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Translational Psychiatry Mar 2016The D2 dopamine receptor mediates neuropsychiatric symptoms and is a target of pharmacotherapy. Inter-individual variation of D2 receptor density is thought to influence... (Meta-Analysis)
Meta-Analysis Review
The D2 dopamine receptor mediates neuropsychiatric symptoms and is a target of pharmacotherapy. Inter-individual variation of D2 receptor density is thought to influence disease risk and pharmacological response. Numerous molecular imaging studies have tested whether common genetic variants influence D2 receptor binding potential (BP) in humans, but demonstration of robust effects has been limited by small sample sizes. We performed a systematic search of published human in vivo molecular imaging studies to estimate effect sizes of common genetic variants on striatal D2 receptor BP. We identified 21 studies examining 19 variants in 11 genes. The most commonly studied variant was a single-nucleotide polymorphism in ANKK1 (rs1800497, Glu713Lys, also called 'Taq1A'). Fixed- and random-effects meta-analyses of this variant (5 studies, 194 subjects total) revealed that striatal BP was significantly and robustly lower among carriers of the minor allele (Lys713) relative to major allele homozygotes. The weighted standardized mean difference was -0.57 under the fixed-effect model (95% confidence interval=(-0.87, -0.27), P=0.0002). The normal relationship between rs1800497 and BP was not apparent among subjects with neuropsychiatric diseases. Significant associations with baseline striatal D2 receptor BP have been reported for four DRD2 variants (rs1079597, rs1076560, rs6277 and rs1799732) and a PER2 repeat polymorphism, but none have yet been tested in more than two independent samples. Our findings resolve apparent discrepancies in the literature and establish that rs1800497 robustly influences striatal D2 receptor availability. This genetic variant is likely to contribute to important individual differences in human striatal function, neuropsychiatric disease risk and pharmacological response.
Topics: Brain; Genetic Variation; Humans; Molecular Imaging; Positron-Emission Tomography; Receptors, Dopamine D2; Tomography, Emission-Computed, Single-Photon
PubMed: 26926883
DOI: 10.1038/tp.2016.22 -
Journal of the Endocrine Society Oct 2021Surgical management of prolactinomas is an important treatment for patients intolerant of dopamine agonist therapy. However, predictors of postoperative outcomes remain...
CONTEXT
Surgical management of prolactinomas is an important treatment for patients intolerant of dopamine agonist therapy. However, predictors of postoperative outcomes remain unclear.
OBJECT
While transsphenoidal surgical resection (TSSR) is important second-line therapy in prolactinoma patients, predictors of surgical cure and biochemical remission following TSSR remain sparse.
METHODS
A retrospective review of prolactinoma patients undergoing TSSR at the USC Pituitary Center from 1995 to 2020 was conducted. Participants were categorized as surgical cure (normalization of serum prolactin without medical treatment), surgical noncure, biochemical control (prolactin normalization with or without adjuvant therapy), and nonbiochemical control. A systematic review of the outcomes of surgically managed prolactinomas was performed.
RESULTS
The 40 female and 16 male participants had an average age of 35.6 years. Prior treatment included transsphenoidal resection (6, 11%) and dopamine agonist treatment (47, 84%). The 40 macroadenomas and 15 microadenomas exhibited suprasellar extension (24, 43%) and parasellar invasion (20, 36%). Fifteen (27%) were purely intrasellar. Gross total resection was achieved in 25 patients (45%) and subtotal in 26 (46%). Surgical cure was achieved in 25 patients (46%) and biochemical control in 35 (64%). Surgical cure was more likely in smaller, noninvasive tumors, those that were fully resected, and patients with lower preoperative (< 1000 ng/mL) and immediately postoperative (< 7.6 ng/mL) prolactin levels. Ten of 26 patients (38%) undergoing adjuvant therapy achieved biochemical control, which was less likely in men and those with higher preoperative prolactin or invasive tumors.
CONCLUSION
Surgical resection of prolactinomas is a safe procedure that, when offered judiciously, can achieve symptom and/or biochemical control in a majority of patients. A variety of predictors may be useful in advising patients on likelihood of postoperative remission.
