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Rothärmel M, Mekaoui L, Kazour F, Herrero M, Beetz-Lobono EM, Lengvenyte A, Holtzmann J, Raynaud P, Cuenca M, Bulteau S, de Maricourt P, Husson T, Olié E, Gohier B, Sauvaget A, Gaillard R, Richieri R, Szekely D, Samalin L, Guillin O, Moulier V, El-Hage W, Laurin A, Berkovitch L. Esketamine-induced post-traumatic stress disorder flashbacks during treatment-resistant depression indication: is it just a side effect? MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.09.24300998. [PMID: 38293161 PMCID: PMC10827260 DOI: 10.1101/2024.01.09.24300998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Background Posttraumatic stress disorder (PTSD) is a severe and frequent affection that is highly comorbid to major depressive disorder. Comorbid PTSD and depression are usually treatment-resistant, with a high risk of functional impairment and suicide. Esketamine nasal spray is a recent validated treatment for treatment-resistant depression (TRD), but its efficacy on comorbid TRD-PTSD remains insufficiently documented. In particular, flashbacks can occur during esketamine administration and their influence on clinical outcomes is unknown. Objectives Our main objective was to describe esketamine-induced traumatic flashbacks and their impact on clinical trajectories within a sample of patients with comorbid TRD-PTSD. Methods We retrospectively collected clinical data of patients receiving esketamine nasal spray for TRD with comorbid PTSD who experienced at least one flashback of their trauma during esketamine sessions across 11 psychiatric departments. Results Between February 2020 and March 2023, 22 adult patients with TRD met inclusion criteria. In sixteen patients (72.7%) flashbacks disappeared as the sessions progressed. In six patients (27.3%), esketamine treatment was stopped because of persistent flashbacks. When esketamine was continued, clinical response was observed both for depression and PTSD (depression response rate: 45.5% and remission rate: 22.7%; PTSD response rate: 45.5% and remission: 18.2%). Limitations The retrospective design of the study and the absence of a comparator group are the main limitations of our study. Conclusions Our results suggest that the occurrence of esketamine-induced traumatic flashbacks does not hinder clinical response. On the contrary, when managed appropriately and combined with targeted psychotherapy, it could even contribute to positive outcomes.
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Affiliation(s)
- Maud Rothärmel
- University Department of Psychiatry, Therapeutic Centre of Excellence, Institute of Psychiatry – Rouvray Hospital Centre, Sotteville-lès-Rouen, France
| | - Lila Mekaoui
- Mental and Brain Illness Clinic, Sainte-Anne Hospital, GHU Paris – Psychiatry and Neurosciences, Paris, France
| | - François Kazour
- Department of Psychiatry and Addictology, CHU Angers, Angers, France
| | - Morgane Herrero
- Department of Psychiatry, CHU Saint Etienne, Saint Etienne, France
| | | | - Aiste Lengvenyte
- Department of Emergency Psychiatry and Post-Acute Care, CHU Montpellier, France; IGF, Univ. Montpellier, CNRS, INSERM, Montpellier, France
| | - Jérôme Holtzmann
- Service de Psychiatrie de l’Adulte, Centre Expert Dépression Résistante FondaMental, CHU de Grenoble, hôpital Nord, Grenoble, France
| | | | - Macarena Cuenca
- University Department of Psychiatry, Pôle Hospitalo-Universitaire Psychiatrie Paris 15, Groupe Hospitalier Universitaire Paris, Paris, France
| | - Samuel Bulteau
- Nantes Université, CHU Nantes, INSERM, MethodS in Patients-centered outcomes and HEalth Research, SPHERE, F-44000 Nantes, France
| | - Pierre de Maricourt
- University Department of Psychiatry, Pôle Hospitalo-Universitaire Psychiatrie Paris 15, Groupe Hospitalier Universitaire Paris, Paris, France
| | - Thomas Husson
- University Department of Psychiatry, Therapeutic Centre of Excellence, Institute of Psychiatry – Rouvray Hospital Centre, Sotteville-lès-Rouen, France
| | - Emilie Olié
- Department of Emergency Psychiatry and Post-Acute Care, CHU Montpellier, France; IGF, Univ. Montpellier, CNRS, INSERM, Montpellier, France
| | - Bénédicte Gohier
- Department of Psychiatry and Addictology, CHU Angers, Angers, France
| | - Anne Sauvaget
- Nantes Université, CHU Nantes, INSERM, MethodS in Patients-centered outcomes and HEalth Research, SPHERE, F-44000 Nantes, France
| | - Raphaël Gaillard
- University Department of Psychiatry, Pôle Hospitalo-Universitaire Psychiatrie Paris 15, Groupe Hospitalier Universitaire Paris, Paris, France
| | - Raphaëlle Richieri
- Service Universitaire de santé mentale et physique, Centre Expert Dépression Résistante, CHU Sainte-Marguerite, APHM, Université Aix-Marseille, Marseille, France; Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
| | - David Szekely
- Centre Hospitalier Princesse Grace, Service de psychiatrie, Principauté de Monaco
| | - Ludovic Samalin
- Department of Psychiatry, CHU Clermont-Ferrand, University of Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal (UMR 6602), Clermont-Ferrand, France
| | - Olivier Guillin
- University Department of Psychiatry, Therapeutic Centre of Excellence, Institute of Psychiatry – Rouvray Hospital Centre, Sotteville-lès-Rouen, France
- CHU Rouen, Normandy University, Rouen, France
| | - Virginie Moulier
- University Department of Psychiatry, Therapeutic Centre of Excellence, Institute of Psychiatry – Rouvray Hospital Centre, Sotteville-lès-Rouen, France
- Unité de Recherche Clinique (URC), EPS Ville Evrard, Neuilly-sur-Marne, France
| | - Wissam El-Hage
- Centre Régional de Psychotraumatologie, Centre Hospitalier Régional
- Universitaire (CHRU) de Tours, Tours, France, 3 INSERM U1253 Imagerie et Cerveau (iBrain), Tours, France
| | - Andrew Laurin
- Nantes Université, CHU Nantes, INSERM, MethodS in Patients-centered outcomes and HEalth Research, SPHERE, F-44000 Nantes, France
| | - Lucie Berkovitch
- University Department of Psychiatry, Pôle Hospitalo-Universitaire Psychiatrie Paris 15, Groupe Hospitalier Universitaire Paris, Paris, France
- Paris Cité University, Paris, France
- Department of Psychiatry, Yale University School of Medicine, 40 Temple Street, New Haven, CT, 06511, United States
- Saclay CEA Centre, Neurospin, Gif-Sur-Yvette Cedex, France
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Deng J, Lin X, Zheng Y, Su S, Liu X, Yuan K, Shi L, Bao Y, Lu L. Manipulating critical memory periods to treat psychiatry disorders. Sci Bull (Beijing) 2023; 68:2477-2486. [PMID: 37689533 DOI: 10.1016/j.scib.2023.08.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/10/2023] [Accepted: 08/27/2023] [Indexed: 09/11/2023]
Abstract
The persistence of pathological memory is the basis of several psychiatric disorders. Memory retrieval induces "reconsolidation", a time interval during which the original memory becomes labile and destabilized. Time- and retrieval-dependent processes and memory reconsolidation are critical periods for memory interference. Modulating memory reconsolidation has received considerable research attention as a treatment protocol for several psychiatric conditions such as posttraumatic stress disorder, addiction, anxiety, and trauma-related disorders. This specific time window provides an opportunity for intervention regarding mental diseases. This article reviews the effect of modulating memory reconsolidation using behavioral-, brain stimulation-, and pharmacological-based interventions, which may help bridge the gap between intervention in laboratories and application in clinical practice. The potential advantages, limitations, challenges, and opportunities for memory reconsolidation manipulations were discussed.
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Affiliation(s)
- Jiahui Deng
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China
| | - Xiao Lin
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China
| | - Yongbo Zheng
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China; Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Sizhen Su
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China
| | - Xiaoxing Liu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China
| | - Kai Yuan
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China
| | - Le Shi
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China
| | - Yanping Bao
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing 100191, China; School of Public Health, Peking University, Beijing 100191, China; Institute of Brain Science and Brain-inspired Research, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China.
| | - Lin Lu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China; Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China; National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing 100191, China.
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3
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Bottemanne H, Arnould A, Najar A, Delaigue F, Serresse L, Joly L, Mouchabac S. [Combination of ketamine and esketamine with Exposure and Response Prevention (ERP) therapy for Obsessive-Compulsive Disorder]. L'ENCEPHALE 2023; 49:304-311. [PMID: 37095049 DOI: 10.1016/j.encep.2022.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/24/2022] [Accepted: 08/04/2022] [Indexed: 04/26/2023]
Abstract
Obsessive-Compulsive Disorder (OCD), characterized by the combination of obsession and compulsion, is a clinical and therapeutic challenge. Many patients with OCD do not respond to first-line treatments such as serotonin selective reuptake inhibitors (SSRIs) and exposure and response prevention psychotherapy (ERP). For these resistant patients, some preliminary studies have shown that ketamine, a non-selective glutamatergic NMDA receptors antagonist, could improve the obsessive symptoms. A number of these studies have also suggested that the combination of ketamine with ERP psychotherapy may jointly potentiate the effectiveness of ketamine and ERP. In this paper, we present the existing data on the combined use of ketamine with ERP psychotherapy for OCD. We suggest that modulation of NMDA receptor activity and glutamatergic signaling by ketamine may promote the therapeutic mechanisms involved in ERP such as fear extinction and brain plasticity mechanisms. Finally, we propose a ketamine-augmented ERP psychotherapy (KAP-ERP) protocol in OCD, and we present the limitations associated with its application in clinical practice.
