenoceptor Beta 3 [ADRB3], Brain-Derived Neurotrophic Factor [BDNF], Dopamine Receptor D2 [DRD2], Guanine Nucleotide Binding Protein [GNB3], 5-Hydroxytryptamine (Serotonin) Receptor 2C [HTR2C], Insulin-induced gene 2 [INSIG2], Melanocortin-4 Receptor [MC4R], and Synaptosomal-associated protein, 25kDa [SNAP25]) were significantly associated with antipsychotic-related weight gain (P-values < .05-.001). SNPs in ADRA2A, DRD2, HTR2C, and MC4R had the largest effect sizes (Hedges' g's = 0.30-0.80, ORs = 1.47-1.96). Less prior antipsychotic exposure (pediatric or first episode patients) and short follow-up (1-2 mo) were associated with larger effect sizes. Individual antipsychotics did not significantly moderate effect sizes. In conclusion, antipsychotic-related weight gain is polygenic and associated with specific genetic variants, especially in genes coding for antipsychotic pharmacodynamic targets.
Topics: Antipsychotic Agents; Humans; Pharmacogenetics; Psychotic Disorders; Weight Gain
PubMed: 27217270
DOI: 10.1093/schbul/sbw058 -
Journal of Clinical Psychopharmacology Feb 2016In the last 10 years, dopamine replacement therapy (DRT) has become a well-known risk factor for developing an impulse control disorder, such as gambling disorder (GD).... (Review)
Review
BACKGROUND
In the last 10 years, dopamine replacement therapy (DRT) has become a well-known risk factor for developing an impulse control disorder, such as gambling disorder (GD). Another medication, aripiprazole (ARI), has been more recently identified as another risk factor. Dopamine replacement therapy and ARI share a dopamine agonist action. Our work aimed at comparing patients with PG according to their treatment with DRT or ARI.
METHODS
Two methods were combined-a systematic review concentrated on case reports and the analysis of a French disordered gamblers cohort focused on patients using ARI or DRT at inclusion.
RESULTS
We reported 48 cases of GD possibly due to DRT and 17 cases of GD possibly due to ARI. Because of their standardized assessment, only the EVALJEU patients could be compared. Two clinical patterns emerged. Patients in the ARI group were young, impulsive, and high novelty seekers and had a history of substance misuse. Their first gambling experience occurred during adolescence. Conversely, patients in the DRT group were old, and they began gambling late in life. They showed low levels of gambling-related cognition.
CONCLUSIONS
Patients in the ARI group seemed to be more severe pathological gamblers than patients in the DRT group. Aripiprazole is a partial D2 receptor agonist, whereas DRT includes full D2 receptor agonist. The trigger mechanism of PG development is complex and cannot only be attributed only to the pharmacodynamic effects of dopaminergic drugs. Indeed, individual vulnerability factors and environmental factors need to be considered.
Topics: Adolescent; Aripiprazole; Disruptive, Impulse Control, and Conduct Disorders; Dopamine Agonists; Gambling; Humans; Receptors, Dopamine D2; Risk Factors
PubMed: 26658263
DOI: 10.1097/JCP.0000000000000444 -
Neuropsychopharmacology : Official... Mar 2019Use of alcohol, cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs. The exact pathophysiology of abuse or... (Meta-Analysis)
Meta-Analysis
Use of alcohol, cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs. The exact pathophysiology of abuse or addiction associated with these sedative substances is not completely understood, but previous research implicates the important role of the striatal dopamine system in the addiction process. Multiple studies investigated changes in the striatal dopamine systems of users of sedative substances, but currently these results are very heterogeneous. Therefore, we conducted a meta-analysis of in vivo neuroimaging studies investigating dopaminergic alterations in the striatum of users of alcohol, opioids or cannabis. Analyses for each substance were conducted separately for the availability of D2/D3 dopamine receptors, dopamine transporters and dopamine synthesis capacity. In total, 723 substance users and 752 healthy controls were included. The results indicated a significant lower striatal D2/D3 receptor availability in alcohol users compared to controls (g = 0.46) but no difference in dopamine transporter availability or dopamine synthesis capacity. Our analysis indicated that changes of dopamine receptors and transporters are moderated by the duration of abstinence. Comparing opioid users with controls revealed a significant lower D2/D3 receptor availability (g = 1.17) and a significantly lower transporter availability (g = 1.55) in opioid users. For cannabis users, there was no significant difference in receptor availability compared to controls and too few studies provided information on dopamine transporter availability or synthesis capacity. Our analysis provides strong evidence for a central role of the striatal dopamine system in use of alcohol or opioids. Further studies are needed to clarify the impact of the dopamine system in cannabis users.
Topics: Alcoholism; Corpus Striatum; Dopamine Plasma Membrane Transport Proteins; Humans; Marijuana Abuse; Neuroimaging; Opioid-Related Disorders; Receptors, Dopamine D2; Receptors, Dopamine D3
PubMed: 30188512
DOI: 10.1038/s41386-018-0191-9