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European Archives of Psychiatry and... Aug 2021The objective is to understand genetic predisposition to delirium. Following PRISMA guidelines, we undertook a systematic review of studies involving delirium and... (Meta-Analysis)
Meta-Analysis
The objective is to understand genetic predisposition to delirium. Following PRISMA guidelines, we undertook a systematic review of studies involving delirium and genetics in the databases of Pubmed, Scopus, Cochrane Library and PsycINFO, and performed a meta-analysis when appropriate. We evaluated 111 articles, of which 25 were finally included in the analysis. The studies were assessed by two independent researchers for methodological quality using the Downs and Black Tool and for genetic analysis quality. We performed a meta-analysis of 10 studies of the Apolipoprotein E (APOE) gene, obtaining no association with the presence of delirium (LOR 0.18, 95% CI - 0.10-0.47, p = 0.21). Notably, only 5 out of 25 articles met established criteria for genetic studies (good quality) and 6 were of moderate quality. Seven studies found an association with APOE4, the dopamine transporter gene SCL6A3, dopamine receptor 2 gene, glucocorticoid receptor, melatonin receptor and mitochondrial DNA haplotypes. One genome-wide association study found two suggestive long intergenic non-coding RNA genes. Five studies found no association with catechol-o-methyltransferase, melatonin receptor or several interleukins genes. The studies were heterogenous in establishing the presence of delirium. Future studies with large samples should further specify the delirium phenotype and deepen our understanding of interactions between genes and other biological factors.
Topics: Delirium; Genetic Predisposition to Disease; Humans
PubMed: 33779822
DOI: 10.1007/s00406-021-01255-x -
Journal of Diabetes and Metabolic... Dec 2023The Dopamine-2 receptor agonists, Bromocriptine and Cabergoline, were originally introduced for prolactinomas, pituitary tumors, and parkinson's disease but have... (Review)
Review
BACKGROUND
The Dopamine-2 receptor agonists, Bromocriptine and Cabergoline, were originally introduced for prolactinomas, pituitary tumors, and parkinson's disease but have glucose-lowering effects. This paper systematically reviewed the significance of their effects on lowering blood glucose level and conducted a comprehensive systematic search to identify relevant clinical trials of dopamine 2 agonists on glycated hemoglobin (HbA1c) and fasting blood sugar (FBS).
METHOD
We conducted a systematic review search in the databases (PubMed, Google Scholar, Cochrane Library, Registers, and Citations) until November 30, 2022, using the PRISMA 2020 statement. The Oxford quality score (Jadad score) was used to assess the study's quality. The present study protocol was registered on the PROSPERO database with ID: CRD42023389582. The study included studies with full abstracts, predefined doses, clear interventions, and blood glucose measurements.
RESULT
Data were synthesized from 23 clinical studies that recruited 6125 study subjects. The pooled effect analysis of the clinical trials revealed that dopamine 2 agonists improved HbA1c [SMD = -1.26; 95% CI (-1.60, -0.93), < .00001], and FBS [SMD = -1.84; 95% CI (-2.61, -1.07), < .00001]. Each drug's pooled effect analysis indicates bromocriptine significantly improved HbA1c [SMD = -1.25; 95% CI (-1.64, -0.87), < .00001] and FBS [SMD = -1.90; 95% CI (-2.79, -1.01), < .00001] and similarly, cabergoline significantly improved HbA1c [SMD = -1.29; 95% CI (-1.96, -0.62), < .00001] and FBS [SMD = -1.62; 95% CI (-2.82, -0.41), < .00001]. The pooled and individual analyses demonstrated that dopamine 2 agonists have a significant ability to lower blood glucose levels in clinical studies.
CONCLUSION
This study shows that dopamine 2 agonists significantly lowered FBS and HbA1c levels without causing severe negative effects. Even though the results are promising, additional research is necessary to establish the appropriate antihyperglycemic dosage, frequency of daily use, side effects, and potential product interactions when employing dopamine 2 receptor agonists for their antihyperglycemic effect.
PubMed: 37975084
DOI: 10.1007/s40200-023-01230-4 -
Expert Review of Clinical Pharmacology 2023Olanzapine is widely used for treating schizophrenia and bipolar I disorder. Due to its high pharmacokinetic variability, several population pharmacokinetic studies have... (Review)
Review
INTRODUCTION
Olanzapine is widely used for treating schizophrenia and bipolar I disorder. Due to its high pharmacokinetic variability, several population pharmacokinetic studies have been performed to identify factors contributing to the variability and thus facilitate individualized dosing. This review aims to provide a comprehensive overview of published population pharmacokinetic studies and explore potential covariates.
METHODS
We systematically searched PubMed, Web of Science, and EMBASE databases from their inception to 31 December 2022. Information on the study design, characteristics, and final parameter estimates was summarized and compared. Monte Carlo simulations provided visual predictive distributions to compare eligible studies. Forest plots were constructed to explore the effects of covariates on olanzapine pharmacokinetics.