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Affiliation(s)
- Hugo Bottemanne
- Paris Brain Institute - Institut du Cerveau (ICM), UMR 7225/UMRS 1127, Sorbonne University/CNRS/Inserm, Paris, France; Sorbonne University, Department of Philosophy, SND Research Unit, UMR 8011, CNRS, Paris, France; Department of Psychiatry, Pitié-Salpêtrière Hospital, Sorbonne University, DMU Neuroscience, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.
| | - Alice Arnould
- Department of Psychiatry, Pitié-Salpêtrière Hospital, Sorbonne University, DMU Neuroscience, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Amaury Najar
- Department of Psychiatry, Pitié-Salpêtrière Hospital, Sorbonne University, DMU Neuroscience, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Fanny Delaigue
- Department of Psychiatry, Pitié-Salpêtrière Hospital, Sorbonne University, DMU Neuroscience, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Laure Serresse
- Sorbonne University, Unité Mobile d'Accompagnement et de Soins Palliatifs, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Lucie Joly
- Paris Brain Institute - Institut du Cerveau (ICM), UMR 7225/UMRS 1127, Sorbonne University/CNRS/Inserm, Paris, France; Department of Psychiatry, Saint Antoine Hospital, Sorbonne University, DMU Neuroscience, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Stéphane Mouchabac
- Paris Brain Institute - Institut du Cerveau (ICM), UMR 7225/UMRS 1127, Sorbonne University/CNRS/Inserm, Paris, France; Department of Psychiatry, Saint Antoine Hospital, Sorbonne University, DMU Neuroscience, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
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4
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Koller WN, Cannon TD. Aberrant memory and delusional ideation: A pernicious partnership? Clin Psychol Rev 2023; 99:102231. [PMID: 36469975 DOI: 10.1016/j.cpr.2022.102231] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/02/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022]
Abstract
Delusions can be conceptualized as beliefs that are both at odds with consensus reality and espoused with high conviction. While delusions represent a cardinal symptom of schizophrenia, delusion-like beliefs can be found in the general population. Do similar cognitive mechanisms support delusionality across this spectrum? If so, what are they? Here, we examine evidence for a mechanistic role of the (associative) memory system in the formation and maintenance of delusions and delusion-like beliefs. While general neurocognitive metrics do not tend to associate with delusionality, our scoping review of the clinical and subclinical literature reveals several subdomains of memory function that do. These include a propensity to commit errors of commission (i.e., false alarms and intrusions), source memory biases, and metamemory impairment. We discuss how several of these effects may stem from aberrant associative memory function and offer recommendations for future research. Further, we propose a state/trait interaction model in which underlying traits (i.e., impaired associative and metamemory function) may become coupled with delusionality during states of acute psychosis, when memory function is particularly challenged by aberrant salience attribution and noisy perceptual input. According to this model, delusions may arise as explanations to high-salience (but low-source) mnemonic content that is endorsed with high confidence.
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Affiliation(s)
- William N Koller
- Department of Psychology, Yale University, Hillhouse Avenue, New Haven, CT 06520-8205, United States of America.
| | - Tyrone D Cannon
- Department of Psychology, Yale University, Hillhouse Avenue, New Haven, CT 06520-8205, United States of America
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5
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Fleming LM, Jaynes FJB, Thompson SL, Corlett PR, Taylor JR. Targeted effects of ketamine on perceptual expectation during mediated learning in rats. Psychopharmacology (Berl) 2022; 239:2395-2405. [PMID: 35389087 PMCID: PMC9296571 DOI: 10.1007/s00213-022-06128-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/26/2022] [Indexed: 10/18/2022]
Abstract
RATIONALE While neural correlates of hallucinations are known, the mechanisms have remained elusive. Mechanistic insight is more practicable in animal models, in which causal relationships can be established. Recent work developing animal models of hallucination susceptibility has focused on the genesis of perceptual expectations and perceptual decision-making. Both processes are encompassed within mediated learning, which involves inducing a strong perceptual expectation via associative learning, retrieving that memory representation, and deciding whether this internally generated percept is predictive of an external outcome. Mediated learning in rodents is sensitive to many psychotomimetic manipulations. However, we do not know if these manipulations selectively alter learning of perceptual expectations versus their retrieval because of their presence throughout all task phases. OBJECTIVES Here, we used mediated learning to study the targeted effect of a psychotomimetic agent on the retrieval of perceptual expectation. METHODS We administered (R,S)-ketamine to rats selectively during the devaluation phase of a mediated learning task, when the representation of the expected cue is retrieved, to test the hypothesis that internally generated perceptual experiences underlie this altered mediated learning. RESULTS We found that ketamine increased only mediated learning at a moderate dose in rats, but impaired direct learning at the high dose. CONCLUSIONS These results suggest that ketamine can augment retrieval of perceptual expectations and thus this may be how it induces hallucination-like experiences in humans. More broadly, mediated learning may unite the conditioning, perceptual decision-making, and even reality monitoring accounts of psychosis in a manner that translates across species.
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Affiliation(s)
- Leah M Fleming
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Frances-Julia B Jaynes
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychology, University of New Haven, New Haven, CT, USA
- Department of Psychiatry, University of Connecticut Health, Farmington, CT, USA
| | - Summer L Thompson
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Philip R Corlett
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychology, Yale University, New Haven, CT, USA
| | - Jane R Taylor
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
- Department of Psychology, Yale University, New Haven, CT, USA.
- Department of Neuroscience, Yale University, New Haven, CT, USA.
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6
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Radford KD, Berman RY, Jaiswal S, Kim SY, Zhang M, Spencer HF, Choi KH. Enhanced Fear Memories and Altered Brain Glucose Metabolism ( 18F-FDG-PET) following Subanesthetic Intravenous Ketamine Infusion in Female Sprague-Dawley Rats. Int J Mol Sci 2022; 23:ijms23031922. [PMID: 35163844 PMCID: PMC8836808 DOI: 10.3390/ijms23031922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/30/2022] [Accepted: 02/04/2022] [Indexed: 11/30/2022] Open
Abstract
Although women and men are equally likely to receive ketamine following traumatic injury, little is known regarding sex-related differences in the impact of ketamine on traumatic memory. We previously reported that subanesthetic doses of an intravenous (IV) ketamine infusion following fear conditioning impaired fear extinction and altered regional brain glucose metabolism (BGluM) in male rats. Here, we investigated the effects of IV ketamine infusion on fear memory, stress hormone levels, and BGluM in female rats. Adult female Sprague–Dawley rats received a single IV ketamine infusion (0, 2, 10, or 20 mg/kg, over a 2-h period) following auditory fear conditioning (three pairings of tone and footshock). Levels of plasma stress hormones, corticosterone (CORT) and progesterone, were measured after the ketamine infusion. Two days after ketamine infusion, fear memory retrieval, extinction, and renewal were tested over a three-day period. The effects of IV ketamine infusion on BGluM were determined using 18F-fluoro-deoxyglucose positron emission tomography (18F-FDG-PET) and computed tomography (CT). The 2 and 10 mg/kg ketamine infusions reduced locomotor activity, while 20 mg/kg infusion produced reduction (first hour) followed by stimulation (second hour) of activity. The 10 and 20 mg/kg ketamine infusions significantly elevated plasma CORT and progesterone levels. All three doses enhanced fear memory retrieval, impaired fear extinction, and enhanced cued fear renewal in female rats. Ketamine infusion produced dose-dependent effects on BGluM in fear- and stress-sensitive brain regions of female rats. The current findings indicate that subanesthetic doses of IV ketamine produce robust effects on the hypothalamic–pituitary–adrenal (HPA) axis and brain energy utilization that may contribute to enhanced fear memory observed in female rats.
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Affiliation(s)
- Kennett D. Radford
- Daniel K. Inouye Graduate School of Nursing, Uniformed Services University, Bethesda, MD 20814, USA;
| | - Rina Y. Berman
- Center for the Study of Traumatic Stress, Uniformed Services University, Bethesda, MD 20814, USA; (R.Y.B.); (M.Z.)
| | - Shalini Jaiswal
- Biomedical Research Imaging Core (BRIC), Department of Radiology and Radiological Sciences, Uniformed Services University, Bethesda, MD 20814, USA;
| | - Sharon Y. Kim
- Program in Neuroscience, Uniformed Services University, Bethesda, MD 20814, USA; (S.Y.K.); (H.F.S.)
| | - Michael Zhang
- Center for the Study of Traumatic Stress, Uniformed Services University, Bethesda, MD 20814, USA; (R.Y.B.); (M.Z.)
| | - Haley F. Spencer
- Program in Neuroscience, Uniformed Services University, Bethesda, MD 20814, USA; (S.Y.K.); (H.F.S.)
| | - Kwang H. Choi
- Daniel K. Inouye Graduate School of Nursing, Uniformed Services University, Bethesda, MD 20814, USA;
- Center for the Study of Traumatic Stress, Uniformed Services University, Bethesda, MD 20814, USA; (R.Y.B.); (M.Z.)
- Program in Neuroscience, Uniformed Services University, Bethesda, MD 20814, USA; (S.Y.K.); (H.F.S.)
