-
Journal of Psychiatric Research Nov 2023The benefits of serotonin 3 receptor antagonists (5-HT3R-As) in obsessive-compulsive disorder (OCD) treatment remain unclear. Thus, this study aimed to perform a... (Meta-Analysis)
Meta-Analysis
The benefits of serotonin 3 receptor antagonists (5-HT3R-As) in obsessive-compulsive disorder (OCD) treatment remain unclear. Thus, this study aimed to perform a systematic review and a random-effects meta-analysis, including double-blind, randomized, placebo-controlled trials (DBRPCTs). The outcomes include the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) total score (primary), Y-BOCS obsession subscale score, Y-BOCS compulsive subscale score, treatment response, remission rate, all-cause discontinuation, and incidence of individual adverse events (nervousness/restlessness/anxiety, insomnia, headache, dizziness/lightheadedness, decreased appetite, constipation, nausea/vomiting, diarrhea, dry mouth, sweating/increased perspiration, itching/pruritus, tremor, and sexual dysfunction/decreased libido). The mean differences (MD) for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals (CIs) were calculated. Our study included 10 DBRPCTs (n = 628). Pooled 5-HT3R-As outperformed placebo regarding Y-BOCS total score (MD = -5.08, 95% CI = -7.04, -3.12, N = 9, n = 560), Y-BOCS obsession subscale score, Y-BOCS compulsive subscale score, treatment response, and remission rate. Individually, all 5-HT3R-As outperformed placebo regarding Y-BOCS total score (granisetron: MD = -5.59, 95% CI = -8.79, -2.39, N = 3, n = 178, ondansetron: MD = -5.72, 95% CI = -8.06, -3.37, N = 6, n = 331, tropisetron: MD = -2.87, 95% CI = -5.19, -0.550, N = 1, n = 96). However, all-cause discontinuation and incidence of individual adverse events between pooled 5-HT3R-As and placebo were not significantly different. In conclusion, our meta-analysis suggested 5-HT3R-As as efficacious for symptom improvement in individuals with OCD. However, the number of individuals included in each study was small; thus, a replication randomized trial of 5-HT3R-As should be conducted using a larger sample size.
Topics: Humans; Obsessive-Compulsive Disorder; Serotonin 5-HT3 Receptor Antagonists; Randomized Controlled Trials as Topic; Outcome Assessment, Health Care
PubMed: 37866327
DOI: 10.1016/j.jpsychires.2023.10.029 -
The 5-HT7 receptor system as a treatment target for mood and anxiety disorders: A systematic review.Journal of Psychopharmacology (Oxford,... Dec 2023Preclinical animal and preliminary human studies indicate that 5-HT7 antagonists have the potential as a new treatment approach for mood and anxiety disorders. In this... (Review)
Review
BACKGROUND
Preclinical animal and preliminary human studies indicate that 5-HT7 antagonists have the potential as a new treatment approach for mood and anxiety disorders. In this systematic review, we aimed to review the relationship between the 5-HT7 receptor system and mood and anxiety disorders, and to explore the pharmacology and therapeutic potential of medications that target the 5-HT7 receptor for their treatment.
METHODS
Medline, Cochrane Library, EMBASE, PsycINFO databases, the National Institute of Health website Clinicaltrials.gov, controlled-trials.com, and relevant grey literature were used to search for original research articles, and reference lists of included articles were then hand searched.
RESULTS
Sixty-four studies were included in the review: 52 animal studies and 12 human studies. Studies used a variety of preclinical paradigms and questionnaires to assess change in mood, and few studies examined sleep or cognition. Forty-four out of 47 (44/47) preclinical 5-HT7 modulation studies identified potential antidepressant effects and 20/23 studies identified potential anxiolytic effects. In clinical studies, 5/7 identified potential antidepressant effects in major depressive disorder, 1/2 identified potential anxiolytic effects in generalized anxiety disorder, and 3/3 identified potential antidepressant effects in bipolar disorders.
CONCLUSION
While there is some evidence that the 5-HT7 receptor system may be a potential target for treating mood and anxiety disorders, many agents included in the review also bind to other receptors. Further research is needed using drugs that bind specifically to 5-HT7 receptors to examine treatment proof of concept further.
