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1.
JMIR Form Res ; 8: e54632, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38437005

RESUMEN

This study demonstrates that changes in mindfulness predict subsequent changes in well-being in a data set including individuals who recently engaged in psychedelic use.

2.
bioRxiv ; 2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-38464275

RESUMEN

N,N-Dimethyltryptamine (DMT) is a serotonergic psychedelic, known to rapidly induce short-lasting alterations in conscious experience, characterized by a profound and immersive sense of physical transcendence alongside rich and vivid auditory distortions and visual imagery. Multimodal neuroimaging data paired with dynamic analysis techniques offer a valuable approach for identifying unique signatures of brain activity - and linked autonomic physiology - naturally unfolding during the altered state of consciousness induced by DMT. We leveraged simultaneous fMRI and EKG data acquired in 14 healthy volunteers prior to, during, and after intravenous administration of DMT, and, separately, placebo. fMRI data was preprocessed to derive individual dynamic activity matrices, reflecting the similarity of brain activity in time, and community detection algorithms were applied on these matrices to identify brain activity substates; EKG data was used to derive continuous heart rate. We identified a brain substate occurring immediately after DMT injection, characterized by hippocampal and medial parietal deactivations and increased superior temporal lobe activity under DMT. Deactivations in the hippocampus and medial parietal cortex correlated with alterations in the usual sense of time, space and self-referential processes, reflecting a deconstruction of essential features of ordinary consciousness. Superior lobe activations instead correlated with audio/visual hallucinations and experience of "entities", reflecting the emergence of altered sensory experiences under DMT. Finally, increased heart rate under DMT correlated positively with hippocampus/medial parietal deactivation and the experience of "entities", and negatively with altered self-referential processes. These results suggest a chain of influence linking sympathetic regulation to hippocampal and medial parietal deactivations under DMT, which combined, may contribute to positive mental health outcomes related to self-referential processing following psychedelic administration.

3.
Neuroimage ; 283: 120414, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37858906

RESUMEN

The role of the thalamus in mediating the effects of lysergic acid diethylamide (LSD) was recently proposed in a model of communication and corroborated by imaging studies. However, a detailed analysis of LSD effects on nuclei-resolved thalamocortical connectivity is still missing. Here, in a group of healthy volunteers, we evaluated whether LSD intake alters the thalamocortical coupling in a nucleus-specific manner. Structural and resting-state functional Magnetic Resonance Imaging (MRI) data were acquired in a placebo-controlled study on subjects exposed to acute LSD administration. Structural MRI was used to parcel the thalamus into its constituent nuclei based on individual anatomy. Nucleus-specific changes of resting-state functional MRI (rs-fMRI) connectivity were mapped using a seed-based approach. LSD intake selectively increased the thalamocortical functional connectivity (FC) of the ventral complex, pulvinar, and non-specific nuclei. Functional coupling was increased between these nuclei and sensory cortices that include the somatosensory and auditory networks. The ventral and pulvinar nuclei also exhibited increased FC with parts of the associative cortex that are dense in serotonin type 2A receptors. These areas are hyperactive and hyper-connected upon LSD intake. At subcortical levels, LSD increased the functional coupling among the thalamus's ventral, pulvinar, and non-specific nuclei, but decreased the striatal-thalamic connectivity. These findings unravel some LSD effects on the modulation of subcortical-cortical circuits and associated behavioral outputs.


Asunto(s)
Pulvinar , Tálamo , Humanos , Tálamo/fisiología , Imagen por Resonancia Magnética , Corteza Cerebral/diagnóstico por imagen , Lóbulo Parietal , Vías Nerviosas
4.
J Affect Disord ; 333: 321-330, 2023 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-37094657

RESUMEN

BACKGROUND: Psychedelic-assisted psychotherapy with psilocybin is an emerging therapy with great promise for depression, and modern psychedelic therapy (PT) methods incorporate music as a key element. Music is an effective emotional/hedonic stimulus that could also be useful in assessing changes in emotional responsiveness following PT. METHODS: Brain responses to music were assessed before and after PT using functional Magnetic Resonance Imaging (fMRI) and ALFF (Amplitude of Low Frequency Fluctuations) analysis methods. Nineteen patients with treatment-resistant depression underwent two treatment sessions involving administration of psilocybin, with MRI data acquired one week prior and the day after completion of psilocybin dosing sessions. RESULTS: Comparison of music-listening and resting-state scans revealed significantly greater ALFF in bilateral superior temporal cortex for the post-treatment music scan, and in the right ventral occipital lobe for the post-treatment resting-state scan. ROI analyses of these clusters revealed a significant effect of treatment in the superior temporal lobe for the music scan only. Voxelwise comparison of treatment effects showed relative increases for the music scan in the bilateral superior temporal lobes and supramarginal gyrus, and relative decreases in the medial frontal lobes for the resting-state scan. ALFF in these music-related clusters was significantly correlated with intensity of subjective effects felt during the dosing sessions. LIMITATIONS: Open-label trial. Relatively small sample size. CONCLUSIONS: These data suggest an effect of PT on the brain's response to music, implying an elevated responsiveness to music after psilocybin therapy that was related to subjective drug effects felt during dosing.