- Department of Psychiatry, F. E. Hébert School of Medicine, Uniformed Services University, Bethesda, MD 20814, USA
- Correspondence: ; Tel.: +1-301-295-2682
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[Ketamine Augmented Psychotherapy (KAP) in mood disorder: User guide]. Encephale 2021; 48:304-312. [PMID: 34876279 DOI: 10.1016/j.encep.2021.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/30/2021] [Accepted: 08/20/2021] [Indexed: 01/02/2023]
Abstract
Ketamine, a non-competitive NMDA receptor antagonist, is used as a fast-acting antidepressant therapy in depressive disorders. This treatment provokes dissociative effects associating derealization and depersonalization, and a synaptogenic signaling cascade promoting brain plasticity. Despite several preliminary studies suggesting the usefulness of its combination with psychotherapy, administration of ketamine isn't generally combined with per- and post-infusion psychotherapy protocols in its clinical antidepressant use. However, the phenomenology of psychodysleptic experiences and the synaptogenic effect could potentiate cognitive and behavioral therapies (CBT). In this article, we purpose a practical protocol to Ketamine Augmented Psychotherapy (KAP) synthesizing contemporary data from the literature and our clinical experience. We detail proposals for clinical practice, and propose four important steps for the use of a psychodysleptic molecule for antidepressant purposes: preparation, administration, integration, and prolongation. Finally, we discuss the limits and prospects of this combination in the management of mood disorders.
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8
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Bottemanne H, Arnould A. Ketamine Augmentation of Exposure Response Prevention Therapy for Obsessive-compulsive Disorder. INNOVATIONS IN CLINICAL NEUROSCIENCE 2021; 18:9-11. [PMID: 35096475 PMCID: PMC8794478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Obsessive-compulsive disorder (OCD) is a disabling disease characterized by intrusive thoughts, with compulsions performed to lessen distress. Many patients with OCD do not respond to first-line intervention, such as serotonin reuptake inhibitors (SRIs) and exposure and response prevention (ERP) therapy. Previous studies have focused on the use of ketamine, a nonselective N-methyl D-aspartate receptor (NMDAR) antagonist, for treatment-resistant OCD. Research has shown that ketamine modulates NMDARs and gamma-aminobutyric acid receptors (GABAR), which are major pathways for contingency-learning, belief updating, and extinction learning. Here, we propose an augmented psychotherapy (AP) protocol combining ERP intervention with administration of ketamine. We describe the theory that NMDAR modulation might directly promote the therapeutic mechanisms involved in exposure and discuss the possibility that ketamine plasticity enhancement might potentiate extinction-based psychotherapy in the treatment of OCD.
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Affiliation(s)
- Hugo Bottemanne
- Dr. Bottemanne and Ms. Arnould are with Sorbonne University, Paris Brain Institute-Institut du Cerveau (ICM), and Department of Psychiatry (Pitié-Salpêtrière Hospital, APHP) in Paris, France
| | - Alice Arnould
- Dr. Bottemanne and Ms. Arnould are with Sorbonne University, Paris Brain Institute-Institut du Cerveau (ICM), and Department of Psychiatry (Pitié-Salpêtrière Hospital, APHP) in Paris, France
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9
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Lyndon S, Corlett P. Hallucinations in posttraumatic stress disorder: Insights from predictive coding. JOURNAL OF ABNORMAL PSYCHOLOGY 2020; 129:534-543. [PMID: 32437205 PMCID: PMC10658640 DOI: 10.1037/abn0000531] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Although hallucinations are not one of the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) criteria for posttraumatic stress disorder (PTSD), they are increasingly documented in PTSD. They are noted in the absence of clear delusions, formal thought disorganization, disorganized speech, or behavior, ruling out a comorbid psychotic disorder like schizophrenia as a better explanation for these hallucinations. Hallucinations in both PTSD and schizophrenia share phenomenological features. We propose that hallucinations in PTSD, like those in schizophrenia, might be explained in terms of aberrant predictive coding, specifically the misapplication of strong prior beliefs that vitiate perceptual inference. This approach highlights the broader relationship between trauma and psychosis. Under predictive coding, the nervous system organizes past sensory data into an internal model of the world. Under stress, the brain prioritizes speed over accurate encoding. However, memories for traumatic experiences are typically strongly consolidated, to avoid similar experiences in future. In PTSD, this could lead to a world model comprised of inaccurate but overly precise prior beliefs, that can be triggered by stimuli tangentially related to the index trauma, resulting in hallucinations. Crucially, this evidence accumulation depends upon the relative precision of prior beliefs and sensory evidence (supplied in the form of prediction errors). Our basic argument is that stressful situations induce belief updating, in terms of precise prior beliefs, that are difficult to undo. These unduly precise, trauma-related beliefs then constitute perceptual hypotheses, memories, or narratives that bias subsequent experience. This prior bias may be so severe that sensory evidence is effectively ignored; that is, treated as very imprecise, in relation to prior beliefs. Such an account may lead to cognitive therapies for hallucinations aimed at strong prior beliefs, and the exciting prospect of combining such therapies with drugs that modulate neuroplasticity and enhance the adaptive consolidation of more appropriate priors. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
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Affiliation(s)
- S. Lyndon
- Yale University, Department of Psychiatry, Connecticut Mental Health Center, 34 Park Street, New Haven, CT, USA, 06511
| | - P.R. Corlett
- Yale University, Department of Psychiatry, Connecticut Mental Health Center, 34 Park Street, New Haven, CT, USA, 06511
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10
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Radford KD, Spencer HF, Zhang M, Berman RY, Girasek QL, Choi KH. Association between intravenous ketamine-induced stress hormone levels and long-term fear memory renewal in Sprague-Dawley rats. Behav Brain Res 2019; 378:112259. [PMID: 31560919 DOI: 10.1016/j.bbr.2019.112259] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 01/02/2023]
Abstract
Ketamine is a multimodal dissociative anesthetic and analgesic that is widely used after traumatic injury. We previously reported that an analgesic dose of intravenous (IV) ketamine infusion (10 mg/kg, 2-h) after fear conditioning enhanced short-term fear memory in rats. Here, we investigated the effects of the same dose of an IV ketamine infusion on plasma stress hormone levels and long-term fear memory in rats. Adult male Sprague-Dawley rats (9-week-old with an average weight of 308 g upon arrival) received a ketamine infusion (0 or 10 mg/kg, 2-h) immediately after auditory fear conditioning (three auditory tone and footshock [0.6 mA, 1-s] pairings) on Day 0. After the infusion, a blood sample was collected from a jugular vein catheter for corticosterone and progesterone assays, and each animal was tested on tail flick to measure thermal antinociception. One week later, animals were tested on fear extinction acquisition (Day 7), fear extinction retrieval (Day 8), and fear renewal (Day 9). The IV ketamine infusion, compared to the saline infusion, reduced locomotor activity (sedation), increased tail flick latency (antinociception), and elevated plasma corticosterone and progesterone levels. The ketamine infusion did not alter long-term fear memory extinction or fear renewal. However, elevated corticosterone and progesterone levels resulting from the ketamine infusion were correlated with sedation, antinociception, and long-term fear memory renewal. These results suggest that individual differences in sensitivity to acute ketamine may predict vulnerability to develop fear-related disorders.
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Affiliation(s)
- Kennett D Radford
- Daniel K. Inouye Graduate School of Nursing, Uniformed Services University, Bethesda, MD, 20814, USA
| | - Haley F Spencer
- Program in Neuroscience, Uniformed Services University, Bethesda, MD 20814, USA
| | - Michael Zhang
- Department of Psychiatry, Uniformed Services University, Bethesda, MD, 20814, USA; Center for the Study of Traumatic Stress, Uniformed Services University, Bethesda, MD, 20814, USA
| | - Rina Y Berman
- Daniel K. Inouye Graduate School of Nursing, Uniformed Services University, Bethesda, MD, 20814, USA; Department of Psychiatry, Uniformed Services University, Bethesda, MD, 20814, USA
| | - Quinn L Girasek
- Department of Psychiatry, Uniformed Services University, Bethesda, MD, 20814, USA
| | - Kwang H Choi
- Daniel K. Inouye Graduate School of Nursing, Uniformed Services University, Bethesda, MD, 20814, USA; Program in Neuroscience, Uniformed Services University, Bethesda, MD 20814, USA; Department of Psychiatry, Uniformed Services University, Bethesda, MD, 20814, USA; Center for the Study of Traumatic Stress, Uniformed Services University, Bethesda, MD, 20814, USA.
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11
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Counterconditioning following memory retrieval diminishes the reinstatement of appetitive memories in humans. Sci Rep 2019; 9:9213. [PMID: 31239475 PMCID: PMC6592881 DOI: 10.1038/s41598-019-45492-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 06/04/2019] [Indexed: 11/08/2022] Open
Abstract
Appetitive memories play a crucial role in learning and behavior, but under certain circumstances, such memories become maladaptive and play a vital role in addiction and other psychopathologies. Recent scientific research has demonstrated that memories can be modified following their reactivation through memory retrieval in a process termed memory reconsolidation. Several nonpharmacological behavioral manipulations yielded mixed results in their capacity to alter maladaptive memories in humans. Here, we aimed to translate the promising findings observed in rodents to humans. We constructed a novel three-day procedure using aversive counterconditioning to alter appetitive memories after short memory retrieval. On the first day, we used appetitive conditioning to form appetitive memories. On the second day, we retrieved these appetitive memories in one group (Retrieval group) but not in a second group. Subsequently, all participants underwent counterconditioning. On the third day, we attempted to reinstate the appetitive memories from day one. We observed a significant reduction in the reinstatement of the original appetitive memory when counterconditioning was induced following memory retrieval. Here, we provide a novel human paradigm that models several memory processes and demonstrate memory attenuation when counterconditioned after its retrieval. This paradigm can be used to study complex appetitive memory dynamics, e.g., memory reconsolidation and its underlying brain mechanisms.
