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Neurosurgical Focus Feb 2023Despite its relatively low prevalence, schizophrenia has a high burden of illness due to its lifelong effects and the fact that it is often refractory to psychotropic...
OBJECTIVE
Despite its relatively low prevalence, schizophrenia has a high burden of illness due to its lifelong effects and the fact that it is often refractory to psychotropic treatment. This review investigated how neurosurgical interventions, primarily neuromodulation through deep brain stimulation (DBS), can mitigate treatment-refractory schizophrenia. Pathophysiological data and ongoing clinical trials were reviewed to suggest which targets hold promise for neurosurgical efficacy.
METHODS
A systematic review of the literature was conducted via an electronic search of the PubMed, Scopus, and Web of Science databases. Included papers were human or animal studies of neurosurgical interventions for schizophrenia conducted between 2012 and 2022. An electronic search of ClinicalTrials.gov and the International Clinical Trials Registry Platform was conducted to find ongoing clinical trials. The ROBINS-I (Risk of Bias in Nonrandomized Studies of Interventions) assessment tool was used to evaluate risk of bias in the study.
RESULTS
Eight human and 2 rat studies were included in the review. Of the human studies, 5 used DBS targeting the nucleus accumbens, subgenual anterior cingulate cortex, habenula, and substantial nigra pars reticulata. The remaining 3 human studies reported the results of subcaudate tractotomies and anterior capsulotomies. The rat studies investigated DBS of the nucleus accumbens and medial prefrontal cortex. Overall, human studies demonstrated long-term reduction in Positive and Negative Syndrome Scale scores in many participants, with a low incidence of surgical and psychological side effects. The rat studies demonstrated improved prepulse and latent inhibition in the targeted areas after DBS.
CONCLUSIONS
As identified in this review, recent studies have investigated the potential effects of therapeutic DBS for schizophrenia, with varying results. DBS targets that have been explored include the hippocampus, subgenual anterior cingulate cortex, habenula, substantia nigra pars reticulata, and medial prefrontal cortex. In addition to DBS, other neuromodulatory techniques such as neuroablation have been studied. Current evidence suggests that neuroablation in the subcaudate tract and anterior capsulotomy may be beneficial for some patients. The authors recommend further exploration of neuromodulation for treatment-refractory schizophrenia, under the condition that rigorous standards be upheld when considering surgical candidacy for these treatments, given that their safety and efficacy remain to be determined.
Topics: Humans; Rats; Animals; Schizophrenia; Neurosurgery; Neurosurgical Procedures; Psychosurgery; Nucleus Accumbens; Deep Brain Stimulation
PubMed: 36724524
DOI: 10.3171/2022.11.FOCUS22620 -
Brain Sciences Jun 2021Physical activity (PA) may influence the secretion of neurotransmitters and thereby have positive consequences for an individual's vulnerability (i.e., reducing anxiety... (Review)
Review
Physical activity (PA) may influence the secretion of neurotransmitters and thereby have positive consequences for an individual's vulnerability (i.e., reducing anxiety and depressive symptoms). This systematic review aims to analyse the potential bidirectional effects of exercise on dopamine from young adulthood to old age. The article search was conducted in PubMed, Scopus, and Web of Science in December 2020. The inclusion criteria were longitudinal and experimental study design; outcomes included dopamine and exercise; effect of exercise on dopamine and vice versa; adults; and articles published in English, Portuguese, or Spanish. Fifteen articles were included in the review. We observed robust findings concerning the potential effects of PA on dopamine, which notably seem to be observable across a wide range of participants characteristics (including age and sex), a variety of PA characteristics, and a broad set of methods to analyse dopamine. By contrast, regarding the potential effects of dopamine on PA, findings were mixed across studies. Thus, there are robust effects of physical exercise on dopamine. These findings further strengthen the idea that innovative approaches could include PA interventions for treating and preventing mental disorders. Therefore, it seems that PA is a potential alternative to deal with mental health issues.
PubMed: 34201523
DOI: 10.3390/brainsci11070829 -
Phytomedicine : International Journal... Nov 2023Verbascoside is a natural and water-soluble phenylethanoid glycoside found in several medicinal plants. It has extensive pharmacological effects, including antioxidative... (Review)
Review
BACKGROUND
Verbascoside is a natural and water-soluble phenylethanoid glycoside found in several medicinal plants. It has extensive pharmacological effects, including antioxidative and antineoplastic actions, and a wide range of therapeutic effects against depression.