PubMed: 34466765
DOI: 10.1210/jendso/bvab074 -
Neuroscience and Biobehavioral Reviews Mar 2023Cigarette smoking is often initiated during adolescence and an earlier age of onset is associated with worse health outcomes later in life. Paradoxically, the transition... (Review)
Review
Cigarette smoking is often initiated during adolescence and an earlier age of onset is associated with worse health outcomes later in life. Paradoxically, the transition towards adulthood also marks the potential for recovery, as the majority of adolescents are able to quit smoking when adulthood emerges. This systematic review aimed to evaluate the evidence from both human and animal studies for the differential impact of adolescent versus adult repeated and long-term tobacco and nicotine exposure on cognitive and brain outcomes. The limited human studies and more extensive yet heterogeneous animal studies, provide preliminary evidence of heightened fear learning, anxiety-related behaviour, reward processing, nicotinic acetylcholinergic receptors expression, dopamine expression and serotonin functioning after adolescent compared to adult exposure. Effects of nicotine or tobacco use on impulsivity were comparable across age groups. These findings provide novel insights into the mechanisms underlying adolescents' vulnerability to tobacco and nicotine. Future research is needed to translate animal to human findings, with a focus on directly linking a broader spectrum of brain and behavioural outcomes.
Topics: Animals; Humans; Adolescent; Adult; Nicotine; Tobacco Smoke Pollution; Nicotiana; Brain; Cognition
PubMed: 36627063
DOI: 10.1016/j.neubiorev.2023.105038 -
Drugs in R&D Mar 2023Dopamine antagonists are the main pharmacological options to treat gastroparesis. The aim of this study was to conduct a systematic literature review (SLR) to evaluate... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Dopamine antagonists are the main pharmacological options to treat gastroparesis. The aim of this study was to conduct a systematic literature review (SLR) to evaluate the profile of adverse events (AEs) of dopamine antagonists used in the treatment of children and adults with gastroparesis.
METHODS
We searched EMBASE and MEDLINE up to March 25, 2021, for relevant clinical trials and observational studies. We conducted a proportional meta-analysis to estimate the pooled occurrence of AEs (%), with 95% confidence interval (CI), from arm-level data across studies and the comparative occurrence of AEs from placebo-controlled clinical trials (odds ratio [OR] with 95% CI).
RESULTS
We identified 28 studies assessing AEs experienced by patients treated for gastroparesis with domperidone and metoclopramide; 22 studies contributed data to the meta-analyses. Cardiovascular, neurological, and endocrine AEs were commonly observed, with point incidences varying from 1 to > 50%. Clinically important AEs, such as QTc prolongation, occurred in 5% of patients treated with domperidone (95% CI: 3.32-8.62). Restlessness, an extrapyramidal AE, occurred in 15% of patients (95% CI: 7.48-26.61) treated with metoclopramide, with a 7-fold increase compared with patients receiving placebo (OR: 7.72; 95% CI: 1.27-47.05). Variation in terminology to describe extrapyramidal events precluded further pooled analyses. Additional meta-analyses were not feasible due to discrepancies in the assessment and reporting of the AEs.
CONCLUSIONS
The evidence confirms concerns of cardiovascular, extrapyramidal, and endocrine AEs in patients with gastroparesis treated with domperidone and metoclopramide. Imprecise AE reporting limits firm interpretation and conclusions.
REGISTRATION
PROSPERO international prospective register of systematic reviews (registration number: CRD42021248888).
Topics: Adult; Child; Humans; Domperidone; Metoclopramide; Gastroparesis; Dopamine Antagonists
PubMed: 36749528
DOI: 10.1007/s40268-023-00413-x -
Journal of Neurology, Neurosurgery, and... May 2022Neuropsychiatric symptoms are common in Parkinson's disease (PD) and predict poorer outcomes. Reward processing dysfunction is a candidate mechanism for the development... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Neuropsychiatric symptoms are common in Parkinson's disease (PD) and predict poorer outcomes. Reward processing dysfunction is a candidate mechanism for the development of psychiatric symptoms including depression and impulse control disorders (ICDs). We aimed to determine whether reward processing is impaired in PD and its relationship with neuropsychiatric syndromes and dopamine replacement therapy.
