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Frontiers in Neuroscience 2020The dopaminergic system is involved in many psychiatric disorders as a GABAergic, serotonergic, and glutamatergic system. A systematic review and meta-analysis was...
The dopaminergic system is involved in many psychiatric disorders as a GABAergic, serotonergic, and glutamatergic system. A systematic review and meta-analysis was performed to elucidate the alteration of the dopaminergic system in anxiety and compulsive disorders. The databases of Pubmed, Embase, and ScienceDirect were searched and articles reporting the involvement of the dopaminergic system in patients with anxiety disorder and obsessive compulsive disorder (OCD) were recognized. The key research data were extracted from the included articles and standardized mean differences were calculated using meta-analyses if there were more than two studies with obtainable data. Sensitivity analyses were further performed to detect the stability of results, and the qualities of all the included studies were assessed using the Newcastle Ottawa scale. Finally, we identified 8 and 11 studies associated with anxiety disorder and OCD for further analysis, respectively. Most consistently, the striatal dopamine D receptor (DR) of OCD patients had decreased while no significant correlation was found between striatal D2R and disease severity. The striatal dopamine transporter (DAT) had not been significantly altered in both the anxiety disorder and OCD patients. The heterogeneity values from the meta-analyses were extremely high while those results remained stable after sensitivity analyses. Inconsistent data were found in the striatal DR of patients with anxiety disorder. Limited data had suggested that dopamine synthesis increased in most regions of the cerebral cortex and cerebellum in OCD patients. The most convincing finding was that the D receptor decreased in patients with obsessive compulsive disorder. The dopamine transporter may have no relationship with anxiety and compulsive disorder.
PubMed: 33343291
DOI: 10.3389/fnins.2020.608520 -
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 -
The Cochrane Database of Systematic... Nov 2017Uterine fibroids occur in up to 40% of women aged over 35 years. Some are asymptomatic, but up to 50% cause symptoms that warrant therapy. Symptoms include anaemia... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Uterine fibroids occur in up to 40% of women aged over 35 years. Some are asymptomatic, but up to 50% cause symptoms that warrant therapy. Symptoms include anaemia caused by heavy menstrual bleeding, pelvic pain, dysmenorrhoea, infertility and low quality of life. Surgery is the first choice of treatment. In recent years, medical therapies have been used before surgery to improve intraoperative and postoperative outcomes. However, such therapies tend to be expensive.Fibroid growth is stimulated by oestrogen. Gonadotropin-hormone releasing analogues (GnRHa) induce a state of hypo-oestrogenism that shrinks fibroids , but has unacceptable side effects if used long-term. Other potential hormonal treatments, include progestins and selective progesterone-receptor modulators (SPRMs).This is an update of a Cochrane Review published in 2000 and 2001; the scope has been broadened to include all preoperative medical treatments.
OBJECTIVES
To assess the effectiveness and safety of medical treatments prior to surgery for uterine fibroids.
SEARCH METHODS
We searched the Cochrane Gynaecology and Fertility Group specialised register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL in June 2017. We also searched trials registers (ClinicalTrials.com; WHO ICTRP), theses and dissertations and the grey literature, handsearched reference lists of retrieved articles and contacted pharmaceutical companies for additional trials.
SELECTION CRITERIA
We included randomised comparisons of medical therapy versus placebo, no treatment, or other medical therapy before surgery, myomectomy, hysterectomy or endometrial resection, for uterine fibroids.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by The Cochrane Collaboration.