RESULTS
A total of 10 population pharmacokinetic and three population pharmacokinetic/pharmacodynamic studies involving infants, children, adolescents, and adults were finally included. The median apparent clearance was 0.253 L/h/kg in adults, 27-43% lower than that of infants and children. Men and smokers increased the apparent clearance of olanzapine by 32% and 34%, respectively. The concentration required to achieve half of the maximum effect for the Positive and Negative Syndrome Scale total score was 24.80 ng/mL, comparable with 22.32 ng/mL for dopamine D receptor occupancy.
CONCLUSIONS
A higher dosage may be required for men or heavy smokers than for women or nonsmokers to reach the same exposure. Moreover, further population studies are essential to be conducted to clarify the dose-exposure-response relationship of olanzapine.
PROSPERO REGISTRATION
CRD42022368637.
Topics: Male; Adult; Child; Infant; Adolescent; Humans; Female; Olanzapine; Antipsychotic Agents; Schizophrenia; Research Design; Models, Biological
PubMed: 37231707
DOI: 10.1080/17512433.2023.2219055 -
Journal of Psychiatric Research Jun 2023An increasing number of studies have used positron emission tomography (PET) to investigate molecular neurobiological differences in individuals who use cannabis. This... (Review)
Review
BACKGROUND
An increasing number of studies have used positron emission tomography (PET) to investigate molecular neurobiological differences in individuals who use cannabis. This study aimed to systematically review PET imaging research in individuals who use cannabis or have cannabis use disorder (CUD).
METHODS
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria, a comprehensive systematic review was undertaken using the PubMed, Scopus, PsycINFO and Web of Science databases.
RESULTS
In total, 20 studies were identified and grouped into three themes: (1) studies of the dopamine system primarily found that cannabis use was associated with abnormal striatal dopamine synthesis capacity, which was in turn correlated with clinical symptoms; (2) studies of the endocannabinoid system found that cannabis use and CUD are associated with lower cannabinoid receptor type 1 availability and global reductions in fatty acid amide hydrolase binding; (3) studies of brain metabolism found that individuals who use cannabis exhibit lower normalized glucose metabolism in both cortical and subcortical brain regions, and reduced cerebral blood flow in the lateral prefrontal cortex during experimental tasks. Heterogeneity across studies prevented meta-analysis.
CONCLUSION
Existing PET imaging research reveals substantive molecular differences in cannabis users in the dopamine and endocannabinoid systems, and in global brain metabolism, although the heterogeneity of designs and approaches is very high, and whether these differences are causal versus consequential is largely unclear.
Topics: Humans; Cannabis; Endocannabinoids; Dopamine; Brain; Positron-Emission Tomography; Hallucinogens
PubMed: 37088043
DOI: 10.1016/j.jpsychires.2023.03.045 -
Frontiers in Aging Neuroscience 2019The dopaminergic system has been associated with the progression of Alzheimer's disease. But previous studies found inconsistent results regarding the relationship...
The dopaminergic system has been associated with the progression of Alzheimer's disease. But previous studies found inconsistent results regarding the relationship between Alzheimer's disease and dopamine when looking at dopamine receptor concentrations. The aim of this review was to synthesize, using a random-effects model of meta-analysis, the link between the dopaminergic system and Alzheimer's disease. A detailed analysis protocol was registered at the PROSPERO database prior to data extraction (CRD42018110798). Electronic databases of PubMed, Embase, Web of Science, and Psyc-ARTICLES were searched up to December 2018 for studies that examined dopamine and dopamine receptors in relation to Alzheimer's disease. Standardized mean differences (SMD) were calculated to assess group differences in the levels of dopaminergic neurometabolites. Seventeen studies met the eligibility criteria. Collectively, they included 512 patients and 500 healthy controls. There were significantly lower levels of dopamine in patients with Alzheimer's disease compared with controls (SMD = -1.56, 95% CI: -2.64 to -0.49). In addition, dopamine 1 receptor (SMD = -5.05, 95% CI: -6.14 to -3.97) and dopamine 2 receptor (SMD = -1.13, 95% CI: -1.52 to -0.74) levels were decreased in patients with Alzheimer's disease compared with controls. The results of network meta-analysis indicated that the rank of correlation with Alzheimer's disease from highest to lowest was dopamine (0.74), dopamine 2 receptor (0.49), dopamine 3 receptor (0.46), dopamine 4 receptor (0.33), dopamine 5 receptor (0.31), and dopamine 1 receptor (0.64). Overall, decreased levels of dopaminergic neurotransmitters were linked with the pathophysiology of Alzheimer's disease. Nonetheless, there is a clear need for more prospective studies to validate these hypotheses.