METHODS
The Ovid MEDLINE/PubMed, Embase and PsycInfo databases were searched for articles published up to 5 November 2020. Studies reporting reward processing task performance by patients with PD and healthy controls were included. Summary statistics comparing reward processing between groups were converted to standardised mean difference (SMD) scores and meta-analysed using a random effects model.
RESULTS
We identified 55 studies containing 2578 participants (1638 PD and 940 healthy controls). Studies assessing three subcomponent categories of reward processing tasks were included: option valuation (n=12), reinforcement learning (n=37) and reward response vigour (n=6). Across all studies, patients with PD on medication exhibited a small-to-medium impairment versus healthy controls (SMD=0.34; 95% CI 0.14 to 0.53), with greater impairments observed off dopaminergic medication in within-subjects designs (SMD=0.43, 95% CI 0.29 to 0.57). Within-subjects subcomponent analysis revealed impaired processing off medication on option valuation (SMD=0.57, 95% CI 0.39 to 0.75) and reward response vigour (SMD=0.36, 95% CI 0.13 to 0.59) tasks. However, the opposite applied for reinforcement learning, which relative to healthy controls was impaired on-medication (SMD=0.45, 95% CI 0.25 to 0.65) but not off-medication (SMD=0.28, 95% CI -0.03 to 0.59). ICD was the only neuropsychiatric syndrome with sufficient studies (n=13) for meta-analysis, but no significant impairment was identified compared tonon-ICD patients (SMD=-0.02, 95% CI -0.43 to 0.39).
CONCLUSION
Reward processing disruption in PD differs according to subcomponent and dopamine medication state, and warrants further study as a potential treatment target and mechanism underlying associated neuropsychiatric syndromes.
Topics: Disruptive, Impulse Control, and Conduct Disorders; Dopamine; Dopamine Agents; Humans; Parkinson Disease; Reward; Syndrome
PubMed: 34930778
DOI: 10.1136/jnnp-2021-327762 -
Frontiers in Endocrinology 2023Three dopamine agonists [bromocriptine, cabergoline, and quinagolide (CV)] have been used for hyperprolactinemia treatment for decades. Several studies have reviewed the... (Meta-Analysis)
Meta-Analysis
PURPOSE
Three dopamine agonists [bromocriptine, cabergoline, and quinagolide (CV)] have been used for hyperprolactinemia treatment for decades. Several studies have reviewed the efficacy and safety of bromocriptine and cabergoline. However, no systematic review or meta-analysis has discussed the efficacy and safety of CV in hyperprolactinemia and prolactinoma treatment.
METHODS
Five medical databases (PubMed, Web of Science, Embase, Scopus, and Cochrane Library) were searched up to 9 May 2022 to identify studies related to CV and hyperprolactinemia. A meta-analysis was implemented by using a forest plot, funnel plot, sensitivity analysis, meta-regression, and Egger's test software R 4.0 and STATA 12.
RESULTS
A total of 1,211 studies were retrieved from the five medical databases, and 33 studies consisting of 827 patients were finally included in the analysis. The pooled proportions of patients with prolactin concentration normalization and tumor reduction (>50%) under CV treatment were 69% and 20%, respectively, with 95% confidence intervals of 61%-76% and 15%-28%, respectively. The pooled proportion of adverse effects was 13%, with a 95% confidence interval of 11%-16%.
CONCLUSION
Our study showed that CV is not less effective than cabergoline and bromocriptine in treating hyperprolactinemia, and the side effects were not significant. Hence, this drug could be considered an alternative first-line or rescue treatment in treating hyperprolactinemia in the future.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022347750.
