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Raphaël Gaillard

16 papers in the library · 836 citations · publishing 2009-2026

Papers

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French psychiatric caregivers' perceptions of psychedelics: A national survey.

L'Encephale October 16, 2026 Anne Buot, Jean-Del Burdairon, Luc Mallet et al.

The use of psychedelic substances such as LSD, psilocybin, and dimethyltryptamine is currently being re-evaluated for their therapeutic potential in psychiatry. While international clinical research had started in the 2010s, France only initiated its first psychedelic trials in 2024. This study aimed to explore the knowledge, perceptions, and attitudes of French mental health professionals...

Trauma re-experiencing episodes during esketamine treatment in patients with treatment-resistant depression and comorbid PTSD: a retrospective case series.

European Journal of Psychotraumatology April 1, 2026 Maud Rothärmel, Lila Mekaoui, François Kazour et al. 1 citation

Background: Posttraumatic stress disorder (PTSD) is a severe and frequent affection that is highly comorbid to major depressive disorder. Comorbid PTSD and depression increase the risk of treatment-resistant depression (TRD), with a high risk of functional impairment and suicide. Esketamine nasal spray is a recent validated treatment for TRD, but its efficacy on comorbid TRD-PTSD remains...

Mystical Experience Induced by Esketamine Treatment: A Real-World Observational Study

medRxiv Preprint Server March 31, 2026 Maia Mallevays, Louise Fuet, Michel Danon et al. 1 citation preprint

Esketamine is a fast-acting antidepressant drug which induces acute psychoactive effects. The most frequent is a dissociative state which seems unrelated to therapeutic efficacy. Other esketamine-induced effects, including psychedelic-like mystical experiences, have been poorly studied in terms of phenomenology and frequency, and may carry specific therapeutic relevance. In this study, we...

Ketamine disrupts consciousness in healthy participants in relation with psychotic-like symptoms.

bioRxiv : the preprint server for biology November 8, 2025 Lucie Berkovitch, Alexandre Salvador, Thomas Andrillon et al. preprint

Ketamine is an NMDA-receptor antagonist, which alters the state of wakeful consciousness at high doses. At lower doses, it induces reversible psychotic-like symptoms and has been used as a pharmacological model of psychosis. In this study, we explore whether low doses of ketamine disrupt conscious access in relation with its psychotomimetic effects, and investigate the neural correlates of its...

Neurocognitive effects of psilocybin: A systematic and comprehensive review of neuroimaging studies in humans.

Neuroscience & Biobehavioral Reviews August 1, 2025 Lucie Berkovitch, Baptiste Fauvel, Katrin H. Preller et al. 8 citations

Psilocybin is a psychedelic serotonergic compound that is renowned for its potent psychoactive effects. Over the past 15 years, an increasing number of controlled clinical trials showed that it has a fast-acting and sustainable efficacy in treating various psychiatric disorders. Neuroimaging studies have been conducted with the objective of elucidating the neurobiological mechanisms underlying...

Distinct alterations in probabilistic reversal learning across at-risk mental state, first episode psychosis and persistent schizophrenia.

Scientific Reports July 30, 2024 J. D. Griffin, K. M. J. Diederen, J. Haarsma et al. 5 citations

We used a probabilistic reversal learning task to examine prediction error-driven belief updating in three clinical groups with psychosis or psychosis-like symptoms. Study 1 compared people with at-risk mental state and first episode psychosis (FEP) to matched controls. Study 2 compared people diagnosed with treatment-resistant schizophrenia (TRS) to matched controls. The design replicated our...

DOI: 10.1038/s41598-024-68004-7 (opens in new tab) Full text (opens in new tab) Psychosis Schizophrenia Decision-making Cognitive behavior +1

Early effects predict trajectories of response to esketamine in treatment-resistant depression.

Journal of Affective Disorders September 20, 2023 Isaure Estrade, Anne-Cécile Petit, Vincent Sylvestre et al.

Background: The efficacy of esketamine in treatment-resistant depression (TRD) has been confirmed. However, its administration is expensive and restrictive, with limited knowledge on how long the treatment should be continued. Predicting the treatment outcome would benefit patients and alleviate the global treatment cost. We aimed to define distinct trajectories of treatment response and assess...

Efficacy and Safety of Intranasal Esketamine in Patients With Treatment-Resistant Depression and Comorbid Chronic Post-traumatic Stress Disorder: Open-Label Single-Arm Pilot Study

Frontiers in Psychiatry July 8, 2022 Maud Rothärmel, Cherifa Benosman, Wissam El-Hage et al. 31 citations

Introduction: Major depressive disorder (MDD) is more likely to resist to usual treatment when it is associated with post-traumatic stress disorder (PTSD). Capitalizing on the effect of ketamine in both treatment-resistant depression (TRD) and PTSD, we conducted a study in order to assess the efficacy of intranasal (IN) Esketamine in patients having TRD with comorbid PTSD. Materials and...

