9 research outputs found

    Assessing the Psychedelic "After-Glow" in Ayahuasca Users : Post-Acute Neurometabolic and Functional Connectivity Changes Are Associated with Enhanced Mindfulness Capacities

    Get PDF
    Ayahuasca is a plant tea containing the psychedelic 5-HT agonist N,N -dimethyltryptamine and harmala monoamine-oxidase inhibitors. Acute administration leads to neurophysiological modifications in brain regions of the default mode network, purportedly through a glutamatergic mechanism. Post-acutely, ayahuasca potentiates mindfulness capacities in volunteers and induces rapid and sustained antidepressant effects in treatment-resistant patients. However, the mechanisms underlying these fast and maintained effects are poorly understood. Here, we investigated in an open-label uncontrolled study in 16 healthy volunteers ayahuasca-induced post-acute neurometabolic and connectivity modifications and their association with mindfulness measures. Using 1 H-magnetic resonance spectroscopy and functional connectivity, we compared baseline and post-acute neurometabolites and seed-to-voxel connectivity in the posterior and anterior cingulate cortex after a single ayahuasca dose. Magnetic resonance spectroscopy showed post-acute reductions in glutamate+glutamine, creatine, and N-acetylaspartate+N-acetylaspartylglutamate in the posterior cingulate cortex. Connectivity was increased between the posterior cingulate cortex and the anterior cingulate cortex, and between the anterior cingulate cortex and limbic structures in the right medial temporal lobe. Glutamate+glutamine reductions correlated with increases in the "nonjudging" subscale of the Five Facets Mindfulness Questionnaire. Increased anterior cingulate cortex-medial temporal lobe connectivity correlated with increased scores on the self-compassion questionnaire. Post-acute neural changes predicted sustained elevations in nonjudging 2 months later. These results support the involvement of glutamate neurotransmission in the effects of psychedelics in humans. They further suggest that neurometabolic changes in the posterior cingulate cortex, a key region within the default mode network, and increased connectivity between the anterior cingulate cortex and medial temporal lobe structures involved in emotion and memory potentially underlie the post-acute psychological effects of ayahuasca

    Adhesio interthalamica alterations in schizophrenia spectrum disorders: A systematic review and meta-analysis

    No full text
    Magnetic resonance imaging (MRI) studies have reported a variety of brain abnormalities in association with schizophrenia. These include a higher prevalence of an absent adhesio interthalamica (Al; also known massa intermedia), a gray matter junction that is present between the two thalami in approximately 80% of healthy subjects. in this meta-analytic review, we describe and discuss the main Al MRI findings in schizophrenia spectrum disorders (SSDs) to date. the MEDLINE and ISI Web of Knowledge(SM) databases were searched up to December 2010, for studies that used MRI to assess Al in patients with SSD and controls. From fourteen potential reports, eleven were eligible to be part of the current review. These studies included 822 patients with SSD and 718 healthy volunteers. There was a large degree of variability in the MRI methods they employed. Patients with SSD had a higher prevalence of absent Al than healthy volunteers (odds ratio = 1.98; 95% confidence interval 1.33-2.94: p=0.0008). This association was evident in both male and female SSD subjects, and there was no evidence that the prevalence was related to age or duration of illness. the significance of the absence of an Al for SSD may be clarified by studies in large, longitudinal community-based samples using standardized methods. (C) 2011 Elsevier Inc. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)USP, FMRP, Sch Med, Dept Neurosci & Behav Sci, BR-14048900 Ribeirao Preto, SP, BrazilKings Coll London, Inst Psychiat, Dept Psychosis, London, EnglandUniv São Paulo, Sch Med, Dept Psychiat, São Paulo, BrazilUniv Fed Bahia, Affect Disorders Ctr, Salvador, BA, BrazilUniversidade Federal de São Paulo, Post Grad Program, São Paulo, BrazilLiNC, São Paulo, BrazilUniversidade Federal de São Paulo, Post Grad Program, São Paulo, BrazilCAPES: 5797/09-8Web of Scienc

    Are cavum septum pellucidum abnormalities more common in schizophrenia spectrum disorders? A systematic review and meta-analysis