Asunto(s)
Alucinógenos , Música , Humanos , Encéfalo/fisiología , Mapeo Encefálico , Depresión , Alucinógenos/uso terapéutico , Imagen por Resonancia Magnética/métodos , Psilocibina/farmacología , Psilocibina/uso terapéutico
5.
J Psychopharmacol ; 37(1): 70-79, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36433778

RESUMEN

BACKGROUND: Music listening is a staple and valued component of psychedelic therapy, and previous work has shown that psychedelics can acutely enhance music-evoked emotion. AIMS: The present study sought to examine subjective responses to music before and after psilocybin therapy for treatment-resistant depression, while functional magnetic resonance imaging (fMRI) data was acquired. METHODS: Nineteen patients with treatment-resistant depression received a low oral dose (10 mg) of psilocybin, and a high dose (25 mg) 1 week later. fMRI was performed 1 week prior to the first dosing session and 1 day after the second. Two scans were conducted on each day: one with music and one without. Visual analogue scale ratings of music-evoked 'pleasure' plus ratings of other evoked emotions (21-item Geneva Emotional Music Scale) were completed after each scan. Given its role in musical reward, the nucleus accumbens (NAc) was chosen as region of interest for functional connectivity (FC) analyses. Effects of drug (vs placebo) and music (vs no music) on subjective and FC outcomes were assessed. Anhedonia symptoms were assessed pre- and post-treatment (Snaith-Hamilton Pleasure Scale). RESULTS: Results revealed a significant increase in music-evoked emotion following treatment with psilocybin that correlated with post-treatment reductions in anhedonia. A post-treatment reduction in NAc FC with areas resembling the default mode network was observed during music listening (vs no music). CONCLUSION: These results are consistent with current thinking on the role of psychedelics in enhancing music-evoked pleasure and provide some new insight into correlative brain mechanisms.


Asunto(s)
Alucinógenos , Música , Humanos , Psilocibina/farmacología , Psilocibina/uso terapéutico , Música/psicología , Alucinógenos/farmacología , Alucinógenos/uso terapéutico , Anhedonia/fisiología , Depresión/tratamiento farmacológico , Emociones , Imagen por Resonancia Magnética
6.
Sci Rep ; 12(1): 8562, 2022 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-35610230

RESUMEN

Understanding the phenomenology and content of the inhaled N, N, dimethyltryptamine (N, N-DMT) experience is critical to facilitate and support ongoing research and therapeutic models targeting mental health conditions and central nervous system pathology. A qualitative analysis was conducted of all N, N-DMT experiences posted to the r/DMT Reddit community over a 10-year period from 2009 to 2018. A total of 3778 experiences from 3305 posts were included in this study. A median dose of N, N-DMT of 40.0 mg [interquartile range (IQR), 27.5 to 50.0] and a median experience duration of 10 min (IQR, 5.0 to 15.0) were identified. The most common somatic effects were somaesthesias (n = 1415, 37.5%) and an auditory ringing (n = 583, 15.4%). Visualizations predominantly consisted of fractals, shapes, patterns (n = 1231, 32.6%) and vivid colours (n = 953, 25.2%). Entity encounters were reported in 45.5% (n = 1719) of the experiences and involved predominantly a feminine phenotype (n = 416, 24.2%); deities (n = 293, 17.0%); aliens (n = 281, 16.3%); creature-based entities (n = 158, 9.2%, including reptilian and insectoid beings); mythological beings (n = 144, 8.4%, including machine elves); and jesters (n = 112, 6.5%). Entity interactions were predominantly positive (n = 600, 34.9% of encounters) involving benevolent, comforting, protecting, or outwardly caring interactions. A companion-type, pedagogical, or guide-type interaction was identified 32.4% of encounters (n = 557). Common typology, architecture, and structural features of the "DMT world" included descriptions of alternate or higher dimensions (n = 952, 25.2%); rooms [n = 582, 15.4%, including the "waiting room" (n = 105, 2.8%)], and a tunnel (n = 390, 10.3%). Features of mystical and ego-dissolution experiences were common. Additional rewarding aspects were identified, including a sense of familiarity and the acceptance/removal of the fear of death. Challenging and difficult responses were less frequent but also documented. Statements of profundity were identified in 232 experiences (6.1%), including pronouncing the experience or an aspect of the experience as the most "beautiful" or feeling the most "beautiful" of their life (n = 47, 1.2%). This study identified common phenomenological themes and content of naturalistic inhaled N, N-DMT experiences. Major thematic domains included (1) physical and somatic experiences; (2) visualizations and imagery; (3) entity encounters including entity phenotype, descriptors, attributes, disposition, and characteristics of the interaction; (4) typology, architectural features, structural characteristics, and scenery of the "DMT world"; (5) alerations in consciousness (including mystical experiences, out-of-body experiences, and ego-dissolution); (6) emotional responses (including positive, rewarding, difficult, and challenging); and (7) statements of profundity.