Ketamine for the acute treatment of severe suicidal ideation: double blind, randomised placebo controlled trial

British medical journal February 2, 2022 M. Abbar, C. Demattei, Wissam El-Hage et al. 172 citations

Abstract Objective To confirm the rapid onset anti-suicidal benefits of ketamine in the short term and at six weeks, overall and according to diagnostic group. Design Prospective, double blind, superiority, randomised placebo controlled trial. Setting Seven French teaching hospitals between 13 April 2015 and 12 March 2019. Eligibility criteria for participants Aged 18 or older with current...

[Efficacy of psychedelics in psychiatry, a systematic review of the literature].

L'Encephale August 1, 2021 Lucie Berkovitch, Bruno Romeo, Laurent Karila et al. 25 citations

Psychedelics are powerful psychoactive substances. Natural psychedelics have been used for millennia by human civilizations, in particular in Latin America, while synthetic psychedelics were discovered in the 50s, giving rise to a lot of research before they were prohibited. More recently, their therapeutic properties have been studied especially to help patients with psychiatric conditions,...

Disruption of Conscious Access in Psychosis Is Associated with Altered Structural Brain Connectivity

Journal of Neuroscience November 23, 2020 Lucie Berkovitch, Lucie Charles, Antoine del Cul et al.

According to global neuronal workspace (GNW) theory, conscious access relies on long-distance cerebral connectivity to allow a global neuronal ignition coding for conscious content. In patients with schizophrenia and bipolar disorder, both alterations in cerebral connectivity and an increased threshold for conscious perception have been reported. The implications of abnormal structural...

Efficacy and Safety of Fixed-Dose Esketamine Nasal Spray Combined With a New Oral Antidepressant in Treatment-Resistant Depression: Results of a Randomized, Double-Blind, Active-Controlled Study (TRANSFORM-1)

The International Journal of Neuropsychopharmacology July 9, 2019 Maggie Fedgchin, Madhukar H. Trivedi, Ella Daly et al. 593 citations

BACKGROUND: About one-third of patients with depression fail to achieve remission despite treatment with multiple antidepressants and are considered to have treatment-resistant depression. METHODS: This Phase 3, double-blind, multicenter study enrolled adults with moderate-to-severe depression and nonresponse to ≥2 antidepressants in the current depression episode. Eligible patients (N = 346)...

Conscious and unconscious performance monitoring: Evidence from patients with schizophrenia.

Neuroimage 2017 Lucie Charles, Raphaël Gaillard, Isabelle Amado et al.

The ability to detect our own errors is an essential component of action monitoring. Using a masking paradigm in normal adults, we recently discovered that some error-detection processes can proceed without awareness, while other markers of performance monitoring such as the Error-Related Negativity (ERN) are tightly linked to conscious perception. Interestingly, research on cognitive deficit...

The role of GSK-3 in treatment-resistant depression and links with the pharmacological effects of lithium and ketamine: A review of the literature.

L'Encephale April 2016 J F Costemale-Lacoste, J P Guilloux, Raphaël Gaillard

Since the discovery of antidepressants, new treatments have emerged with fewer side effects but no greater efficacy. Glycogen synthase kinase 3 β (GSK-3β), a kinase known for its activity on glycogen synthesis, has in the last few years raised growing interest in biological psychiatry. Several efficient treatments in major depression have an inhibitory effect on this kinase, which could be...

Confidence and psychosis: a neuro-computational account of contingency learning disruption by NMDA blockade.

Molecular Psychiatry June 9, 2015 Fabien Vinckier, Raphaël Gaillard, S Palminteri et al.

A state of pathological uncertainty about environmental regularities might represent a key step in the pathway to psychotic illness. Early psychosis can be investigated in healthy volunteers under ketamine, an NMDA receptor antagonist. Here, we explored the effects of ketamine on contingency learning using a placebo-controlled, double-blind, crossover design. During functional magnetic...

DOI: 10.1038/mp.2015.73 (opens in new tab) Full text (opens in new tab) Ketamine Humans Psychoses, substance-induced Receptors, n-methyl-d-aspartate +8

Converging intracranial markers of conscious access.

PLoS Biology March 1, 2009 Raphaël Gaillard, Stanislas Dehaene, Claude Adam et al.

We compared conscious and nonconscious processing of briefly flashed words using a visual masking procedure while recording intracranial electroencephalogram (iEEG) in ten patients. Nonconscious processing of masked words was observed in multiple cortical areas, mostly within an early time window (<300 ms), accompanied by induced gamma-band activity, but without coherent long-distance neural...

DOI: 10.1371/journal.pbio.1000061 (opens in new tab) Full text (opens in new tab) Cerebral cortex Humans Epilepsy Electroencephalography +9