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12
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Radford KD, Park TY, Jaiswal S, Pan H, Knutsen A, Zhang M, Driscoll M, Osborne-Smith LA, Dardzinski BJ, Choi KH. Enhanced fear memories and brain glucose metabolism ( 18F-FDG-PET) following sub-anesthetic intravenous ketamine infusion in Sprague-Dawley rats. Transl Psychiatry 2018; 8:263. [PMID: 30504810 PMCID: PMC6269482 DOI: 10.1038/s41398-018-0310-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 09/25/2018] [Accepted: 11/08/2018] [Indexed: 12/18/2022] Open
Abstract
Ketamine is a multimodal dissociative anesthetic, which provides powerful analgesia for victims with traumatic injury. However, the impact of ketamine administration in the peri-trauma period on the development of post-traumatic stress disorder (PTSD) remains controversial. Moreover, there is a major gap between preclinical and clinical studies because they utilize different doses and routes of ketamine administration. Here, we investigated the effects of sub-anesthetic doses of intravenous (IV) ketamine infusion on fear memory and brain glucose metabolism (BGluM) in rats. Male Sprague-Dawley rats received an IV ketamine infusion (0, 2, 10, and 20 mg/kg, 2 h) or an intraperitoneal (IP) injection (0 and 10 mg/kg) following an auditory fear conditioning (3 pairings of tone and foot shock [0.6 mA, 1 s]) on day 0. Fear memory retrieval, fear extinction, and fear recall were tested on days 2, 3, and 4, respectively. The effects of IV ketamine infusion (0 and 10 mg/kg) on BGluM were measured using 18F-fluoro-deoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT). The IV ketamine infusion dose-dependently enhanced fear memory retrieval, delayed fear extinction, and increased fear recall in rats. The IV ketamine (10 mg/kg) increased BGluM in the hippocampus, amygdala, and hypothalamus, while decreasing it in the cerebellum. On the contrary, a single ketamine injection (10 mg/kg, IP) after fear conditioning facilitated fear memory extinction in rats. The current findings suggest that ketamine may produce differential effects on fear memory depending on the route and duration of ketamine administration.
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Affiliation(s)
- Kennett D. Radford
- 0000 0001 0421 5525grid.265436.0Daniel K. Inouye Graduate School of Nursing, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Thomas Y. Park
- 0000 0001 0421 5525grid.265436.0Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Shalini Jaiswal
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Hongna Pan
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Andrew Knutsen
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Michael Zhang
- 0000 0001 0421 5525grid.265436.0Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Mercedes Driscoll
- 0000 0001 0560 6544grid.414467.4National Capital Consortium Psychiatry Residency Program, Walter Reed National Military Medical Center, Bethesda, MD 20814 USA
| | - Lisa A. Osborne-Smith
- 0000 0000 9758 5690grid.5288.7Nurse Anesthesia Program, Oregon Health and Science University, Portland, OR 97239 USA
| | - Bernard J. Dardzinski
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Department of Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Kwang H. Choi
- 0000 0001 0421 5525grid.265436.0Daniel K. Inouye Graduate School of Nursing, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
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13
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Sterzer P, Adams RA, Fletcher P, Frith C, Lawrie SM, Muckli L, Petrovic P, Uhlhaas P, Voss M, Corlett PR. The Predictive Coding Account of Psychosis. Biol Psychiatry 2018; 84:634-643. [PMID: 30007575 PMCID: PMC6169400 DOI: 10.1016/j.biopsych.2018.05.015] [Citation(s) in RCA: 386] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 01/12/2023]
Abstract
Fueled by developments in computational neuroscience, there has been increasing interest in the underlying neurocomputational mechanisms of psychosis. One successful approach involves predictive coding and Bayesian inference. Here, inferences regarding the current state of the world are made by combining prior beliefs with incoming sensory signals. Mismatches between prior beliefs and incoming signals constitute prediction errors that drive new learning. Psychosis has been suggested to result from a decreased precision in the encoding of prior beliefs relative to the sensory data, thereby garnering maladaptive inferences. Here, we review the current evidence for aberrant predictive coding and discuss challenges for this canonical predictive coding account of psychosis. For example, hallucinations and delusions may relate to distinct alterations in predictive coding, despite their common co-occurrence. More broadly, some studies implicate weakened prior beliefs in psychosis, and others find stronger priors. These challenges might be answered with a more nuanced view of predictive coding. Different priors may be specified for different sensory modalities and their integration, and deficits in each modality need not be uniform. Furthermore, hierarchical organization may be critical. Altered processes at lower levels of a hierarchy need not be linearly related to processes at higher levels (and vice versa). Finally, canonical theories do not highlight active inference-the process through which the effects of our actions on our sensations are anticipated and minimized. It is possible that conflicting findings might be reconciled by considering these complexities, portending a framework for psychosis more equipped to deal with its many manifestations.
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Affiliation(s)
- Philipp Sterzer
- Department of Psychiatry, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rick A Adams
- Division of Psychiatry, University College London, London, United Kingdom
| | - Paul Fletcher
- Department of Psychiatry, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom; Wellcome-MRC Behavioral and Clinical Neuroscience Institute, Cambridge and Peterborough Foundation Trust, Cambridge, United Kingdom
| | - Chris Frith
- Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom
| | - Stephen M Lawrie
- Center for Clinical and Brain Sciences, Division of Psychiatry, Royal Edinburgh Hospital, University of Edinburgh, Edinburgh, United Kingdom
| | - Lars Muckli
- Centre for Cognitive Neuroimaging, Institute of Neuroscience & Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Predrag Petrovic
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Peter Uhlhaas
- Centre for Cognitive Neuroimaging, Institute of Neuroscience & Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Martin Voss
- Department of Psychiatry and Psychotherapy, Charité University Medicine and St. Hedwig Hospital, Berlin Center for Advanced Neuroimaging, Humboldt University Berlin, Berlin, Germany
| | - Philip R Corlett
- Department of Psychiatry, Yale University, New Haven, Connecticut.
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14
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Periodical reactivation under the effect of caffeine attenuates fear memory expression in rats. Sci Rep 2018; 8:7260. [PMID: 29740084 PMCID: PMC5940846 DOI: 10.1038/s41598-018-25648-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 04/20/2018] [Indexed: 11/17/2022] Open
Abstract
In the last decade, several studies have shown that fear memories can be attenuated by interfering with reconsolidation. However, most of the pharmacological agents used in preclinical studies cannot be administered to humans. Caffeine is one of the world’s most popular psychoactive drugs and its effects on cognitive and mood states are well documented. Nevertheless, the influence of caffeine administration on fear memory processing is not as clear. We employed contextual fear conditioning in rats and acute caffeine administration under a standard memory reconsolidation protocol or periodical memory reactivation. Additionally, potential rewarding/aversion and anxiety effects induced by caffeine were evaluated by conditioning place preference or open field, respectively. Caffeine administration was able to attenuate weak fear memories in a standard memory reconsolidation protocol; however, periodical memory reactivation under caffeine effect was necessary to attenuate strong and remote memories. Moreover, caffeine promoted conditioned place preference and anxiolytic-like behavior, suggesting that caffeine weakens the initial learning during reactivation through counterconditioning mechanisms. Thus, our study shows that rewarding and anxiolytic effects of caffeine during fear reactivation can change the emotional valence of fear memory. It brings a new promising pharmacological approach based on drugs widely used such as caffeine to treat fear-related disorders.
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15
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Effects of systemic glutamatergic manipulations on conditioned eyeblink responses and hyperarousal in a rabbit model of post-traumatic stress disorder. Behav Pharmacol 2018; 28:565-577. [PMID: 28799954 DOI: 10.1097/fbp.0000000000000333] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Glutamatergic dysfunction is implicated in many neuropsychiatric conditions, including post-traumatic stress disorder (PTSD). Glutamate antagonists have shown some utility in treating PTSD symptoms, whereas glutamate agonists may facilitate cognitive behavioral therapy outcomes. We have developed an animal model of PTSD, based on conditioning of the rabbit's eyeblink response, that addresses two key features: conditioned responses (CRs) to cues associated with an aversive event and a form of conditioned hyperarousal referred to as conditioning-specific reflex modification (CRM). The optimal treatment to reduce both CRs and CRM is unpaired extinction. The goals of the study were to examine whether treatment with the N-methyl-D-aspartate glutamate receptor antagonist ketamine could reduce CRs and CRM, and whether the N-methyl-D-aspartate agonist D-cycloserine combined with unpaired extinction treatment could enhance the extinction of both. Administration of a single dose of subanesthetic ketamine had no significant immediate or delayed effect on CRs or CRM. Combining D-cycloserine with a single day of unpaired extinction facilitated extinction of CRs in the short term while having no impact on CRM. These results caution that treatments may improve one aspect of the PTSD symptomology while having no significant effects on other symptoms, stressing the importance of a multiple-treatment approach to PTSD and of animal models that address multiple symptoms.