Asunto(s)
Alucinógenos , Emociones , Miedo , Alucinógenos/farmacología , N,N-Dimetiltriptamina , Trastornos Fóbicos
7.
J Psychopharmacol ; 35(4): 406-420, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33567945

RESUMEN

BACKGROUND: N,N-dimethyltryptamine is a short-acting psychedelic tryptamine found naturally in many plants and animals. Few studies to date have addressed the neural and psychological effects of N,N-dimethyltryptamine alone, either administered intravenously or inhaled in freebase form, and none have been conducted in natural settings. AIMS: Our primary aim was to study the acute effects of inhaled N,N-dimethyltryptamine in natural settings, focusing on questions tuned to the advantages of conducting field research, including the effects of contextual factors (i.e. "set" and "setting"), the possibility of studying a comparatively large number of subjects, and the relaxed mental state of participants consuming N,N-dimethyltryptamine in familiar and comfortable settings. METHODS: We combined state-of-the-art wireless electroencephalography with psychometric questionnaires to study the neural and subjective effects of naturalistic N,N-dimethyltryptamine use in 35 healthy and experienced participants. RESULTS: We observed that N,N-dimethyltryptamine significantly decreased the power of alpha (8-12 Hz) oscillations throughout all scalp locations, while simultaneously increasing power of delta (1-4 Hz) and gamma (30-40 Hz) oscillations. Gamma power increases correlated with subjective reports indicative of some features of mystical-type experiences. N,N-dimethyltryptamine also increased global synchrony and metastability in the gamma band while decreasing those measures in the alpha band. CONCLUSIONS: Our results are consistent with previous studies of psychedelic action in the human brain, while at the same time the results suggest potential electroencephalography markers of mystical-type experiences in natural settings, thus highlighting the importance of investigating these compounds in the contexts where they are naturally consumed.


Asunto(s)
Trastornos de la Conciencia , Electroencefalografía/métodos , Misticismo/psicología , N,N-Dimetiltriptamina , Inventario de Personalidad , Terapia por Relajación/métodos , Administración por Inhalación , Adulto , Disponibilidad Biológica , Trastornos de la Conciencia/inducido químicamente , Trastornos de la Conciencia/diagnóstico , Monitoreo de Drogas/métodos , Femenino , Alucinógenos/administración & dosificación , Alucinógenos/farmacocinética , Humanos , Masculino , N,N-Dimetiltriptamina/administración & dosificación , N,N-Dimetiltriptamina/farmacocinética , Evaluación de Resultado en la Atención de Salud , Psicometría/métodos , Autoimagen , Autoinforme , Tecnología Inalámbrica
8.
J Psychopharmacol ; 35(4): 319-352, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33174492