Topics: Humans; Bromocriptine; Cabergoline; Drug-Related Side Effects and Adverse Reactions; Hyperprolactinemia; Pituitary Neoplasms; Aminoquinolines
PubMed: 36761195
DOI: 10.3389/fendo.2023.1027905 -
Psychopharmacology Feb 2024Dopamine antagonists induce dopamine receptor supersensitivity. This may manifest in late-appearing movement disorders (tardive dyskinesia (TD). VMAT-2 inhibitors reduce... (Meta-Analysis)
Meta-Analysis Review
RATIONALE
Dopamine antagonists induce dopamine receptor supersensitivity. This may manifest in late-appearing movement disorders (tardive dyskinesia (TD). VMAT-2 inhibitors reduce dopaminergic transmission but have limited activity at postsynaptic receptors and so may have antipsychotic activity with lower risk of tardive dyskinesia.
METHODS
We conducted a systematic database search from inception to September 2022 for articles describing the use of VMAT-2 inhibitors in psychosis. Inclusion criteria were as follows: Population: adults diagnosed with psychosis or schizophrenia; Intervention: treatment with tetrabenazine, deutetrabenazine or valbenazine; Comparison: comparison with placebo or/and antipsychotic drug; Outcomes: with efficacy outcomes (e.g. Brief Psychiatric Rating Scale (BPRS) change or clinician assessment) and adverse effects ratings (e.g. rating scale or clinician assessment or dropouts); and Studies: in randomised controlled trials and non-randomised studies.
RESULTS
We identified 4892 records relating to VMAT-2 inhibitor use of which 5 (173 participants) met our a priori meta-analysis inclusion criteria. VMAT-2 inhibitors were more effective than placebo for the outcome 'slight improvement' (risk ratio (RR) = 1.77 (95% CI 1.03, 3.04)) but not for 'moderate improvement' (RR 2.81 (95% CI 0.27, 29.17). VMAT-2 inhibitors were as effective as active comparators on both measures for-'slight improvement' (RR 1.05 (95% CI 0.6, 1.81)) and 'moderate improvement' (RR 1.11 (95% CI 0.51, 2.42). Antipsychotic efficacy was also suggested by a narrative review of 37 studies excluded from the meta-analysis.
CONCLUSIONS
VMAT-2 inhibitors may have antipsychotic activity and may offer promise for treatment of psychosis with the potential for a reduced risk of TD.
Topics: Adult; Humans; Antipsychotic Agents; Psychotic Disorders; Schizophrenia; Tardive Dyskinesia; Tetrabenazine; Vesicular Monoamine Transport Proteins
PubMed: 38238580
DOI: 10.1007/s00213-023-06488-3 -
Movement Disorders : Official Journal... Aug 2021Dopamine receptors are abundant along the central nigrostriatal tract and are expressed as 5 subtypes in two receptor families. In PD, compensatory changes in dopamine... (Meta-Analysis)
Meta-Analysis Review
Dopamine receptors are abundant along the central nigrostriatal tract and are expressed as 5 subtypes in two receptor families. In PD, compensatory changes in dopamine receptors emerge as a consequence of the loss of dopamine nerve terminals or dopaminergic pharmacotherapy. We performed a systematic review and meta-analysis of the available PET and single-photon emission computed tomography studies that have investigated dopamine receptors in PD, PSP and MSA. The inclusion criteria were studies including human PET or single-photon emission computed tomography imaging; dopamine receptor tracers (D1-like or D2-like) and idiopathic PD, PSP, or MSA patients compared with healthy controls. The 67 included D2-like studies had 1925 patients. Data were insufficient for an analysis of D1-like studies. PD patients had higher striatal binding early in the disease, but after a disease duration of 4.36 years, PD patients had lower binding values than healthy controls. Striatal D2R binding was highest in unmedicated early PD patients and in the striatum contralateral to the predominant motor symptoms. PSP and MSA-P patients had lower striatal D2R binding than PD patients (14.2% and 21.8%, respectively). There is initial upregulation of striatal D2Rs in PD, which downregulate on average 4 years after motor symptom onset, possibly because of agonist-induced effects. The consistent upregulation of D2Rs in the PD striatum contralateral to the predominant motor symptoms indicates that receptor changes are driven by neurodegeneration and loss of striatal neuropil. Both PSP and MSA patients have clearly lower striatal D2R binding values than PD patients, which offers an opportunity for differential diagnostics. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Topics: Corpus Striatum; Dopamine; Dopamine Plasma Membrane Transport Proteins; Humans; Parkinson Disease; Receptors, Dopamine D2; Tomography, Emission-Computed, Single-Photon
PubMed: 33955044
DOI: 10.1002/mds.28632 -
Behavioral Sciences (Basel, Switzerland) Oct 2021Although blockade of dopamine receptors D2 and D3 appears to be the main mechanism of antipsychotic action, treatment response variability calls for an examination of... (Review)
Review
Dopamine, Serotonin, and Structure/Function Brain Defects as Biological Bases for Treatment Response in Delusional Disorder: A Systematic Review of Cases and Cohort Studies.