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16
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Abstract
Ketamine, principally an antagonist of N-methyl-ᴅ-aspartate receptors, induces schizophrenia-like symptoms in adult humans, warranting its use in the investigation of psychosis-related phenotypes in animal models. Genomic studies further implicate N-methyl-ᴅ-aspartate receptor-mediated processes in schizophrenia pathology, together with more broadly-defined synaptic plasticity and associative learning processes. Strong pathophysiological links have been demonstrated between fear learning and psychiatric disorders such as schizophrenia. To further investigate the impact of ketamine on associative fear learning, we studied the effects of pre- and post-training ketamine on the consolidation and extinction of contextual fear memory in rats. Administration of 25 mg/kg ketamine prior to fear conditioning did not affect consolidation when potentially confounding effects of state dependency were controlled for. Pre-training ketamine (25 mg/kg) impaired the extinction of the conditioned fear response, which was mirrored with the use of a lower dose (8 mg/kg). Post-training ketamine (25 mg/kg) had no effect on the consolidation or extinction of conditioned fear. These observations implicate processes relating to the extinction of contextual fear memory in the manifestation of ketamine-induced phenotypes, and are consistent with existing hypotheses surrounding abnormal associative learning in schizophrenia.
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Affiliation(s)
- Nicholas E Clifton
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK
| | - Kerrie L Thomas
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK
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17
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Psychedelics and reconsolidation of traumatic and appetitive maladaptive memories: focus on cannabinoids and ketamine. Psychopharmacology (Berl) 2018; 235:433-445. [PMID: 29178010 DOI: 10.1007/s00213-017-4793-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 11/14/2017] [Indexed: 12/22/2022]
Abstract
RATIONALE Clinical data with 3,4-methylenedioxymethamphetamine (MDMA) in post-traumatic stress disorder (PTSD) patients recently stimulated interest on the potential therapeutic use of psychedelics in disorders characterized by maladaptive memories, including substance use disorders (SUD). The rationale for the use of MDMA in PTSD and SUD is being extended to a broader beneficial "psychedelic effect," which is supporting further clinical investigations, in spite of the lack of mechanistic hypothesis. Considering that the retrieval of emotional memories reactivates specific brain mechanisms vulnerable to inhibition, interference, or strengthening (i.e., the reconsolidation process), it was proposed that the ability to retrieve and change these maladaptive memories might be a novel intervention for PTSD and SUD. The mechanisms underlying MDMA effects indicate memory reconsolidation modulation as a hypothetical process underlying its efficacy. OBJECTIVE Mechanistic and clinical studies with other two classes of psychedelic substances, namely cannabinoids and ketamine, are providing data in support of a potential use in PTSD and SUD based on the modulation of traumatic and appetitive memory reconsolidation, respectively. Here, we review preclinical and clinical data on cannabinoids and ketamine effects on biobehavioral processes related to the reconsolidation of maladaptive memories. RESULTS We report the findings supporting (or not) the working hypothesis linking the potential therapeutic effect of these substances to the underlying reconsolidation process. We also proposed possible approaches for testing the use of these two classes of drugs within the current paradigm of reconsolidation memory inhibition. CONCLUSIONS Metaplasticity may be the process in common between cannabinoids and ketamine/ketamine-like substance effects on the mediation and potential manipulation of maladaptive memories.
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18
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Ivan Ezquerra-Romano I, Lawn W, Krupitsky E, Morgan CJA. Ketamine for the treatment of addiction: Evidence and potential mechanisms. Neuropharmacology 2018; 142:72-82. [PMID: 29339294 DOI: 10.1016/j.neuropharm.2018.01.017] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 01/08/2018] [Accepted: 01/11/2018] [Indexed: 12/14/2022]
Abstract
Ketamine is a dissociative anaesthetic drug which acts on the central nervous system chiefly through antagonism of the n-methyl-d-aspartate (NMDA) receptor. Recently, ketamine has attracted attention as a rapid-acting anti-depressant but other studies have also reported its efficacy in reducing problematic alcohol and drug use. This review explores the preclinical and clinical research into ketamine's ability to treat addiction. Despite methodological limitations and the relative infancy of the field, results thus far are promising. Ketamine has been shown to effectively prolong abstinence from alcohol and heroin in detoxified alcoholics and heroin dependent individuals, respectively. Moreover, ketamine reduced craving for and self-administration of cocaine in non-treatment seeking cocaine users. However, further randomised controlled trials are urgently needed to confirm ketamine's efficacy. Possible mechanisms by which ketamine may work within addiction include: enhancement of neuroplasticity and neurogenesis, disruption of relevant functional neural networks, treating depressive symptoms, blocking reconsolidation of drug-related memories, provoking mystical experiences and enhancing psychological therapy efficacy. Identifying the mechanisms by which ketamine exerts its therapeutic effects in addiction, from the many possible candidates, is crucial for advancing this treatment and may have broader implications understanding other psychedelic therapies. In conclusion, ketamine shows great promise as a treatment for various addictions, but well-controlled research is urgently needed. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.
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Affiliation(s)
- I Ivan Ezquerra-Romano
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
| | - W Lawn
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, UK
| | - E Krupitsky
- St.-Petersburg Pavlov State Medical University and Bekhterev Research Psychoneurological Institute, St. Petersburg, Russia
| | - C J A Morgan
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, UK; Psychopharmacology and Addiction Research Centre, University of Exeter, Exeter, UK.
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19
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Fattore L, Piva A, Zanda MT, Fumagalli G, Chiamulera C. Psychedelics and reconsolidation of traumatic and appetitive maladaptive memories: focus on cannabinoids and ketamine. Psychopharmacology (Berl) 2017. [PMID: 29178010 DOI: 10.1007/s00213-017-4793-4.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
RATIONALE Clinical data with 3,4-methylenedioxymethamphetamine (MDMA) in post-traumatic stress disorder (PTSD) patients recently stimulated interest on the potential therapeutic use of psychedelics in disorders characterized by maladaptive memories, including substance use disorders (SUD). The rationale for the use of MDMA in PTSD and SUD is being extended to a broader beneficial "psychedelic effect," which is supporting further clinical investigations, in spite of the lack of mechanistic hypothesis. Considering that the retrieval of emotional memories reactivates specific brain mechanisms vulnerable to inhibition, interference, or strengthening (i.e., the reconsolidation process), it was proposed that the ability to retrieve and change these maladaptive memories might be a novel intervention for PTSD and SUD. The mechanisms underlying MDMA effects indicate memory reconsolidation modulation as a hypothetical process underlying its efficacy. OBJECTIVE Mechanistic and clinical studies with other two classes of psychedelic substances, namely cannabinoids and ketamine, are providing data in support of a potential use in PTSD and SUD based on the modulation of traumatic and appetitive memory reconsolidation, respectively. Here, we review preclinical and clinical data on cannabinoids and ketamine effects on biobehavioral processes related to the reconsolidation of maladaptive memories. RESULTS We report the findings supporting (or not) the working hypothesis linking the potential therapeutic effect of these substances to the underlying reconsolidation process. We also proposed possible approaches for testing the use of these two classes of drugs within the current paradigm of reconsolidation memory inhibition. CONCLUSIONS Metaplasticity may be the process in common between cannabinoids and ketamine/ketamine-like substance effects on the mediation and potential manipulation of maladaptive memories.
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Affiliation(s)
- Liana Fattore
- National Research Council of Italy, Institute of Neuroscience-Cagliari, Cagliari, Italy
| | - Alessandro Piva
- Sezione Farmacologia, Dipt. Diagnostica e Sanità Pubblica, Università degli Studi di Verona, Policlinico Borgo Roma, P.le Scuro 10, 37134, Verona, Italy
| | - Mary Tresa Zanda
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cittadella Universitaria di Monserrato, SP 8, Km 0.700, 09042, Monserrato, Italy
| | - Guido Fumagalli
- Sezione Farmacologia, Dipt. Diagnostica e Sanità Pubblica, Università degli Studi di Verona, Policlinico Borgo Roma, P.le Scuro 10, 37134, Verona, Italy
| | - Cristiano Chiamulera
- Sezione Farmacologia, Dipt. Diagnostica e Sanità Pubblica, Università degli Studi di Verona, Policlinico Borgo Roma, P.le Scuro 10, 37134, Verona, Italy.
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20
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Comprehensive review: Computational modelling of schizophrenia. Neurosci Biobehav Rev 2017; 83:631-646. [PMID: 28867653 DOI: 10.1016/j.neubiorev.2017.08.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 07/08/2017] [Accepted: 08/30/2017] [Indexed: 12/21/2022]
Abstract
Computational modelling has been used to address: (1) the variety of symptoms observed in schizophrenia using abstract models of behavior (e.g. Bayesian models - top-down descriptive models of psychopathology); (2) the causes of these symptoms using biologically realistic models involving abnormal neuromodulation and/or receptor imbalance (e.g. connectionist and neural networks - bottom-up realistic models of neural processes). These different levels of analysis have been used to answer different questions (i.e. understanding behavioral vs. neurobiological anomalies) about the nature of the disorder. As such, these computational studies have mostly supported diverging hypotheses of schizophrenia's pathophysiology, resulting in a literature that is not always expanding coherently. Some of these hypotheses are however ripe for revision using novel empirical evidence. Here we present a review that first synthesizes the literature of computational modelling for schizophrenia and psychotic symptoms into categories supporting the dopamine, glutamate, GABA, dysconnection and Bayesian inference hypotheses respectively. Secondly, we compare model predictions against the accumulated empirical evidence and finally we identify specific hypotheses that have been left relatively under-investigated.