    No full text
    Magnetic resonance imaging (MRI) studies have reported a variety of brain abnormalities in association with schizophrenia. These include a higher incidence of cavum septum pellucidum (CSP), which is consistent with a neurodevelopmental model for this disorder. in this meta-analytic review, we describe and discuss the main CSP MRI findings in schizophrenia spectrum disorders (SSDs) to date. We adopted as keywords cavum and schizophrenia or psychosis, and the inclusion criteria were articles in English, with samples of SSD patients compared to healthy subjects, which used MRI to assess CSP, without time limit. From 18 potential reports, fifteen were eligible to be part of the current review. These studies included 1054 patients with SSD and 866 healthy volunteers. Six out of 15 studies pointed to a higher prevalence of CSP of any size in SSD patients, while five out of 15 showed that subjects with SSD had a greater occurrence of a large CSP than healthy individuals. However, the meta-analysis demonstrated that only the incidence of a large CSP was significantly higher in SSD relative to healthy comparisons (odds ratio = 1.59; 95%CI 1.07-2.38; p = 0.02). Overall our results suggest that only a large CSP is associated with SSD while a small CSP may be considered a normal neuroanatomical variation. Our review revealed a large degree of variability in the methods employed across the MRI studies published to date, as well as evidence of publication bias. Studies in large, community-based samples with greater standardization of methods should clarify the true significance of CSP in SSD. (C) 2010 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo, Sch Med, Dept Neurobiol & Behav, BR-14048900 Ribeirao Preto, SP, BrazilKings Coll London, Inst Psychiat, Dept Psychosis Studies, London, EnglandUniv Fed Bahia, Affect Disorders Ctr, Salvador, BA, BrazilUniversidade Federal de São Paulo, Post Grad Program, São Paulo, BrazilLab Interdisciplinar Neurociencias Clin, São Paulo, BrazilUniv São Paulo, Sch Med, Dept Psychiat, São Paulo, BrazilUniversidade Federal de São Paulo, Post Grad Program, São Paulo, BrazilCAPES: 5797/09-8Web of Scienc

    Assessing the Psychedelic "After-Glow" in Ayahuasca Users : Post-Acute Neurometabolic and Functional Connectivity Changes Are Associated with Enhanced Mindfulness Capacities

    No full text
    Ayahuasca is a plant tea containing the psychedelic 5-HT agonist N,N -dimethyltryptamine and harmala monoamine-oxidase inhibitors. Acute administration leads to neurophysiological modifications in brain regions of the default mode network, purportedly through a glutamatergic mechanism. Post-acutely, ayahuasca potentiates mindfulness capacities in volunteers and induces rapid and sustained antidepressant effects in treatment-resistant patients. However, the mechanisms underlying these fast and maintained effects are poorly understood. Here, we investigated in an open-label uncontrolled study in 16 healthy volunteers ayahuasca-induced post-acute neurometabolic and connectivity modifications and their association with mindfulness measures. Using 1 H-magnetic resonance spectroscopy and functional connectivity, we compared baseline and post-acute neurometabolites and seed-to-voxel connectivity in the posterior and anterior cingulate cortex after a single ayahuasca dose. Magnetic resonance spectroscopy showed post-acute reductions in glutamate+glutamine, creatine, and N-acetylaspartate+N-acetylaspartylglutamate in the posterior cingulate cortex. Connectivity was increased between the posterior cingulate cortex and the anterior cingulate cortex, and between the anterior cingulate cortex and limbic structures in the right medial temporal lobe. Glutamate+glutamine reductions correlated with increases in the "nonjudging" subscale of the Five Facets Mindfulness Questionnaire. Increased anterior cingulate cortex-medial temporal lobe connectivity correlated with increased scores on the self-compassion questionnaire. Post-acute neural changes predicted sustained elevations in nonjudging 2 months later. These results support the involvement of glutamate neurotransmission in the effects of psychedelics in humans. They further suggest that neurometabolic changes in the posterior cingulate cortex, a key region within the default mode network, and increased connectivity between the anterior cingulate cortex and medial temporal lobe structures involved in emotion and memory potentially underlie the post-acute psychological effects of ayahuasca

    A randomized trial of planned cesarean or vaginal delivery for twin pregnancy

    No full text
    Background: Twin birth is associated with a higher risk of adverse perinatal outcomes than singleton birth. It is unclear whether planned cesarean section results in a lower risk of adverse outcomes than planned vaginal delivery in twin pregnancy.\ud \ud Methods: We randomly assigned women between 32 weeks 0 days and 38 weeks 6 days of gestation with twin pregnancy and with the first twin in the cephalic presentation to planned cesarean section or planned vaginal delivery with cesarean only if indicated. Elective delivery was planned between 37 weeks 5 days and 38 weeks 6 days of gestation. The primary outcome was a composite of fetal or neonatal death or serious neonatal morbidity, with the fetus or infant as the unit of analysis for the statistical comparison.\ud \ud Results: A total of 1398 women (2795 fetuses) were randomly assigned to planned cesarean delivery and 1406 women (2812 fetuses) to planned vaginal delivery. The rate of cesarean delivery was 90.7% in the planned-cesarean-delivery group and 43.8% in the planned-vaginal-delivery group. Women in the planned-cesarean-delivery group delivered earlier than did those in the planned-vaginal-delivery group (mean number of days from randomization to delivery, 12.4 vs. 13.3; P = 0.04). There was no significant difference in the composite primary outcome between the planned-cesarean-delivery group and the planned-vaginal-delivery group (2.2% and 1.9%, respectively; odds ratio with planned cesarean delivery, 1.16; 95% confidence interval, 0.77 to 1.74; P = 0.49).\ud \ud Conclusion: In twin pregnancy between 32 weeks 0 days and 38 weeks 6 days of gestation, with the first twin in the cephalic presentation, planned cesarean delivery did not significantly decrease or increase the risk of fetal or neonatal death or serious neonatal morbidity, as compared with planned vaginal delivery
    corecore