Although blockade of dopamine receptors D2 and D3 appears to be the main mechanism of antipsychotic action, treatment response variability calls for an examination of other biological systems. Our aim is to systematically review reports of treatment response in delusional disorder (DD) in order to help determine its biological bases. Computerized searches of ClinicalTrials.gov, PubMed, and Scopus databases (from 1999 to September 2021) were systematically reviewed, in keeping with PRISMA directives. We used the search terms: (treat * OR therap * AND (delusional disorder)). We included all studies that explored the biological mechanisms of treatment response in DD, as diagnosed by ICD or DSM criteria. A total of 4344 records were initially retrieved, from which 14 papers were included: case reports, case series, and cohort studies. Findings point to (1) dopaminergic dysfunction (based on biochemical and genetic studies), (2) serotonergic dysfunction (based on partial agonism/antagonism of drugs), and (3) brain structure/function impairment, especially in the temporal and parietal lobes, as crucial factors in treatment response. Further studies with higher levels of evidence are needed to help clinicians determine treatment.
PubMed: 34677234
DOI: 10.3390/bs11100141 -
Basic & Clinical Pharmacology &... Jan 2019The effect of risperidone treatment in patients with schizophrenia varies according to the dopamine receptor genes. This study aimed to evaluate the relationship between... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The effect of risperidone treatment in patients with schizophrenia varies according to the dopamine receptor genes. This study aimed to evaluate the relationship between genes of the dopamine receptors (D1, D2, and D3) and the effect of risperidone treatment.
METHODS
Three electronic databases (PubMed, Embase, and Cochrane Library) were searched for relevant cohort or case-control studies published before 9 May 2018. A systematic review and meta-analysis was performed for qualitative and quantitative assessment of the relationship between the dopamine receptors D1, D2, and D3 (DRD1, 2, and 3) and the effect of risperidone treatment. The summary odds ratio (OR) and weighted mean difference (WMD) in a random-effects model were used to measure these relationships.
RESULTS
Twelve studies involving 24 SNPs were included. DRD2 (Ser311Cys, rs1801028 Ser/Ser) significantly lowered the improvement rate (determined by the PANSS score) unlike Ser/Cys (WMD: -11.58, 95% CI: -17.35 to -5.18). For Asian patients, A241G (rs1799978) AA carriers showed greater improvement after risperidone therapy (P < 0.05). The polymorphisms of 141C Ins/Del (rs1799732), T939C (rs6275), rs6277, and TaqID (rs1800498) may also influence the treatment effect. TaqIA (rs1800497) and TaqIB (rs17294542) were not associated with the rate of response to risperidone. DRD3 was not associated with an improvement in the PANSS total score; however, Ser9Gly might be related to a change in negative symptoms. No significant effect of DRD1 (rs5326, rs4867798, rs4532, and rs11749676) was found.
CONCLUSIONS
Our result supported the hypothesis that DRD2 affected risperidone treatment. DRD1 had no significant effect on the response to risperidone, whereas DRD3 might be associated with an improvement in negative symptoms. Larger observational studies are warranted to verify these findings and identify other genetic factors involved.
Topics: Antipsychotic Agents; Humans; Pharmacogenomic Variants; Polymorphism, Single Nucleotide; Receptors, Dopamine D1; Receptors, Dopamine D2; Receptors, Dopamine D3; Risperidone; Schizophrenia; Treatment Outcome
PubMed: 30103286
DOI: 10.1111/bcpt.13111