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21
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The role of glucocorticoids in emotional memory reconsolidation. Neurobiol Learn Mem 2017; 142:126-134. [DOI: 10.1016/j.nlm.2016.11.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 01/13/2023]
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22
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Li Q, Shi L, Lu G, Yu HL, Yeung FK, Wong NK, Sun L, Liu K, Yew D, Pan F, Wang DF, Sham PC. Chronic Ketamine Exposure Causes White Matter Microstructural Abnormalities in Adolescent Cynomolgus Monkeys. Front Neurosci 2017; 11:285. [PMID: 28579941 PMCID: PMC5437169 DOI: 10.3389/fnins.2017.00285] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/02/2017] [Indexed: 01/05/2023] Open
Abstract
Acute and repeated exposures to ketamine mimic aspects of positive, negative, and cognitive symptoms of schizophrenia in humans. Recent studies by our group and others have shown that chronicity of ketamine use may be a key element for establishing a more valid model of cognitive symptoms of schizophrenia. However, current understanding on the long-term consequences of ketamine exposure on brain circuits has remained incomplete, particularly with regard to microstructural changes of white matter tracts that underpin the neuropathology of schizophrenia. Thus, the present study aimed to expand on previous investigations by examining causal effects of repeated ketamine exposure on white matter integrity in a non-human primate model. Ketamine or saline (control) was administered intravenously for 3 months to male adolescent cynomolgus monkeys (n = 5/group). Diffusion tensor imaging (DTI) experiments were performed and tract-based spatial statistics (TBSS) was used for data analysis. Fractional anisotropy (FA) was quantified across the whole brain. Profoundly reduced FA on the right side of sagittal striatum, posterior thalamic radiation (PTR), retrolenticular limb of the internal capsule (RLIC) and superior longitudinal fasciculus (SLF), and on the left side of PTR, middle temporal gyrus and inferior frontal gyrus were observed in the ketamine group compared to controls. Diminished white matter integrity found in either fronto-thalamo-temporal or striato-thalamic connections with tracts including the SLF, PTR, and RLIC lends support to similar findings from DTI studies on schizophrenia in humans. This study suggests that chronic ketamine exposure is a useful pharmacological paradigm that might provide translational insights into the pathophysiology and treatment of schizophrenia.
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Affiliation(s)
- Qi Li
- Department of Psychiatry, The University of Hong KongHong Kong, Hong Kong.,State Key Laboratory for Cognitive and Brain Sciences, The University of Hong KongHong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation (HKU-SIRI), The University of Hong KongHong Kong, Hong Kong
| | - Lin Shi
- Department of Medicine and Therapeutics, Chinese University of Hong KongHong Kong, Hong Kong.,Chow Yuk Ho Center of Innovative Technology for Medicine, Chinese University of Hong KongHong Kong, Hong Kong
| | - Gang Lu
- School of Biomedical Sciences, Chinese University of Hong KongHong Kong, Hong Kong
| | - Hong-Luan Yu
- Department of Psychology, Qilu Hospital of Shandong UniversityJinan, China
| | - Fu-Ki Yeung
- Research Center for Medical Image Computing, Department of Imaging and Interventional Radiology, Chinese University of Hong KongHong Kong, Hong Kong
| | - Nai-Kei Wong
- Chemical Biology Laboratory for Infectious Diseases, Shenzhen Institute of Hepatology, The Third People's Hospital of ShenzhenShenzhen, China
| | - Lin Sun
- Department of Psychology, Weifang Medical UniversityWeifang, China
| | - Kai Liu
- Research Center for Medical Image Computing, Department of Imaging and Interventional Radiology, Chinese University of Hong KongHong Kong, Hong Kong
| | - David Yew
- School of Chinese Medicine, Chinese University of Hong KongHong Kong, Hong Kong
| | - Fang Pan
- Department of Medical Psychology, Shandong University School of MedicineJinan, China
| | - De-Feng Wang
- Research Center for Medical Image Computing, Department of Imaging and Interventional Radiology, Chinese University of Hong KongHong Kong, Hong Kong
| | - Pak C Sham
- Department of Psychiatry, The University of Hong KongHong Kong, Hong Kong.,State Key Laboratory for Cognitive and Brain Sciences, The University of Hong KongHong Kong, Hong Kong.,Genome Research Centre, The University of Hong KongHong Kong, Hong Kong
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Feeney EJ, Groman SM, Taylor JR, Corlett PR. Explaining Delusions: Reducing Uncertainty Through Basic and Computational Neuroscience. Schizophr Bull 2017; 43:263-272. [PMID: 28177090 PMCID: PMC5605246 DOI: 10.1093/schbul/sbw194] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Delusions, the fixed false beliefs characteristic of psychotic illness, have long defied understanding despite their response to pharmacological treatments (e.g., D2 receptor antagonists). However, it can be challenging to discern what makes beliefs delusional compared with other unusual or erroneous beliefs. We suggest mapping the putative biology to clinical phenomenology with a cognitive psychology of belief, culminating in a teleological approach to beliefs and brain function supported by animal and computational models. We argue that organisms strive to minimize uncertainty about their future states by forming and maintaining a set of beliefs (about the organism and the world) that are robust, but flexible. If uncertainty is generated endogenously, beliefs begin to depart from consensual reality and can manifest into delusions. Central to this scheme is the notion that formal associative learning theory can provide an explanation for the development and persistence of delusions. Beliefs, in animals and humans, may be associations between representations (e.g., of cause and effect) that are formed by minimizing uncertainty via new learning and attentional allocation. Animal research has equipped us with a deep mechanistic basis of these processes, which is now being applied to delusions. This work offers the exciting possibility of completing revolutions of translation, from the bedside to the bench and back again. The more we learn about animal beliefs, the more we may be able to apply to human beliefs and their aberrations, enabling a deeper mechanistic understanding.
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Affiliation(s)
- Erin J Feeney
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Stephanie M Groman
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
| | - Jane R Taylor
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
| | - Philip R Corlett
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
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24
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Reconsolidation and psychopathology: Moving towards reconsolidation-based treatments. Neurobiol Learn Mem 2016; 142:162-171. [PMID: 27838441 DOI: 10.1016/j.nlm.2016.11.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/19/2016] [Accepted: 11/04/2016] [Indexed: 01/14/2023]
Abstract
Interfering with memory reconsolidation has valuable potential to be used as a treatment for maladaptive memories and psychiatric disorders. Numerous studies suggest that reconsolidation-based therapies may benefit psychiatric populations, but much remains unanswered. After reviewing the literature in clinical and healthy human populations, we discuss some of the major limitations to reconsolidation studies and clinical application. Finally, we provide recommendations for developing improved reconsolidation-based treatments, namely exploiting known boundary conditions and focusing on a novel unconditioned stimulus-retrieval paradigm.
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25
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Abstract
In 2007, we proposed an explanation of delusion formation as aberrant prediction error-driven associative learning. Further, we argued that the NMDA receptor antagonist ketamine provided a good model for this process. Subsequently, we validated the model in patients with psychosis, relating aberrant prediction error signals to delusion severity. During the ensuing period, we have developed these ideas, drawing on the simple principle that brains build a model of the world and refine it by minimising prediction errors, as well as using it to guide perceptual inferences. While previously we focused on the prediction error signal per se, an updated view takes into account its precision, as well as the precision of prior expectations. With this expanded perspective, we see several possible routes to psychotic symptoms - which may explain the heterogeneity of psychotic illness, as well as the fact that other drugs, with different pharmacological actions, can produce psychotomimetic effects. In this article, we review the basic principles of this model and highlight specific ways in which prediction errors can be perturbed, in particular considering the reliability and uncertainty of predictions. The expanded model explains hallucinations as perturbations of the uncertainty mediated balance between expectation and prediction error. Here, expectations dominate and create perceptions by suppressing or ignoring actual inputs. Negative symptoms may arise due to poor reliability of predictions in service of action. By mapping from biology to belief and perception, the account proffers new explanations of psychosis. However, challenges remain. We attempt to address some of these concerns and suggest future directions, incorporating other symptoms into the model, building towards better understanding of psychosis.
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Affiliation(s)
| | | | - Paul C Fletcher
- Department of Psychiatry, University of Cambridge, Cambridge, UK .,Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK
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26
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Modification of Fear Memory by Pharmacological and Behavioural Interventions during Reconsolidation. PLoS One 2016; 11:e0161044. [PMID: 27537364 PMCID: PMC4990323 DOI: 10.1371/journal.pone.0161044] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 06/23/2016] [Indexed: 11/19/2022] Open
Abstract
Background Dysfunctional fear responses play a central role in many mental disorders. New insights in learning and memory suggest that pharmacological and behavioural interventions during the reconsolidation of reactivated fear memories may increase the efficacy of therapeutic interventions. It has been proposed that interventions applied during reconsolidation may modify the original fear memory, and thus prevent the spontaneous recovery and reinstatement of the fear response. Methods We investigated whether pharmacological (propranolol) and behavioural (reappraisal, multisensory stimulation) interventions reduce fear memory, and prevent reinstatement of fear in comparison to a placebo control group. Eighty healthy female subjects underwent a differential fear conditioning procedure with three stimuli (CS). Two of these (CS+) were paired with an electric shock on day 1. On day 2, 20 subjects were pseudo-randomly assigned to either the propranolol or placebo condition, or underwent one of the two behavioural interventions after one of the two CS+ was reactivated. On day 3, all subjects underwent an extinction phase, followed by a reinstatement test. Dependent variables were US expectancy ratings, fear-potentiated startle, and skin conductance response. Results Differential fear responses to the reactivated and non-reactivated CS+ were observed only in the propranolol condition. Here, the non-reactivated CS+ evoked stronger fear-potentiated startle-responses compared to the placebo group. None of the interventions prevented the return of the extinguished fear response after re-exposure to the unconditioned stimulus. Conclusions Our data are in line with an increasing body of research stating that the occurrence of reconsolidation may be constrained by boundary conditions such as subtle differences in experimental manipulations and instructions. In conclusion, our findings do not support a beneficial effect in using reconsolidation processes to enhance effects of psychotherapeutic interventions. This implies that more research is required before therapeutic interventions may benefit from a combination with reconsolidation processes.