MAIN RESULTS
We included a total of 38 RCTs (3623 women); 19 studies compared GnRHa to no pretreatment (n = 19), placebo (n = 8), other medical pretreatments (progestin, SPRMs, selective oestrogen receptor modulators (SERMs), dopamine agonists, oestrogen receptor antagonists) (n = 7), and four compared SPRMs with placebo. Most results provided low-quality evidence due to limitations in study design (poor reporting of randomisation procedures, lack of blinding), imprecision and inconsistency. GnRHa versus no treatment or placebo GnRHa treatments were associated with reductions in both uterine (MD -175 mL, 95% CI -219.0 to -131.7; 13 studies; 858 participants; I² = 67%; low-quality evidence) and fibroid volume (heterogeneous studies, MD 5.7 mL to 155.4 mL), and increased preoperative haemoglobin (MD 0.88 g/dL, 95% CI 0.7 to 1.1; 10 studies; 834 participants; I² = 0%; moderate-quality evidence), at the expense of a greater likelihood of adverse events, particularly hot flushes (OR 7.68, 95% CI 4.6 to 13.0; 6 studies; 877 participants; I² = 46%; moderate-quality evidence).Duration of hysterectomy surgery was reduced among women who received GnRHa treatment (-9.59 minutes, 95% CI 15.9 to -3.28; 6 studies; 617 participants; I² = 57%; low-quality evidence) and there was less blood loss (heterogeneous studies, MD 25 mL to 148 mL), fewer blood transfusions (OR 0.54, 95% CI 0.3 to 1.0; 6 studies; 601 participants; I² = 0%; moderate-quality evidence), and fewer postoperative complications (OR 0.54, 95% CI 0.3 to 0.9; 7 studies; 772 participants; I² = 28%; low-quality evidence).GnRHa appeared to reduce intraoperative blood loss during myomectomy (MD 22 mL to 157 mL). There was no clear evidence of a difference among groups for other primary outcomes after myomectomy: duration of surgery (studies too heterogeneous for pooling), blood transfusions (OR 0.85, 95% CI 0.3 to 2.8; 4 studies; 121 participants; I² = 0%; low-quality evidence) or postoperative complications (OR 1.07, 95% CI 0.43 to 2.64; I² = 0%; 5 studies; 190 participants; low-quality evidence). No suitable data were available for analysis of preoperative bleeding. GnRHa versus other medical therapies GnRHa was associated with a greater reduction in uterine volume (-47% with GnRHa compared to -20% and -22% with 5 mg and 10 mg ulipristal acetate) but was more likely to cause hot flushes (OR 12.3, 95% CI 4.04 to 37.48; 5 studies; 183 participants; I² = 61%; low-quality evidence) compared with ulipristal acetate. There was no clear evidence of a difference in bleeding reduction (ulipristal acetate 5 mg: OR 0.71, 95% CI 0.3 to 1.7; 1 study; 199 participants; moderate-quality evidence; ulipristal acetate 10 mg: OR 0.39, 95% CI 0.1 to 1.1; 1 study; 203 participants; moderate-quality evidence) or haemoglobin levels (MD -0.2, 95% CI -0.6 to 0.2; 188 participants; moderate-quality evidence).There was no clear evidence of a difference in fibroid volume between GnRHa and cabergoline (MD 12.71 mL, 95% CI -5.9 to 31.3; 2 studies; 110 participants; I² = 0%; low-quality evidence).The included studies did not report usable data for any other primary outcomes. SPRMs versus placebo SPRMs (mifepristone, CDB-2914, ulipristal acetate and asoprisnil) were associated with greater reductions in uterine or fibroid volume than placebo (studies too heterogeneous to pool) and increased preoperative haemoglobin levels (MD 0.93 g/dL, 0.5 to 1.4; 2 studies; 173 participants; I² = 0%; high-quality evidence). Ulipristal acetate and asoprisnil were also associated with greater reductions in bleeding before surgery (ulipristal acetate 5 mg: OR 41.41, 95% CI 15.3 to 112.4; 1 study; 143 participants; low-quality evidence; ulipristal acetate 10 mg: OR 78.83, 95% CI 24.0 to 258.7; 1 study; 146 participants; low-quality evidence; asoprisnil: MD -166.9 mL; 95% CI -277.6 to -56.2; 1 study; 22 participants; low-quality evidence). There was no evidence of differences in preoperative complications. No other primary outcomes were measured.
AUTHORS' CONCLUSIONS
A rationale for the use of preoperative medical therapy before surgery for fibroids is to make surgery easier. There is clear evidence that preoperative GnRHa reduces uterine and fibroid volume, and increases preoperative haemoglobin levels, although GnRHa increases the incidence of hot flushes. During hysterectomy, blood loss, operation time and complication rates were also reduced. Evidence suggests that ulipristal acetate may offer similar advantages (reduced fibroid volume and fibroid-related bleeding and increased haemoglobin levels) although replication of these studies is advised before firm conclusions can be made. Future research should focus on cost-effectiveness and distinguish between groups of women with fibroids who would most benefit.