PURPOSE
In this review, we appraised preclinical and limited clinical evidence to fully discuss the anti-depression capacity of verbascoside and its holistic characteristics that can contribute to better management of depression in vivo and in vitro models, as well as, its toxicities and medicinal value.
METHODS
This review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A systematic review of 32 preclinical trials published up to April 2023, combined with a comprehensive bioinformatics analysis of network pharmacology and molecular docking, was conducted to elucidate the antidepressant mechanism of action of verbascoside. Studies included in the systematic review were obtained from 7 electronic databases: PubMed, Scopus, Web of Science, Cochrane, ResearchGate, ScienceDirect, and Google Scholar.
RESULTS
Studies on the antidepressant effects of verbascoside showed that various pharmacological mechanisms and pathways, such as modulating the levels of monoamine neurotransmitters, inhibiting hypothalamic-pituitary-adrenal (HPA) axis hyperfunction and promoting neuroprotection may be involved in the process of its action against depression. Verbascoside promotes dopamine (DA) biosynthesis by promoting the expression of tyrosine hydroxylase mRNA and protein, upregulates the expression of 5-hydroxytryptamine receptor 1B (5-HT1B), prominence protein, microtubule-associated protein 2 (MAP2), hemeoxygenase-1 (HO-1), SQSTM1, Recombinant Autophagy Related Protein 5 (ATG5) and Beclin-1, and decreases the expression of caspase-3 and a-synuclein, thus exerting antidepressant effects. We identified seven targets (CCL2, FOS, GABARAPL1, CA9, TYR, CA12, and SQSTM1) and three signaling pathways (glutathione metabolism, metabolism of xenobiotics by cytochrome P450, fluid shear stress and atherosclerosis) as potential molecular biological sites for verbascoside.
CONCLUSIONS
These findings provide strong evidence that verbascoside exerts its antidepressant effects through various pharmacological mechanisms. However, further multicentre clinical case-control and molecularly targeted fishing studies are required to confirm the clinical efficacy of verbascoside and its underlying direct targets.
Topics: Glycosides; Molecular Docking Simulation; Neuroprotection; Sequestosome-1 Protein
PubMed: 37657207
DOI: 10.1016/j.phymed.2023.155027 -
Journal of Psychopharmacology (Oxford,... Jan 2016Our brains are highly responsive to novelty. However, how novelty is processed in the brain, and what neurotransmitter systems play a role therein, remains elusive.... (Review)
Review
Our brains are highly responsive to novelty. However, how novelty is processed in the brain, and what neurotransmitter systems play a role therein, remains elusive. Here, we systematically review studies on human participants that have looked at the neuromodulatory basis of novelty detection and processing. While theoretical models and studies on nonhuman animals have pointed to a role of the dopaminergic, cholinergic, noradrenergic and serotonergic systems, the human literature has focused almost exclusively on the first two. Dopamine was found to affect electrophysiological responses to novelty early in time after stimulus presentation, but evidence on its effects on later processing was found to be contradictory: While neuropharmacological studies mostly yielded null effects, gene studies did point to an important role for dopamine. Acetylcholine seems to dampen novelty signals in the medial temporal lobe, but boost them in frontal cortex. Findings on 5-HT (serotonin) were found to be mostly contradictory. Two large gaps were identified in the literature. First, few studies have looked at neuromodulatory influences on behavioral effects of novelty. Second, no study has looked at the involvement of the noradrenergic system in novelty processing.
Topics: Animals; Brain; Electrophysiological Phenomena; Exploratory Behavior; Humans; Models, Theoretical; Neurotransmitter Agents
PubMed: 26601905
DOI: 10.1177/0269881115612238 -
Molecular Psychiatry Jul 2021Many epidemiological studies have highlighted the link between vitamin D deficiency and schizophrenia. In particular, two prominent studies report an association between... (Meta-Analysis)
Meta-Analysis Review
Many epidemiological studies have highlighted the link between vitamin D deficiency and schizophrenia. In particular, two prominent studies report an association between neonatal vitamin D deficiency and an increased risk of schizophrenia. In parallel, much has been learnt about the role of vitamin D in the developing central nervous system over the last two decades. Studies in rodent models of developmental vitamin D (DVD)-deficiency describe how brain development is altered leading to a range of neurobiological and behavioral phenotypes of interest to schizophrenia. While glutamate and gamma aminobutyric acid (GABA) systems have been little investigated in these models, alterations in developing dopamine systems are frequently reported. There have been far more studies reporting patients with schizophrenia have an increased risk of vitamin D deficiency compared to well controls. Here we have conducted a systematic review and meta-analysis that basically confirms this association and extends this to first-episode psychosis. However, patients with schizophrenia also have poorer general health, poorer diets, are frequently less active and also have an increased risk of other medical conditions, all factors which reduce circulating vitamin D levels. Therefore, we would urge caution in any causal interpretation of this association. We also summarize the inconsistent results from existing vitamin D supplementation trials in patients with schizophrenia. In respect to animal models of adult vitamin D deficiency, such exposures produce subtle neurochemical alterations and effects on cognition but do not appear to produce behavioral phenotypes of relevance to schizophrenia. We conclude, the hypothesis that vitamin D deficiency during early life may increase the risk of schizophrenia remains plausible and warrants ongoing research.