RESUMEN

This paper introduces a new construct, the 'pivotal mental state', which is defined as a hyper-plastic state aiding rapid and deep learning that can mediate psychological transformation. We believe this new construct bears relevance to a broad range of psychological and psychiatric phenomena. We argue that pivotal mental states serve an important evolutionary function, that is, to aid psychological transformation when actual or perceived environmental pressures demand this. We cite evidence that chronic stress and neurotic traits are primers for a pivotal mental state, whereas acute stress can be a trigger. Inspired by research with serotonin 2A receptor agonist psychedelics, we highlight how activity at this particular receptor can robustly and reliably induce pivotal mental states, but we argue that the capacity for pivotal mental states is an inherent property of the human brain itself. Moreover, we hypothesize that serotonergic psychedelics hijack a system that has evolved to mediate rapid and deep learning when its need is sensed. We cite a breadth of evidences linking stress via a variety of inducers, with an upregulated serotonin 2A receptor system (e.g. upregulated availability of and/or binding to the receptor) and acute stress with 5-HT release, which we argue can activate this primed system to induce a pivotal mental state. The pivotal mental state model is multi-level, linking a specific molecular gateway (increased serotonin 2A receptor signaling) with the inception of a hyper-plastic brain and mind state, enhanced rate of associative learning and the potential mediation of a psychological transformation.


Asunto(s)
Alucinógenos/farmacología , Misticismo , Plasticidad Neuronal , Trastornos Psicóticos , Receptor de Serotonina 5-HT2A/metabolismo , Agonistas del Receptor de Serotonina 5-HT2/farmacología , Estrés Psicológico , Aspiraciones Psicológicas , Aprendizaje por Asociación/efectos de los fármacos , Aprendizaje por Asociación/fisiología , Humanos , Atención Plena/métodos , Plasticidad Neuronal/efectos de los fármacos , Plasticidad Neuronal/fisiología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/fisiología , Estrés Psicológico/metabolismo , Estrés Psicológico/psicología , Estrés Psicológico/terapia
9.
Front Psychol ; 9: 1475, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30245648

RESUMEN

In recent years, the scientific study of meditation and psychedelic drugs has seen remarkable developments. The increased focus on meditation in cognitive neuroscience has led to a cross-cultural classification of standard meditation styles validated by functional and structural neuroanatomical data. Meanwhile, the renaissance of psychedelic research has shed light on the neurophysiology of altered states of consciousness induced by classical psychedelics, such as psilocybin and LSD, whose effects are mainly mediated by agonism of serotonin receptors. Few attempts have been made at bridging these two domains of inquiry, despite intriguing evidence of overlap between the phenomenology and neurophysiology of meditation practice and psychedelic states. In particular, many contemplative traditions explicitly aim at dissolving the sense of self by eliciting altered states of consciousness through meditation, while classical psychedelics are known to produce significant disruptions of self-consciousness, a phenomenon known as drug-induced ego dissolution. In this article, we discuss available evidence regarding convergences and differences between phenomenological and neurophysiological data on meditation practice and psychedelic drug-induced states, with a particular emphasis on alterations of self-experience. While both meditation and psychedelics may disrupt self-consciousness and underlying neural processes, we emphasize that neither meditation nor psychedelic states can be conceived as simple, uniform categories. Moreover, we suggest that there are important phenomenological differences even between conscious states described as experiences of self-loss. As a result, we propose that self-consciousness may be best construed as a multidimensional construct, and that "self-loss," far from being an unequivocal phenomenon, can take several forms. Indeed, various aspects of self-consciousness, including narrative aspects linked to autobiographical memory, self-related thoughts and mental time travel, and embodied aspects rooted in multisensory processes, may be differently affected by psychedelics and meditation practices. Finally, we consider long-term outcomes of experiences of self-loss induced by meditation and psychedelics on individual traits and prosocial behavior. We call for caution regarding the problematic conflation of temporary states of self-loss with "selflessness" as a behavioral or social trait, although there is preliminary evidence that correlations between short-term experiences of self-loss and long-term trait alterations may exist.

10.
Psychopharmacology (Berl) ; 235(5): 1623, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29582103

RESUMEN

The article The hidden therapist: evidence for a central role of music in psychedelic therapy, written by Mendel Kaelen, Bruna Giribaldi, Jordan Raine, Lisa Evans, Christopher Timmerman, Natalie Rodriguez, Leor Roseman, Amanda Feilding, David Nutt, Robin Carhart-Harris, was originally published electronically on the publisher's internet portal.