Topics: Antineoplastic Agents, Hormonal; Blood Loss, Surgical; Chemotherapy, Adjuvant; Dopamine Agonists; Estrogen Antagonists; Female; Gonadotropin-Releasing Hormone; Humans; Hysterectomy; Leiomyoma; Myometrium; Operative Time; Preoperative Care; Progestins; Randomized Controlled Trials as Topic; Uterine Neoplasms
PubMed: 29139105
DOI: 10.1002/14651858.CD000547.pub2 -
International Journal of Molecular... Nov 2021an increased prevalence of gastro-duodenal ulceration was described almost sixty years ago as prodromal to idiopathic Parkinson's disease, while duodenal ulcers have...
BACKGROUND
an increased prevalence of gastro-duodenal ulceration was described almost sixty years ago as prodromal to idiopathic Parkinson's disease, while duodenal ulcers have been rarely diagnosed in patients with schizophrenia. The cytoprotective role of dopamine in animal models of gastrointestinal ulcerations has also been described. Interestingly, Parkinson's disease (PD) might share common pathophysiological links with inflammatory bowel disease (IBD) as epidemiological and genetic links already suggest. Thus, the aim of our study was to review the existing literature on the role of the gastrointestinal dopaminergic system in IBD pathogenesis and progression.
METHODS
a systematic search was conducted according to the PRISMA methodology.
RESULTS
twenty-four studies satisfied the predetermined criteria and were included in our qualitative analysis. Due to different observations (cross-sectional studies) as well as experimental setups and applied methodologies (in vivo and in vitro studies) a meta-analysis could not be performed. No ongoing clinical trials with dopaminergic compounds in IBD patients were found.
CONCLUSIONS
the impairment of the dopaminergic system seems to be a significant, yet underestimated, feature of IBD, and more in-depth observational studies are needed to further support the existing preclinical data.
Topics: Animals; Dopamine; Gastrointestinal Tract; Humans; Inflammatory Bowel Diseases
PubMed: 34884737
DOI: 10.3390/ijms222312932 -
JAMA Psychiatry May 2017Stimulant use disorder is common, affecting between 0.3% and 1.1% of the population, and costs more than $85 billion per year globally. There are no licensed treatments... (Meta-Analysis)
Meta-Analysis Review
IMPORTANCE
Stimulant use disorder is common, affecting between 0.3% and 1.1% of the population, and costs more than $85 billion per year globally. There are no licensed treatments to date. Several lines of evidence implicate the dopamine system in the pathogenesis of substance use disorder. Therefore, understanding the nature of dopamine dysfunction seen in stimulant users has the potential to aid the development of new therapeutics.
OBJECTIVE
To comprehensively review the in vivo imaging evidence for dopaminergic alterations in stimulant (cocaine, amphetamine, or methamphetamine) abuse or dependence.
DATA SOURCES
The entire PubMed, EMBASE, and PsycINFO databases were searched for studies from inception date to May 14, 2016.
STUDY SELECTION
Case-control studies were identified that compared dopaminergic measures between stimulant users and healthy controls using positron emission tomography or single-photon emission computed tomography to measure striatal dopamine synthesis or release or to assess dopamine transporter availability or dopamine receptor availability.
DATA EXTRACTION AND SYNTHESIS
Demographic, clinical, and imaging measures were extracted from each study, and meta-analyses and sensitivity analyses were conducted for stimulants combined, as well as for cocaine and for amphetamine and methamphetamine separately if there were sufficient studies.
MAIN OUTCOMES AND MEASURES
Differences were measured in dopamine release (assessed using change in the D2/D3 receptor availability after administration of amphetamine or methylphenidate), dopamine transporter availability, and dopamine receptor availability in cocaine users, amphetamine and methamphetamine users, and healthy controls.
RESULTS
A total of 31 studies that compared dopaminergic measures between 519 stimulant users and 512 healthy controls were included in the final analysis. In most of the studies, the duration of abstinence varied from 5 days to 3 weeks. There was a significant decrease in striatal dopamine release in stimulant users compared with healthy controls: the effect size was -0.84 (95% CI, -1.08 to -0.60; P < .001) for stimulants combined and -0.87 (95% CI, -1.15 to -0.60; P < .001) for cocaine. In addition, there was a significant decrease in dopamine transporter availability: the effect size was -0.91 (95% CI, -1.50 to -0.32; P < .01) for stimulants combined and -1.47 (95% CI, -1.83 to -1.10; P < .001) for amphetamine and methamphetamine. There was also a significant decrease in D2/D3 receptor availability: the effect size was -0.76 (95% CI, -0.92 to -0.60; P < .001) for stimulants combined, -0.73 (95% CI, -0.94 to -0.53; P < .001) for cocaine, and -0.81 (95% CI, -1.12 to -0.49; P < .001) for amphetamine and methamphetamine. Consistent alterations were not found in vesicular monoamine transporter, dopamine synthesis, or D1 receptor studies.