Topics: Animals; Cognition; Dopamine; Humans; Schizophrenia; Vitamin D; Vitamin D Deficiency
PubMed: 33500553
DOI: 10.1038/s41380-021-01025-0 -
International Journal of Environmental... Aug 2022There is evidence of an association between cancer and certain types of altered eating behaviors, including orthorexia, food cravings, and food addiction. Given the... (Meta-Analysis)
Meta-Analysis Review
There is evidence of an association between cancer and certain types of altered eating behaviors, including orthorexia, food cravings, and food addiction. Given the growing interest in the topic throughout the scientific community we conducted a systematic review to summarize current evidence on the development of altered food behavior, including food addiction and cancer. The Cochrane Collaboration and the Meta-analysis Of Observational Studies in Epidemiology guidelines were followed to perform this systematic review. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to report the process and results. The structured literature search was conducted on 19 April 2022, on PubMed/Medline and Scopus, combining free-text terms and medical subject headings. A total of seven articles were included once the selection process was completed. Food craving has been associated with different types of cancer in adults and young patients, as well as with orthorexia; conversely, compulsive eating has only been explored in patients with prolactinoma treated with dopamine agonists. This systematic review explored a new area of research that warrants further investigation. More research is required to better understand the relationship between cancer and food behavior.
Topics: Adult; Feeding Behavior; Humans; Neoplasms; Observational Studies as Topic; PubMed
PubMed: 36011935
DOI: 10.3390/ijerph191610299 -
Journal of Neural Transmission (Vienna,... Sep 2022The trajectory of the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) is variable and doses may need to be increased, but also tapered. The plan... (Review)
Review
The trajectory of the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) is variable and doses may need to be increased, but also tapered. The plan for dose adjustment is usually done as per drug information recommendations from the licensing bodies, but there are no clear guidelines with regards to the best practice regarding the tapering off schedule given sudden dose reductions of drugs such as dopamine agonists may have serious adverse consequences. A systematic literature search was, therefore, performed to derive recommendations and the data show that there are no controlled studies or evidence-based recommendations how to taper or discontinue PD medication in a systematic manner. Most of the data were available on the dopamine agonist withdrawal syndrome (DAWS) and we found only two instructions on how to reduce pramipexole and rotigotine published by the EMA. We suggest that based on the available data, levodopa, dopamine agonists (DA), and amantadine should not be discontinued abruptly. Abrupt or sudden reduction of DA or amantadine in particular can lead to severe life-threatening withdrawal symptoms. Tapering off levodopa, COMT inhibitors, and MAO-B inhibitors may worsen motor and non-motor symptoms. Based on our clinical experience, we have proposed how to reduce PD medication and this work will form the basis of a future Delphi panel to define the recommendations in a consensus.