Topics: Animals; Humans; Anti-Anxiety Agents; Antidepressive Agents; Anxiety Disorders; Depressive Disorder, Major
PubMed: 37994803
DOI: 10.1177/02698811231211228 -
Eating and Weight Disorders : EWD Apr 2024Several studies have investigated the association between anorexia nervosa and polymorphisms of genes regulating serotonin neurotransmission, with a focus on the rs6311... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Several studies have investigated the association between anorexia nervosa and polymorphisms of genes regulating serotonin neurotransmission, with a focus on the rs6311 polymorphism of 5-HTR2A. However, inconsistent results of these studies and conflicting conclusions of existing meta-analyses complicate the understanding of a possible association. We have updated these results and evaluated the involvement of other serotonin receptor gene polymorphisms in anorexia nervosa.
METHODS
Adhering to PRISMA guidelines, we have searched studies on anorexia nervosa and serotonin-regulating genes published from 1997 to 2022, selected those concerning receptor genes and meta-analyzed the results from twenty candidate gene studies on the 5-HTR2A rs6311 polymorphism and the 5-HTR2C rs6318 polymorphism.
RESULTS
Present analyses reveal an association for the 5-HTR2A rs6311 polymorphism, with G and A alleles, across eighteen studies (2049 patients, 2877 controls; A vs. G allele, Odds Ratio = 1.24; 95% Confidence Interval = 1.06-1.47; p = 0.009). However, after geographic subgrouping, an association emerged only in a Southern European area, involving five studies (722 patients, 773 controls; A vs. G allele, Odds Ratio = 1.82; 95% Confidence Interval = 1.41-2.37; p < 0.00001). No association was observed for the 5-HTR2C rs6318 polymorphism across three studies.
CONCLUSIONS
To date, the involvement in the pathophysiology of anorexia nervosa of the 5-HTR2A rs6311 polymorphism appears limited to a specific genetic and/or environmental context, while that of the 5-HTR2C rs6318 polymorphism seems excluded. Genome-wide association studies and epigenetic studies will likely offer deeper insights of genetic and environmental factors possibly contributing to the disorder.
LEVEL OF EVIDENCE
III Evidence obtained from well-designed cohort or case-control analytic studies. Clinical trial registration PROSPERO registration number: CRD42021246122.
Topics: Humans; Anorexia Nervosa; Genetic Predisposition to Disease; Polymorphism, Single Nucleotide; Receptor, Serotonin, 5-HT2A; Receptor, Serotonin, 5-HT2C
PubMed: 38668826
DOI: 10.1007/s40519-024-01659-3 -
Frontiers in Physiology 2022Endocannabinoids (eCBS) are endogenously derived lipid signaling molecules that serve as tissue hormones and interact with multiple targets, mostly within the...
Endocannabinoids (eCBS) are endogenously derived lipid signaling molecules that serve as tissue hormones and interact with multiple targets, mostly within the endocannabinoid system (ECS). The ECS is a highly conserved regulatory system involved in homeostatic regulation, organ formation, and immunomodulation of chordates. The term "cannabinoid" evolved from the distinctive class of plant compounds found in , an ancient herb, due to their action on CB1 and CB2 receptors. CB1/2 receptors are the primary targets for eCBs, but their effects are not limited to the ECS. Due to the high interest and extensive research on the ECS, knowledge on its constituents and physiological role is substantial and still growing. Crosstalk and multiple targeting of molecules are common features of endogenous and plant compounds. Cannabimimetic molecules can be divided according to their origin, natural or synthetic, including phytocannabinoids (pCB's) or synthetic cannabinoids (sCB's). The endocannabinoid system (ECS) consists of receptors, transporters, enzymes, and signaling molecules. In this review, we focus on the effects of cannabinoids on Cys-loop receptors. Cys-loop receptors belong to the class of membrane-bound pentameric ligand gated ion channels, each family comprising multiple subunits. Mammalians possess GABA type A receptors (GABAAR), glycine receptors (GlyR), serotonin receptors type 3 (5-HT3R), and nicotinic acetylcholine receptors (nAChR). Several studies have shown different modulatory effects of CBs on multiple members of the Cys-loop receptor family. We highlight the existing knowledge, especially on subunits and protein domains with conserved binding sites for CBs and their possible pharmacological and physiological role in epilepsy and in chronic pain. We further discuss the potential for cannabinoids as first line treatments in epilepsy, chronic pain and other neuropsychiatric conditions, indicated by their polypharmacology and therapeutic profile.