CONCLUSIONS AND RELEVANCE
Data suggest that both presynaptic and postsynaptic aspects of the dopamine system in the striatum are down-regulated in stimulant users. The commonality and differences between these findings and the discrepancies with the preclinical literature and models of drug addiction are discussed, as well as their implications for future drug development.
Topics: Amphetamine-Related Disorders; Cocaine-Related Disorders; Corpus Striatum; Dopamine; Dopamine Plasma Membrane Transport Proteins; Humans; Receptors, Dopamine
PubMed: 28297025
DOI: 10.1001/jamapsychiatry.2017.0135 -
Frontiers in Psychiatry 2023Alcohol use disorder (AUD) is often described as repeated phases of binge drinking, compulsive alcohol-taking, craving for alcohol during withdrawal, and drinking with...
Alcohol use disorder (AUD) is often described as repeated phases of binge drinking, compulsive alcohol-taking, craving for alcohol during withdrawal, and drinking with an aim to a reduce the negative consequences. Although multifaceted, alcohol-induced reward is one aspect influencing the former three of these. The neurobiological mechanisms regulating AUD processes are complex and one of these systems is the gut-brain peptide ghrelin. The vast physiological properties of ghrelin are mediated growth hormone secretagogue receptor (GHSR, ghrelin receptor). Ghrelin is well known for its ability to control feeding, hunger, and metabolism. Moreover, ghrelin signaling appears central for alcohol-mediated responses; findings reviewed herein. In male rodents GHSR antagonism reduces alcohol consumption, prevents relapse drinking, and attenuates the motivation to consume alcohol. On the other hand, ghrelin increases the consumption of alcohol. This ghrelin-alcohol interaction is also verified to some extent in humans with high alcohol consumption. In addition, either pharmacological or genetic suppression of GHSR decreases several alcohol-related effects (behavioral or neurochemical). Indeed, this suppression blocks the alcohol-induced hyperlocomotion and dopamine release in nucleus accumbens as well as ablates the alcohol reward in the conditioned place preference model. Although not fully elucidated, this interaction appears to involve areas central for reward, such as the ventral tegmental area (VTA) and brain nodes targeted by VTA projections. As reviewed briefly, the ghrelin pathway does not only modulate alcohol-mediated effects, it regulates reward-related behaviors induced by addictive drugs. Although personality traits like impulsivity and risk-taking behaviors are common in patients with AUD, the role of the ghrelin pathway thereof is unknown and remains to be studied. In summary, the ghrelin pathway regulates addiction processes like AUD and therefore the possibility that GHSR antagonism reduces alcohol or drug-taking should be explored in randomized clinical trials.
PubMed: 36970276
DOI: 10.3389/fpsyt.2023.1050973 -
Progress in Neurobiology Jun 2022Alterations of the dopaminergic system may be important neurobiological correlates of vulnerability and transition to psychosis. We systematically reviewed the evidence... (Review)
Review
Alterations of the dopaminergic system may be important neurobiological correlates of vulnerability and transition to psychosis. We systematically reviewed the evidence for dopaminergic alterations demonstrated by in-vivo imaging studies in humans at increased risk of developing psychosis, covering clinical, genetic, and environmental high-risk groups. All 63 included studies utilized Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), or neuromelanin-sensitive Magnetic Resonance Imaging (NM-MRI) methods to collect data concerning the dopaminergic system during rest and/or following pharmacological, behavioural, or cognitive challenges. The current evidence highlights that 1) striatal dopamine D receptor availability is unaltered in all three high-risk groups compared with healthy individuals; 2) striatal dopamine synthesis capacity (sDSC) is increased in some clinical and genetic high-risk individuals relative to controls (e.g. people that meet clinical criteria for being at ultra-high risk of developing psychosis and individuals with 22q11.2 deletion syndrome), while sDSC is decreased in cannabis-using environmental high-risk individuals. It seems likely that all three high-risk groups can be stratified into multiple subgroups, with varying risks to develop psychosis, transition rates, and underlying neurobiology. The present results support the hypothesis that dopaminergic abnormalities occur before high-risk individuals develop psychosis.