Topics: Amantadine; Dopamine; Dopamine Agonists; Humans; Levodopa; Parkinson Disease; Substance Withdrawal Syndrome
PubMed: 34324057
DOI: 10.1007/s00702-021-02389-x -
Biomedicines Mar 2023Treatment resistant schizophrenia (TRS) is characterized by a lack of, or suboptimal response to, antipsychotic agents. The biological underpinnings of this clinical... (Review)
Review
Treatment resistant schizophrenia (TRS) is characterized by a lack of, or suboptimal response to, antipsychotic agents. The biological underpinnings of this clinical condition are still scarcely understood. Since all antipsychotics block dopamine D2 receptors (D2R), dopamine-related mechanisms should be considered the main candidates in the neurobiology of antipsychotic non-response, although other neurotransmitter systems play a role. The aims of this review are: (i) to recapitulate and critically appraise the relevant literature on dopamine-related mechanisms of TRS; (ii) to discuss the methodological limitations of the studies so far conducted and delineate a theoretical framework on dopamine mechanisms of TRS; and (iii) to highlight future perspectives of research and unmet needs. Dopamine-related neurobiological mechanisms of TRS may be multiple and putatively subdivided into three biological points: (1) D2R-related, including increased D2R levels; increased density of D2Rs in the high-affinity state; aberrant D2R dimer or heteromer formation; imbalance between D2R short and long variants; extrastriatal D2Rs; (2) presynaptic dopamine, including low or normal dopamine synthesis and/or release compared to responder patients; and (3) exaggerated postsynaptic D2R-mediated neurotransmission. Future points to be addressed are: (i) a more neurobiologically-oriented phenotypic categorization of TRS; (ii) implementation of neurobiological studies by directly comparing treatment resistant vs. treatment responder patients; (iii) development of a reliable animal model of non-response to antipsychotics.
PubMed: 36979877
DOI: 10.3390/biomedicines11030895 -
Journal of Geriatric Psychiatry and... Sep 2022Orthostatic hypotension (OH) is multifactorial in Parkinson's disease (PD). Antiparkinsonian medication can contribute to OH, leading to increased risk of falls,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Orthostatic hypotension (OH) is multifactorial in Parkinson's disease (PD). Antiparkinsonian medication can contribute to OH, leading to increased risk of falls, weakness and fatigue.
METHODS
We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) of antiparkinsonian drugs associated with OH as an adverse effect, compared to placebo. We searched EMBASE, MEDLINE and Web of Science databases until November 2020. Analysis used fixed-effects models and the GRADE tool to rate quality of evidence. Meta-analysis was performed if 3 or more studies of a drug group were available.
RESULTS
Twenty-one RCTs including 3783 patients were included comparing 6 PD drug groups to placebo (MAO-B inhibitors, dopamine agonists, levodopa, COMT inhibitors, levodopa and adenosine receptor antagonists). OH was recorded as an adverse event or measurement of vital signs, without further specification on how this was defined or operationalised. Meta-analysis was performed for MAO-B inhibitors and dopamine agonists, as there were 3 or more studies for these drug groups. In this analysis, compared with placebo, neither MAO-B inhibitors or dopamine agonists were associated with increased risk of OH, (OR 2.28 [95% CI:0.81-6.46]), (OR 1.39 [95% CI:0.97-1.98]).
CONCLUSIONS
Most studies did not specifically report OH, or reporting of OH was limited, including how and when it was measured. Furthermore, studies specifically reporting OH included participants that were younger than typical PD populations without multimorbidity. Future trials should address this, for example,, by including individuals over the age of 75, to improve estimations of how antiparkinsonian medications affect risk of OH.
Topics: Antiparkinson Agents; Dopamine Agonists; Humans; Hypotension, Orthostatic; Levodopa; Monoamine Oxidase; Parkinson Disease
PubMed: 34964392
DOI: 10.1177/08919887211060017 -
Journal of Environmental Science and... 2016Tobacco smoking is currently on the rise among women, and can pose a greater health risk. In order to understand the nature of the increase in smoking prevalence among... (Review)
Review
Tobacco smoking is currently on the rise among women, and can pose a greater health risk. In order to understand the nature of the increase in smoking prevalence among women, we focused on the vulnerability of women to smoking behaviors--smoking cessation or tobacco addiction--and performed a systematic review of the socioeconomic and intrinsic factors as well as tobacco ingredients that affect women's susceptibility to smoking tobacco. We observed that nicotine and other tobacco components including cocoa-relatives, licorice products, and menthol aggravate tobacco addiction in women rather than in men. Various genetic and epigenetic alterations in dopamine pathway and the pharmaco-kinetics and -dynamic factors of nicotine also showed potential evidences for high susceptibility to tobacco addiction in women. Therefore, we suggest systemic approaches to prevent tobacco smoking-related health risks, considering gene-environment-gender interaction.
Topics: Behavior, Addictive; Epigenesis, Genetic; Female; Genetic Predisposition to Disease; Hormones; Humans; Male; Menthol; Nicotine; Smoking; Smoking Cessation; Smoking Prevention; Socioeconomic Factors
PubMed: 26669465
DOI: 10.1080/10590501.2015.1131539