11.
Psychopharmacology (Berl) ; 235(2): 505-519, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29396616

RESUMEN

RATIONALE: Recent studies have supported the safety and efficacy of psychedelic therapy for mood disorders and addiction. Music is considered an important component in the treatment model, but little empirical research has been done to examine the magnitude and nature of its therapeutic role. OBJECTIVES: The present study assessed the influence of music on the acute experience and clinical outcomes of psychedelic therapy. METHODS: Semi-structured interviews inquired about the different ways in which music influenced the experience of 19 patients undergoing psychedelic therapy with psilocybin for treatment-resistant depression. Interpretative phenomenological analysis was applied to the interview data to identify salient themes. In addition, ratings were given for each patient for the extent to which they expressed "liking," "resonance" (the music being experienced as "harmonious" with the emotional state of the listener), and "openness" (acceptance of the music-evoked experience). RESULTS: Analyses of the interviews revealed that the music had both "welcome" and "unwelcome" influences on patients' subjective experiences. Welcome influences included the evocation of personally meaningful and therapeutically useful emotion and mental imagery, a sense of guidance, openness, and the promotion of calm and a sense of safety. Conversely, unwelcome influences included the evocation of unpleasant emotion and imagery, a sense of being misguided and resistance. Correlation analyses showed that patients' experience of the music was associated with the occurrence of "mystical experiences" and "insightfulness." Crucially, the nature of the music experience was significantly predictive of reductions in depression 1 week after psilocybin, whereas general drug intensity was not. CONCLUSIONS: This study indicates that music plays a central therapeutic function in psychedelic therapy.


Asunto(s)
Trastorno Depresivo Resistente al Tratamiento/psicología , Trastorno Depresivo Resistente al Tratamiento/terapia , Alucinógenos/administración & dosificación , Musicoterapia/métodos , Psilocibina/administración & dosificación , Psicoterapia/métodos , Adulto , Percepción Auditiva/efectos de los fármacos , Percepción Auditiva/fisiología , Trastorno Depresivo Resistente al Tratamiento/diagnóstico , Emociones/efectos de los fármacos , Emociones/fisiología , Femenino , Humanos , Masculino , Música/psicología
12.
Lancet Psychiatry ; 3(7): 619-27, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27210031

RESUMEN

BACKGROUND: Psilocybin is a serotonin receptor agonist that occurs naturally in some mushroom species. Recent studies have assessed the therapeutic potential of psilocybin for various conditions, including end-of-life anxiety, obsessive-compulsive disorder, and smoking and alcohol dependence, with promising preliminary results. Here, we aimed to investigate the feasibility, safety, and efficacy of psilocybin in patients with unipolar treatment-resistant depression. METHODS: In this open-label feasibility trial, 12 patients (six men, six women) with moderate-to-severe, unipolar, treatment-resistant major depression received two oral doses of psilocybin (10 mg and 25 mg, 7 days apart) in a supportive setting. There was no control group. Psychological support was provided before, during, and after each session. The primary outcome measure for feasibility was patient-reported intensity of psilocybin's effects. Patients were monitored for adverse reactions during the dosing sessions and subsequent clinic and remote follow-up. Depressive symptoms were assessed with standard assessments from 1 week to 3 months after treatment, with the 16-item Quick Inventory of Depressive Symptoms (QIDS) serving as the primary efficacy outcome. This trial is registered with ISRCTN, number ISRCTN14426797. FINDINGS: Psilocybin's acute psychedelic effects typically became detectable 30-60 min after dosing, peaked 2-3 h after dosing, and subsided to negligible levels at least 6 h after dosing. Mean self-rated intensity (on a 0-1 scale) was 0·51 (SD 0·36) for the low-dose session and 0·75 (SD 0·27) for the high-dose session. Psilocybin was well tolerated by all of the patients, and no serious or unexpected adverse events occurred. The adverse reactions we noted were transient anxiety during drug onset (all patients), transient confusion or thought disorder (nine patients), mild and transient nausea (four patients), and transient headache (four patients). Relative to baseline, depressive symptoms were markedly reduced 1 week (mean QIDS difference -11·8, 95% CI -9·15 to -14·35, p=0·002, Hedges' g=3·1) and 3 months (-9·2, 95% CI -5·69 to -12·71, p=0·003, Hedges' g=2) after high-dose treatment. Marked and sustained improvements in anxiety and anhedonia were also noted. INTERPRETATION: This study provides preliminary support for the safety and efficacy of psilocybin for treatment-resistant depression and motivates further trials, with more rigorous designs, to better examine the therapeutic potential of this approach. FUNDING: Medical Research Council.