Topics: Corpus Striatum; Dopamine; Humans; Positron-Emission Tomography; Psychotic Disorders; Tomography, Emission-Computed, Single-Photon
PubMed: 35351599
DOI: 10.1016/j.pneurobio.2022.102265 -
Frontiers in Neurology 2018Around 30% Parkinson's disease (PD) patients develop impulse control disorders (ICDs) to D dopamine agonists and, to a lesser extent, levodopa. We aim to investigate...
Around 30% Parkinson's disease (PD) patients develop impulse control disorders (ICDs) to D dopamine agonists and, to a lesser extent, levodopa. We aim to investigate striatal dopaminergic function in PD patients with and without ICD. PubMed, Science Direct, EBSCO, and ISI Web of Science databases were searched (from inception to March 7, 2018) to identify PET or SPECT studies reporting striatal dopaminergic function in PD patients with ICD (ICD+) compared to those without ICD (ICD-). Studies which included drug naïve patients, explored non-pharmacological procedures (e.g., deep brain stimulation), and those using brain blood perfusion or non-dopaminergic markers were excluded. Standardized mean difference (SDM) was used and random-effect models were applied. Separate meta-analyses were performed for dopamine transporter level, dopamine release, and dopamine receptors availability in the putamen, caudate, dorsal, and ventral striatum. A total of 238 studies were title and abstract screened, of which 19 full-texts were assessed. Nine studies (ICD+: = 117; ICD-: = 175 patients) were included in the analysis. ICD+ showed a significant reduction of dopamine transporter binding in the putamen (SDM = -0.46; 95% CI: -0.80, -0.11; = 2.61; = 0.009), caudate (SDM = -0.38; 95% CI: -0.73, -0.04; = 2.18; = 0.03) and dorsal striatum (SDM = -0.45; 95% CI: -0.77, -0.13; = 2.76; = 0.006), and increased dopamine release to reward-related stimuli/gambling tasks in the ventral striatum (SDM = -1.04; 95% CI: -1.73, -0.35; = 2.95; = 0.003). Dopamine receptors availability did not differ between groups. Heterogeneity was low for dopamine transporter in the dorsal striatum ( = 0%), putamen ( = 0%) and caudate ( = 0%), and pre-synaptic dopamine release in the dorsal ( = 0%) and ventral striatum ( = 0%); heterogeneity was high for dopamine transporter levels in the ventral striatum ( = 80%), and for dopamine receptors availability in the ventral ( = 89%) and dorsal ( = 86%) striatum, putamen ( = 93%), and caudate ( = 71%). ICD+ patients show lower dopaminergic transporter levels in the dorsal striatum and increased dopamine release in the ventral striatum when engaged in reward-related stimuli/gambling tasks. This dopaminergic imbalance might represent a biological substrate for ICD in PD. Adequately powered longitudinal studies with drug naïve patients are needed to understand whether these changes may represent biomarkers of premorbid vulnerability to ICD.
PubMed: 30568628
DOI: 10.3389/fneur.2018.01018 -
JAMA Network Open Nov 2019The association between the D2 dopamine receptor gene (DRD2) Taq1A locus (rs1800497) and alcohol use disorder (AUD) is enduring but the subject of long-standing... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
The association between the D2 dopamine receptor gene (DRD2) Taq1A locus (rs1800497) and alcohol use disorder (AUD) is enduring but the subject of long-standing controversy; meta-analysis of studies across 3 decades shows an association between rs1800497 and AUD, but genome-wide analyses have detected no role for rs1800497 in any phenotype. No evidence has emerged that rs1800497, which is located in ANKK1, perturbs the expression or function of DRD2.
OBJECTIVE
To resolve contradictions in previous studies by identifying hidden confounders and assaying for functional effects of rs1800497 and other loci in the DRD2 region.
DATA SOURCES
PubMed (882 studies), Embase (1056 studies), and Web of Science (501 studies) databases were searched through August 2018. Three clinical populations-Finnish, Native American, and African American participants-were genotyped for 208 to 277 informative single-nucleotide polymorphisms (SNPs) across the DRD2 region to test the associations of SNPs in this region with AUD.