PubMed: 36439263
DOI: 10.3389/fphys.2022.1044575 -
Scientific Reports Nov 2023Obsessive-compulsive disorder (OCD) is the fourth most common mental disorder, and selective serotonin reuptake inhibitors (SSRIs) are the cornerstone of its... (Meta-Analysis)
Meta-Analysis
Efficacy and safety of 5-hydroxytryptamine-3 (5-HT3) receptor antagonists in augmentation with selective serotonin reuptake inhibitors (SSRIs) in the treatment of moderate to severe obsessive-compulsive disorder: a systematic review and meta-analysis of randomized clinical trials.
Obsessive-compulsive disorder (OCD) is the fourth most common mental disorder, and selective serotonin reuptake inhibitors (SSRIs) are the cornerstone of its pharmacological treatment. About 40-60% of the cases are treatment-refractory, and this makes searching for second-line treatment necessary. 5-Hydroxytryptamine-3 (5-HT3) antagonists are among the many medications that have been used in augmentation with SSRIs. In this systematic review and meta-analysis, we assessed the efficacy and safety of 5-HT3 receptor antagonists in augmentation with SSRIs in treating moderate to severe OCD. We searched PubMed, Web of Science, Scopus, Cochrane library, and Google Scholar for relevant trials published up to December 2022. The effect size was the mean difference in Yale-Brown obsessive compulsive scale (Y-BOCS) scores before and after receiving 5-HT3 receptor antagonist drugs in augmentation with SSRIs in moderate to severe OCD patients. We included 6 randomized-controlled trails (RCTs) with 334 patients assessing the effect of the augmentation of SSRIs with ondansetron, granisetron, and tropisetron on treating moderate to severe OCD. Our results were in favor of the experimental group in total (Z = 8.37, P < 0.00001), in the compulsion subgroup (Z = 5.22, P < 0.00001), and in the obsession subgroup (Z = 8.33, P < 0.00001). They are well-tolerated, and have mild side effects and do not result in withdrawal. Augmentation of 5-HT3 antagonists with SSRIs can be beneficial in treating moderate to severe OCD. Further multi-center trials under adequate conditions in longer periods are needed to help come up with a comprehensive action plan.
Topics: Humans; Selective Serotonin Reuptake Inhibitors; Serotonin; Receptors, Serotonin, 5-HT3; Treatment Outcome; Randomized Controlled Trials as Topic; Obsessive-Compulsive Disorder; Drug Therapy, Combination
PubMed: 38012263
DOI: 10.1038/s41598-023-47931-x -
Herbal medicines for insomnia through regulating 5-hydroxytryptamine receptors: a systematic review.Chinese Journal of Natural Medicines Jul 2023Insomnia is a common sleep disorder without effective therapy and can affect a person's life. The mechanism of the disease is not completely understood. Hence, there is... (Review)
Review
Insomnia is a common sleep disorder without effective therapy and can affect a person's life. The mechanism of the disease is not completely understood. Hence, there is a need to understand the targets related to insomnia, in order to develop innovative therapies and new compounds. Recently, increasing interest has been focused on complementary and alternative medicines for treating or preventing insomnia. Research into their molecular components has revealed that their sedative and sleep-promoting properties rely on the interactions with various neurotransmitter systems in the brain. In this review, the role of 5-hydroxytryptamine (5-HT) in insomnia development is summarized, while a systematic analysis of studies is conducted to assess the mechanisms of herbal medicines on different 5-HT receptors subtypes, in order to provide reference for subsequent research.
Topics: Sleep Initiation and Maintenance Disorders; Plants, Medicinal; Receptors, Serotonin; Serotonin; Sleep; Humans; Animals
PubMed: 37517817
DOI: 10.1016/S1875-5364(23)60405-4 -
Frontiers in Neuroendocrinology Jul 2023The rapid and continual development of a number of radiopharmaceuticals targeting different receptor, enzyme and small molecule systems has fostered Positron Emission... (Review)
Review
The rapid and continual development of a number of radiopharmaceuticals targeting different receptor, enzyme and small molecule systems has fostered Positron Emission Tomography (PET) imaging of endocrine system actions in vivo in the human brain for several decades. PET radioligands have been developed to measure changes that are regulated by hormone action (e.g., glucose metabolism, cerebral blood flow, dopamine receptors) and actions within endocrine organs or glands such as steroids (e.g., glucocorticoids receptors), hormones (e.g., estrogen, insulin), and enzymes (e.g., aromatase). This systematic review is targeted to the neuroendocrinology community that may be interested in learning about positron emission tomography (PET) imaging for use in their research. Covering neuroendocrine PET research over the past half century, researchers and clinicians will be able to answer the question of where future research may benefit from the strengths of PET imaging.