PubMed: 31354471
DOI: 10.3389/fnagi.2019.00175 -
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 -
Neuroscience and Biobehavioral Reviews Dec 2020Dopamine has a crucial and well-documented role in the development and maintenance of Gambling Disorder (GD). This systematic review adopts a translational approach... (Review)
Review
Dopamine has a crucial and well-documented role in the development and maintenance of Gambling Disorder (GD). This systematic review adopts a translational approach aimed at providing a comprehensive synthesis of current clinical and preclinical knowledge on dopaminergic function in GD at a neurobiological level. To this end, we present and discuss converging dopaminergic alterations and phenotypes. Preclinical and clinical review protocols were registered on the PROSPERO database (CRD42019124404, CRD42019124405). The literature search was conducted in accordance with PRISMA guidelines using three databases (PubMed, Web of Science, Scopus). We identified 67 preclinical studies using pharmacological and non-pharmacological manipulations of the gambling-like phenotype and 33 human studies investigating either genetic polymorphisms or functional brain imaging data. Dopamine transporter and D2, D3, D4 receptor alterations showed strongest translational concordance. Though no postsynaptic dopaminergic alterations were observed, several studies point at dysfunctions in presynaptic dopamine trafficking in GD, suggestive of hyperdopaminergic states. Developing meaningful translational models is essential to working towards the development of an integrated conceptual framework for GD and neurobiologically-based treatment interventions.
Topics: Dopamine; Gambling; Humans
PubMed: 33035523
DOI: 10.1016/j.neubiorev.2020.09.034 -
Pharmacological Research Jul 2022Cannabis sativa is a recreational drug commonly consumed in Europe and is getting popularity for both recreational and therapeutic use. In some individuals, the use of... (Review)
Review
OBJECTIVE
Cannabis sativa is a recreational drug commonly consumed in Europe and is getting popularity for both recreational and therapeutic use. In some individuals, the use of cannabis leads to psychotic disorders. This systematic review summarizes the current evidence linking genetic polymorphisms and inter-individual susceptibility to psychosis induced by cannabis.
METHOD
Studies published from 2005 to 2020 were identified through Medline using PubMed, Web of Science and Scopus database and searches were conducted according to PRISMA guidelines. Initial search was performed with terms: "cannabis induced psychosis" AND "genetics".
RESULTS
From the initial group of 108 papers, 18 studies met our inclusion criteria. Many of the findings revealed associations with genetic polymorphisms modulations of genes involved directly (COMT, DRD2 and DAT) or indirectly (AKT1) to dopamine pathways. The most consistent finding was with COMT rs4680, where the presence of the Val allele was associated with a higher risk for cannabis-induced psychosis. This higher susceptibility was also reported for AKT1 (rs2494732) with the CC genotype. Of note, the only genome-wide association study identified a significant signal close to the cholinergic receptor muscarinic 3 represented by rs115455482 and rs74722579 predisposing to cannabis-induced hallucinations and remarkably no dopaminergic target was found.
CONCLUSION
Actual evidence supports the role of dopamine in cannabis induced psychosis. However, most of genetic polymorphism studies have as a starting point the pre-existing dopaminergic theoretical basis for psychosis. This alerts to the importance of more broad genetic studies. Integrate genetic results into biological systems may enhance our knowledge of cannabis induced psychosis and could help in the prevention and treatment of these patients.
Topics: Cannabis; Catechol O-Methyltransferase; Dopamine; Genetic Predisposition to Disease; Genome-Wide Association Study; Humans; Marijuana Abuse; Polymorphism, Single Nucleotide; Psychotic Disorders
PubMed: 35588917
DOI: 10.1016/j.phrs.2022.106258 -
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 -
Healthcare (Basel, Switzerland) Apr 2023Temporal discounting is a phenomenon where a reward loses its value as a function of time (e.g., a reward is more valuable immediately than when it delays in time). This... (Review)
Review
Temporal discounting is a phenomenon where a reward loses its value as a function of time (e.g., a reward is more valuable immediately than when it delays in time). This is a type of intertemporal decision-making that has an association with impulsivity and self-control. Many pathologies exhibit higher discounting rates, meaning they discount more the values of rewards, such as addictive behaviors, bipolar disorder, attention-deficit/hyperactivity disorders, social anxiety disorders, and major depressive disorder, among others; thus, many studies look for the mechanism and neuromodulators of these decisions. This systematic review aims to investigate the association between pharmacological administration and changes in temporal discounting. A search was conducted in PubMed, Scopus, Web of Science, Science Direct and Cochrane. We used the PICO strategy: healthy humans (P-Participants) that received a pharmacological administration (I-Intervention) and the absence of a pharmacological administration or placebo (C-Comparison) to analyze the relationship between the pharmacological administration and the temporal discounting (O-outcome). Nineteen studies fulfilled the inclusion criteria. The most important findings were the involvement of dopamine modulation in a U-shape for choosing the delayed outcome (metoclopradime, haloperidol, and amisulpride). Furthermore, administration of tolcapone and high doses of d-amphetamine produced a preference for the delayed option. There was a time-dependent hydrocortisone effect in the preference for the immediate reward. Thus, it can be concluded that dopamine is a crucial modulator for temporal discounting, especially the D2 receptor, and cortisol also has an important time-dependent role in this type of decision. One of the limitations of this systematic review is the heterogeneity of the drugs used to assess the effect of temporal discounting.
PubMed: 37046974
DOI: 10.3390/healthcare11071046