STUDY SELECTION
Eligible studies had diagnosis of AUD made by accepted criteria, reliable genotyping methods, sufficient genotype data to calculate odds ratios and 95% CIs, and availability of control allele frequencies or genotype frequencies.
DATA EXTRACTION AND SYNTHESIS
After meta-analysis of 62 studies, metaregression was performed to detect between-study heterogeneity and to explore the effects of moderators, including deviations of cases and controls from allele frequencies in large population databases (ExAC and 1000 Genomes). Linkage to AUD and the effect on gene expression of rs1800497 were evaluated in the context of other SNPs in the DRD2 region. Data analysis was performed from August 2018 to March 2019. This study follows the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline.
MAIN OUTCOMES AND MEASURES
The effects of rs1800497 and other SNPs in the DRD2 region on gene expression were measured in human postmortem brain samples via differential allelic expression and evaluated in other tissues via publicly available expression quantitative locus data.
RESULTS
A total of 62 studies of DRD2 and AUD with 16 294 participants were meta-analyzed. The rs1800497 SNP was associated with AUD (odds ratio, 1.23; 95% CI, 1.14-1.31; P < .001). However, the association was attributable to spuriously low allele frequencies in controls in positive studies, which also accounted for some between-study heterogeneity (I2 = 43%; 95% CI, 23%-58%; Q61 = 107.20). Differential allelic expression of human postmortem brain and analysis of expression quantitative loci in public data revealed that a cis-acting locus or loci perturb the DRD2 transcript level; however, rs1800497 does not and is not in strong disequilibrium with such a locus. Across the DRD2 region, other SNPs are more strongly associated with AUD than rs1800497, although no DRD2 SNP was significantly associated in these 3 clinical samples.
CONCLUSIONS AND RELEVANCE
In this meta-analysis, the significant association of DRD2 with AUD was reassessed. The DRD2 association was attributable to anomalously low control allele frequencies, not function, in positive studies. For genetic studies, statistical replication is not verification.
Topics: Alcoholism; Case-Control Studies; Female; Gene Frequency; Genome-Wide Association Study; Humans; Male; Middle Aged; Receptors, Dopamine D2
PubMed: 31702801
DOI: 10.1001/jamanetworkopen.2019.14940 -
International Journal of Molecular... Jul 2021Parkinson's disease (PD) is the second most frequent neurodegenerative disease, which creates a significant public health burden. There is a challenge for the...
BACKGROUND
Parkinson's disease (PD) is the second most frequent neurodegenerative disease, which creates a significant public health burden. There is a challenge for the optimization of therapies since patients not only respond differently to current treatment options but also develop different side effects to the treatment. Genetic variability in the human genome can serve as a biomarker for the metabolism, availability of drugs and stratification of patients for suitable therapies. The goal of this systematic review is to assess the current evidence for the clinical translation of pharmacogenomics in the personalization of treatment for Parkinson's disease.
METHODS
We performed a systematic search of Medline database for publications covering the topic of pharmacogenomics and genotype specific mutations in Parkinson's disease treatment, along with a manual search, and finally included a total of 116 publications in the review.
RESULTS
We analyzed 75 studies and 41 reviews published up to December of 2020. Most research is focused on levodopa pharmacogenomic properties and catechol-O-methyltransferase (COMT) enzymatic pathway polymorphisms, which have potential for clinical implementation due to changes in treatment response and side-effects. Likewise, there is some consistent evidence in the heritability of impulse control disorder via Opioid Receptor Kappa 1 (OPRK1), 5-Hydroxytryptamine Receptor 2A (HTR2a) and Dopa decarboxylase (DDC) genotypes, and hyperhomocysteinemia via the Methylenetetrahydrofolate reductase (MTHFR) gene. On the other hand, many available studies vary in design and methodology and lack in sample size, leading to inconsistent findings.
CONCLUSIONS
This systematic review demonstrated that the evidence for implementation of pharmacogenomics in clinical practice is still lacking and that further research needs to be done to enable a more personalized approach to therapy for each patient.
Topics: Antiparkinson Agents; Catechol O-Methyltransferase; Catechol O-Methyltransferase Inhibitors; Dopamine Agonists; Genotype; Humans; Levodopa; Monoamine Oxidase Inhibitors; Parkinson Disease; Pharmacogenetics; Pharmacogenomic Variants; Translational Research, Biomedical
PubMed: 34281267
DOI: 10.3390/ijms22137213