Topics: Humans; Neuroendocrinology; Positron-Emission Tomography; Radiopharmaceuticals; Brain
PubMed: 37423505
DOI: 10.1016/j.yfrne.2023.101081 -
Journal of Affective Disorders Nov 2022Depression and atherosclerotic cardiovascular disease (ASCVD) are commonly clustered in affected patients. Endothelial dysfunction is an early marker of ASCVD while also... (Meta-Analysis)
Meta-Analysis Review
AIMS
Depression and atherosclerotic cardiovascular disease (ASCVD) are commonly clustered in affected patients. Endothelial dysfunction is an early marker of ASCVD while also reported in patients with depression. Emerging evidence suggests that selective serotonin receptor inhibitors (SSRIs) may improve endothelial function. However, clinical studies assessing flow-mediated dilation (FMD), the gold-standard method to evaluate conduit artery endothelial function, in response to SSRIs treatment included limited number of patients and did not provide consistent results. In the present study we aim to evaluate the effect of SSRIs treatment on endothelial function assessed by longitudinal changes in FMD.
METHODS AND RESULTS
We performed a systematic review to retrieve and subsequently meta-analyze eligible studies in patients with depression who received SSRIs and had available measurements of FMD change before and after treatment. In 5 studies and 323 individuals in total, SSRIs were associated with increased FMD at the end of follow-up compared to baseline measurement (pooled mean change 1.97 %, 95 % CI 0.17, 3.77, P = 0.032, I = 87.4 %). These results did not substantially change when analysis was restricted to patients with history of atherosclerotic cardiovascular disease (ASCVD). Similarly, FMD changes were higher in individuals receiving SSRIs compared to not-treated subjects (pooled mean difference 2.5 %. 95 % CI 0.7, 4.2, P < 0.001, I = 82.7 %).
LIMITATIONS
Substantial heterogeneity regarding with respect to follow-up duration, demographics, and SSRIs agents.
CONCLUSION
SSRIs significantly improve FMD, the gold-standard marker of endothelial function. Further investigation is warranted for the role of FMD as a possible therapeutic biomarker in patients with depression and established or subclinical ASCVD.
PROSPERO REGISTRATION
CRD42021252241.
Topics: Cardiovascular Diseases; Endothelium, Vascular; Humans; Selective Serotonin Reuptake Inhibitors
PubMed: 35944740
DOI: 10.1016/j.jad.2022.08.007 -
Journal of Psychoactive Drugs Jun 2023Evidence suggests that psilocybin has therapeutic benefit for treating depression. However, there is little consensus regarding the mechanism by which psilocybin elicits... (Review)
Review
Evidence suggests that psilocybin has therapeutic benefit for treating depression. However, there is little consensus regarding the mechanism by which psilocybin elicits antidepressant effects. This systematic review summarizes existing evidence. Ovid MEDLINE, EMBASE, psychINFO, and Web of Science were searched, for both human and animal studies, using a combination of MeSH Terms and free-text keywords in September 2021. No other mood disorders or psychiatric diagnoses were included. Original papers in English were included. The PRISMA framework was followed for the screening of papers. Two researchers screened the retrieved articles from the literature search, and a third researcher resolved any conflicts. Of 2,193 papers identified, 49 were selected for full-text review. 14 articles were included in the qualitative synthesis. Six supported psilocybin's mechanism of antidepressant action via changes to serotonin or glutamate receptor activity and three papers found an increase in synaptogenesis. Thirteen papers investigated changes in non-receptor or pathway-specific brain activity. Five papers found changes in functional connectivity or neurotransmission, most commonly in the hippocampus or prefrontal cortex. Several neuroreceptors, neurotransmitters, and brain areas are thought to be involved in psilocybin's ability to mitigate depressive symptoms. Psilocybin appears to alter cerebral blood flow to the amygdala and prefrontal cortex, but the evidence on changes in functional connectivity and specific receptor activity remains sparse. The lack of consensus between studies suggests that psilocybin's mechanism of action may involve a variety of pathways, demonstrating the need for more studies on psilocybin's mechanism of action as an antidepressant.
PubMed: 37385217
DOI: 10.1080/02791072.2023.2223195 -
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