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27
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Duclot F, Perez-Taboada I, Wright KN, Kabbaj M. Prediction of individual differences in fear response by novelty seeking, and disruption of contextual fear memory reconsolidation by ketamine. Neuropharmacology 2016; 109:293-305. [PMID: 27343386 DOI: 10.1016/j.neuropharm.2016.06.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/23/2016] [Accepted: 06/21/2016] [Indexed: 01/07/2023]
Abstract
Only a portion of the population exposed to trauma will develop persistent emotional alterations characteristic of posttraumatic stress disorder (PTSD), which illustrates the necessity for identifying vulnerability factors and novel pharmacotherapeutic alternatives. Interestingly, clinical evidence suggests that novelty seeking is a good predictor for vulnerability to the development of excessive and persistent fear. Here, we first tested this hypothesis by analyzing contextual and cued fear responses of rats selected for their high (high responders, HR) or low (low responders, LR) exploration of a novel environment, indicator of novelty seeking. While HR and LR rats exhibited similar sensitivity to the shock and cued fear memory retention, fewer extinction sessions were required in HR than LR animals to reach extinction, indicating faster contextual and cued memory extinction. In a second part, we found an effective disruption of contextual fear reconsolidation by the N-methyl-d-aspartate receptor antagonist ketamine, associated with a down-regulation of early growth response 1 (Egr1) in the hippocampal CA1 area, and up-regulation of brain-derived neurotrophic factor (Bdnf) mRNA levels in the prelimbic and infralimbic cortices. Altogether, these data demonstrate a link between novelty seeking and conditioned fear extinction, and highlight a promising novel role of ketamine in affecting established fear memory.
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Affiliation(s)
- Florian Duclot
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, United States; Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States
| | - Iara Perez-Taboada
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, United States; Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States
| | - Katherine N Wright
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, United States; Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States
| | - Mohamed Kabbaj
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, United States; Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States.
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28
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Stratford A, Brophy L, Castle D, Harvey C, Robertson J, Corlett P, Davidson L, Everall I. Embedding a Recovery Orientation into Neuroscience Research: Involving People with a Lived Experience in Research Activity. Psychiatr Q 2016; 87:75-88. [PMID: 25969424 DOI: 10.1007/s11126-015-9364-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper highlights the importance and value of involving people with a lived experience of mental ill health and recovery in neuroscience research activity. In this era of recovery oriented service delivery, involving people with the lived experience of mental illness in neuroscience research extends beyond their participation as "subjects". The recovery paradigm reconceptualises people with the lived experience of mental ill health as experts by experience. To support this contribution, local policies and procedures, recovery-oriented training for neuroscience researchers, and dialogue about the practical applications of neuroscience research, are required.
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Affiliation(s)
| | - Lisa Brophy
- Mind Australia, Melbourne, Australia. .,The Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - David Castle
- Department of Psychiatry, The University of Melbourne, Melbourne, Australia. .,St Vincent's Health, Melbourne, Australia.
| | - Carol Harvey
- Department of Psychiatry, The University of Melbourne, Melbourne, Australia.
| | - Joanne Robertson
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia.
| | - Philip Corlett
- School of Medicine and Institution for Social and Policy Studies, Yale University, New Haven, USA.
| | - Larry Davidson
- School of Medicine and Institution for Social and Policy Studies, Yale University, New Haven, USA.
| | - Ian Everall
- Department of Psychiatry, The University of Melbourne, Melbourne, Australia.
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29
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Abstract
We reconsider delusions in terms of a "doxastic shear pin", a mechanism that errs so as to prevent the destruction of the machine (brain) and permit continued function (in an attenuated capacity). Delusions may disable flexible (but energetically expensive) inference. With each recall, delusions may be reinforced further and rendered resistant to contradiction. We aim to respond to deficit accounts of delusions - that delusions are only a problem without any benefit - by considering delusion formation and maintenance in terms of predictive coding. We posit that brains conform to a simple computational principle: to minimize prediction error (the mismatch between prior top-down expectation and current bottom-up input) across hierarchies of brain regions and psychological representation. Recent data suggest that delusions may form in the absence of constraining top-down expectations. Then, once formed, they become new priors that motivate other beliefs, perceptions, and actions by providing strong (sometimes overriding) top-down expectation. We argue that delusions form when the shear-pin breaks, permitting continued engagement with an overwhelming world, and ongoing function in the face of paralyzing difficulty. This crucial role should not be ignored when we treat delusions: we need to consider how a person will function in the world without them..
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Affiliation(s)
- S.K. Fineberg
- Yale University, Department of Psychiatry, Ribicoff Research Facility. 34 Park Street, New Haven, CT, USA 06519
| | - P.R. Corlett
- Yale University, Department of Psychiatry, Ribicoff Research Facility. 34 Park Street, New Haven, CT, USA 06519
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30
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Gupta S, Ranganathan M, D'Souza DC. The early identification of psychosis: can lessons be learnt from cardiac stress testing? Psychopharmacology (Berl) 2016; 233:19-37. [PMID: 26566609 PMCID: PMC4703558 DOI: 10.1007/s00213-015-4143-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/31/2015] [Indexed: 12/31/2022]
Abstract
Psychotic disorders including schizophrenia are amongst the most debilitating psychiatric disorders. There is an urgent need to develop methods to identify individuals at risk with greater precision and as early as possible. At present, a prerequisite for a diagnosis of schizophrenia is the occurrence of a psychotic episode. Therefore, attempting to detect schizophrenia on the basis of psychosis is analogous to diagnosing coronary artery disease (CAD) after the occurrence of a myocardial infarction (MI). The introduction of cardiac stress testing (CST) has revolutionized the detection of CAD and the prevention and management of angina and MI. In this paper, we attempt to apply lessons learnt from CST to the early detection of psychosis by proposing the development of an analogous psychosis stress test. We discuss in detail the various parameters of a proposed psychosis stress test including the choice of a suitable psychological or psychopharmacological "stressor," target population, outcome measures, safety of the approach, and the necessary evolution of test to become clinically informative. The history of evolution of CST may guide the development of a similar approach for the detection and management of psychotic disorders. The initial development of a test to unmask latent risk for schizophrenia will require the selection of a suitable and safe stimulus and the development of outcome measures as a prelude to testing in populations with a range of risk to determine predictive value. The use of CST in CAD offers the intriguing possibility that a similar approach may be applied to the detection and management of schizophrenia.
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Affiliation(s)
- Swapnil Gupta
- Psychiatry Service 116A, VA Connecticut Healthcare System, 950 Campbell Avenue, West Haven, CT, 06516, USA
- Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Mohini Ranganathan
- Psychiatry Service 116A, VA Connecticut Healthcare System, 950 Campbell Avenue, West Haven, CT, 06516, USA
- Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Deepak Cyril D'Souza
- Psychiatry Service 116A, VA Connecticut Healthcare System, 950 Campbell Avenue, West Haven, CT, 06516, USA.
- Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA.
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
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31
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Pharmacological and non-pharmacological factors that regulate the acquisition of ketamine self-administration in rats. Psychopharmacology (Berl) 2015; 232:4505-14. [PMID: 26387516 DOI: 10.1007/s00213-015-4077-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/07/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Recreational ketamine use may be modulated by factors such as ketamine infusion patterns, associated conditioned stimuli and spatial-temporal contexts. Our aim was to study the pharmacological and non-pharmacological factors that regulate the acquisition of ketamine use. METHODS In experiment 1, four groups of male rats were trained to self-administer ketamine during nine 1-h daily sessions, under four reinforcement schedules: i) pre-session ketamine priming (Priming-[KET]), ii) conditioned stimulus (CS) paired to the ketamine infusions ([KET + CS]), iii) neither priming nor CS ([KET]), iv) combination of both (Priming-[KET + CS]). In experiment 2, two groups of male rats were trained to self-administer ketamine during nine 1-h daily or weekly sessions, under the Priming-[KET + CS] schedule. Lever pressing was then extinguished by saline substitution for ketamine infusion. Afterwards, ketamine was made available again upon responding under the same schedule. RESULTS The Priming-[KET + CS] schedule of reinforcement showed a significant increase in the number of ketamine reinforcements and a significant discrimination between active vs. inactive levers. The same schedule allowed the establishment of ketamine self-administration on a weekly basis. During the extinction phase, rate of responding significantly dropped in both weekly and daily groups although it was twofold longer in the former, which showed a lack of reacquisition. CONCLUSIONS Both pre-session ketamine priming and a conditioned stimulus paired to the ketamine infusions are required for the acquisition of ketamine self-administration. The longer extinction and the lack of reacquisition in the weekly group could be due to changes in temporal context that might affect the conditioning process.