Asunto(s)
Trastorno Depresivo Resistente al Tratamiento/tratamiento farmacológico , Psilocibina/uso terapéutico , Agonistas de Receptores de Serotonina/uso terapéutico , Apoyo Social , Adulto , Trastorno Depresivo Resistente al Tratamiento/psicología , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Psilocibina/efectos adversos , Resultado del Tratamiento
13.
Eur Neuropsychopharmacol ; 26(7): 1099-109, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27084302

RESUMEN

Psychedelic drugs such as lysergic acid diethylamide (LSD) were used extensively in psychiatry in the past and their therapeutic potential is beginning to be re-examined today. Psychedelic psychotherapy typically involves a patient lying with their eyes-closed during peak drug effects, while listening to music and being supervised by trained psychotherapists. In this context, music is considered to be a key element in the therapeutic model; working in synergy with the drug to evoke therapeutically meaningful thoughts, emotions and imagery. The underlying mechanisms involved in this process have, however, never been formally investigated. Here we studied the interaction between LSD and music-listening on eyes-closed imagery by means of a placebo-controlled, functional magnetic resonance imaging (fMRI) study. Twelve healthy volunteers received intravenously administered LSD (75µg) and, on a separate occasion, placebo, before being scanned under eyes-closed resting conditions with and without music-listening. The parahippocampal cortex (PHC) has previously been linked with (1) music-evoked emotion, (2) the action of psychedelics, and (3) mental imagery. Imaging analyses therefore focused on changes in the connectivity profile of this particular structure. Results revealed increased PHC-visual cortex (VC) functional connectivity and PHC to VC information flow in the interaction between music and LSD. This latter result correlated positively with ratings of enhanced eyes-closed visual imagery, including imagery of an autobiographical nature. These findings suggest a plausible mechanism by which LSD works in combination with music listening to enhance certain subjective experiences that may be useful in a therapeutic context.


Asunto(s)
Percepción Auditiva/efectos de los fármacos , Alucinógenos/farmacología , Imaginación/efectos de los fármacos , Dietilamida del Ácido Lisérgico/farmacología , Música , Giro Parahipocampal/efectos de los fármacos , Administración Intravenosa , Adulto , Percepción Auditiva/fisiología , Mapeo Encefálico , Femenino , Humanos , Imaginación/fisiología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/efectos de los fármacos , Vías Nerviosas/fisiología , Giro Parahipocampal/diagnóstico por imagen , Giro Parahipocampal/fisiología , Descanso , Percepción Visual/efectos de los fármacos , Percepción Visual/fisiología , Adulto Joven
14.
Schizophr Bull ; 39(6): 1343-51, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23044373

RESUMEN

Psilocybin is a classic psychedelic and a candidate drug model of psychosis. This study measured the effects of psilocybin on resting-state network and thalamocortical functional connectivity (FC) using functional magnetic resonance imaging (fMRI). Fifteen healthy volunteers received intravenous infusions of psilocybin and placebo in 2 task-free resting-state scans. Primary analyses focused on changes in FC between the default-mode- (DMN) and task-positive network (TPN). Spontaneous activity in the DMN is orthogonal to spontaneous activity in the TPN, and it is well known that these networks support very different functions (ie, the DMN supports introspection, whereas the TPN supports externally focused attention). Here, independent components and seed-based FC analyses revealed increased DMN-TPN FC and so decreased DMN-TPN orthogonality after psilocybin. Increased DMN-TPN FC has been found in psychosis and meditatory states, which share some phenomenological similarities with the psychedelic state. Increased DMN-TPN FC has also been observed in sedation, as has decreased thalamocortical FC, but here we found preserved thalamocortical FC after psilocybin. Thus, we propose that thalamocortical FC may be related to arousal, whereas DMN-TPN FC is related to the separateness of internally and externally focused states. We suggest that this orthogonality is compromised in early psychosis, explaining similarities between its phenomenology and that of the psychedelic state and supporting the utility of psilocybin as a model of early psychosis.


Asunto(s)
Cerebro/fisiopatología , Conectoma/métodos , Alucinógenos/farmacología , Red Nerviosa/efectos de los fármacos , Psilocibina/farmacología , Trastornos Psicóticos/fisiopatología , Adulto , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/fisiopatología , Cerebro/efectos de los fármacos , Conectoma/instrumentación , Femenino , Alucinógenos/administración & dosificación , Alucinógenos/efectos adversos , Humanos , Masculino , Red Nerviosa/fisiopatología , Psilocibina/administración & dosificación , Psilocibina/efectos adversos , Psicosis Inducidas por Sustancias/fisiopatología , Reproducibilidad de los Resultados , Tálamo/efectos de los fármacos , Tálamo/fisiopatología , Adulto Joven
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