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32
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Cannon TD. How Schizophrenia Develops: Cognitive and Brain Mechanisms Underlying Onset of Psychosis. Trends Cogn Sci 2015; 19:744-756. [PMID: 26493362 DOI: 10.1016/j.tics.2015.09.009] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 12/12/2022]
Abstract
Identifying cognitive and neural mechanisms involved in the development of schizophrenia requires longitudinal observation of individuals prior to onset. Here recent studies of prodromal individuals who progress to full psychosis are briefly reviewed in relation to models of schizophrenia pathophysiology. Together, this body of work suggests that disruption in brain connectivity, driven primarily by a progressive reduction in dendritic spines on cortical pyramidal neurons, may represent a key triggering mechanism. The earliest disruptions appear to be in circuits involved in referencing experiences according to time, place, and agency, which may result in a failure to recognize particular cognitions as self-generated or to constrain interpretations of the meaning of events based on prior experiences, providing the scaffolding for faulty reality testing.
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Affiliation(s)
- Tyrone D Cannon
- Department of Psychology, Yale University, 2 Hillhouse Avenue, P.O. Box 208205, New Haven, CT 06520, USA.
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33
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Honsberger MJ, Taylor JR, Corlett PR. Memories reactivated under ketamine are subsequently stronger: A potential pre-clinical behavioral model of psychosis. Schizophr Res 2015; 164:227-33. [PMID: 25728834 PMCID: PMC4409515 DOI: 10.1016/j.schres.2015.02.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/05/2015] [Accepted: 02/08/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND Sub-anesthetic doses of the NMDA antagonist ketamine have been shown to model the formation and stability of delusion in human subjects. The latter has been predicted to be due to aberrant prediction error resulting in enhanced destabilization of beliefs. To extend the scope of this model, we investigated the effect of administration of low dose systemic ketamine on memory in a rodent model of memory reconsolidation. METHODS Systemic ketamine was administered either prior to or immediately following auditory fear memory reactivation in rats. Memory strength was assessed by measuring freezing behavior 24h later. Follow up experiments were designed to investigate an effect of pre-reactivation ketamine on short-term memory (STM), closely related memories, and basolateral amygdala (BLA) specific destabilization mechanisms. RESULTS Rats given pre-reactivation, but not post-reactivation, ketamine showed larger freezing responses 24h later compared to vehicle. This enhancement was not observed 3h after the memory reactivation, nor was it seen in a closely related contextual memory. Prior inhibition of a known destabilization mechanism in the BLA blocked the effect of pre-reactivation ketamine. CONCLUSIONS Pre- but not post-reactivation ketamine enhances fear memory. These data together with recent data in human subjects supports a model of delusion fixity that proposes that aberrant prediction errors result in enhanced destabilization and strengthening of delusional belief.
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Affiliation(s)
- Michael J Honsberger
- Yale University Department of Psychiatry, Division of Molecular Psychiatry, Connecticut Mental Health Center, Abraham Ribicoff Research Facility, 34 Park Street, New Haven 06511, United States
| | - Jane R Taylor
- Yale University Department of Psychiatry, Division of Molecular Psychiatry, Connecticut Mental Health Center, Abraham Ribicoff Research Facility, 34 Park Street, New Haven 06511, United States
| | - Philip R Corlett
- Yale University Department of Psychiatry, Division of Molecular Psychiatry, Connecticut Mental Health Center, Abraham Ribicoff Research Facility, 34 Park Street, New Haven 06511, United States
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34
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Griffiths O, Langdon R, Le Pelley ME, Coltheart M. Delusions and prediction error: re-examining the behavioural evidence for disrupted error signalling in delusion formation. Cogn Neuropsychiatry 2015; 19:439-67. [PMID: 24702287 DOI: 10.1080/13546805.2014.897601] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION There is now significant evidence that prediction error signalling is mediated by dopamine in the midbrain, and that dopamine dysfunction is implicated in people experiencing psychotic symptoms, including delusions. There has also been significant theorizing and experimentation concerning the remaining link in this triad, namely that deviant prediction error signalling produces or maintains psychotic symptoms. METHODS The research supporting the link between prediction error signalling and delusional symptoms was reviewed. Numerous studies indirectly support this link, but only one set of studies claim to directly test this hypothesis by combining three crucial elements: a patient sample, a manipulation of prediction error and neuroimaging. This particular set of studies were examined in detail. RESULTS Important methodological limitations in these studies were observed, and a reinterpretation of their data was offered. CONCLUSIONS Methodological inconsistencies significantly weaken the claims made by these studies, but their data are consistent with current theorizing and they are instructive for future lines of inquiry in this field.
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Affiliation(s)
- Oren Griffiths
- a School of Psychology , University of NSW , Anzac Pde, Kensigton, Sydney , NSW 2052 , Australia
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35
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Abstract
Griffiths and colleagues provided a clear and thoughtful review of the prediction error model of delusion formation [Cognitive Neuropsychiatry, 2014 April 4 (Epub ahead of print)]. As well as reviewing the central ideas and concluding that the existing evidence base is broadly supportive of the model, they provide a detailed critique of some of the experiments that we have performed to study it. Though they conclude that the shortcomings that they identify in these experiments do not fundamentally challenge the prediction error model, we nevertheless respond to these criticisms. We begin by providing a more detailed outline of the model itself as there are certain important aspects of it that were not covered in their review. We then respond to their specific criticisms of the empirical evidence. We defend the neuroimaging contrasts that we used to explore this model of psychosis arguing that, while any single contrast entails some ambiguity, our assumptions have been justified by our extensive background work before and since.
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Affiliation(s)
- Philip Robert Corlett
- Department of Psychiatry, Ribicoff Research Facility, Yale University, 34 Park Street, New Haven, CT, USA,Corresponding author.
| | - Paul Charles Fletcher
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, CambridgeCB2 0SP, UK,Department of Psychiatry, Cambridgeshire and Peterborough Mental Health Partnership NHS Trust, CambridgeCB1 5EE, UK
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36
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Abstract
Many psychiatric disorders are characterized by intrusive, distracting, and disturbing memories that either perpetuate the illness or hinder successful treatment. For example, posttraumatic stress disorder (PTSD) involves such strong reemergence of memories associated with a traumatic event that the individual feels like the event is happening again. Furthermore, drug addiction is characterized by compulsive use and repeated relapse that is often driven by internal memories of drug use and/or by exposure to external stimuli that were associated with drug use. Therefore, identifying pharmacological methods to weaken the strength of maladaptive memories is a major goal of research efforts aimed at finding new treatments for these disorders. The primary mechanism by which memories could be pharmacologically disrupted or altered is through manipulation of memory reconsolidation. Reconsolidation occurs when an established memory is remembered or reactivated, reentering a labile state before again being consolidated into long-term memory storage. Memories are subject to disruption during this labile state. In this chapter we will discuss the preclinical and clinical studies identifying potential pharmacological methods for disrupting the integrity of maladaptive memory to treat mental illness.
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Affiliation(s)
- Jane R Taylor
- Department of Psychiatry, Yale University, New Haven, CT, USA
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37
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Abstract
Schizophrenia is a mental disorder associated with a variety of symptoms, including hallucinations, delusions, social withdrawal, and cognitive dysfunction. Impairments on decision-making tasks are routinely reported: evidence points to a particular deficit in learning from and revising behavior following feedback. In addition, patients tend to make hasty decisions when probabilistic judgments are required. This is known as "jumping to conclusions" (JTC) and has typically been demonstrated by presenting participants with colored beads drawn from one of two "urns" until they claim to be sure which urn the beads are being drawn from (the proportions of colors vary in each urn). Patients tend to make early decisions on this task, and there is evidence to suggest that a hasty decision-making style might be linked to delusion formation and thus be of clinical relevance. Various accounts have been proposed regarding what underlies this behavior. In this review, we briefly introduce the disorder and the decision-making deficits associated with it. We then explore the evidence for each account of JTC in the context of a wider decision-making deficit and then go on to summarize work exploring JTC in healthy controls using pharmacological manipulations and functional imaging. Finally, we assess whether JTC might have a role in therapy.
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Affiliation(s)
- Simon L Evans
- School of Psychology, University of Sussex, Brighton, East Sussex, UK
| | - Bruno B Averbeck
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Nicholas Furl
- Department of Psychology, Royal Holloway, University of London, Egham, Surrey, UK
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38
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Powers AR, Gancsos MG, Finn ES, Morgan PT, Corlett PR. Ketamine-Induced Hallucinations. Psychopathology 2015; 48:376-85. [PMID: 26361209 PMCID: PMC4684980 DOI: 10.1159/000438675] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/11/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Ketamine, the NMDA glutamate receptor antagonist drug, is increasingly employed as an experimental model of psychosis in healthy volunteers. At subanesthetic doses, it safely and reversibly causes delusion-like ideas, amotivation and perceptual disruptions reminiscent of the aberrant salience experiences that characterize first-episode psychosis. However, auditory verbal hallucinations, a hallmark symptom of schizophrenia, have not been reported consistently in healthy volunteers even at high doses of ketamine. SAMPLING AND METHODS Here we present data from a set of healthy participants who received moderately dosed, placebo-controlled ketamine infusions in the reduced stimulation environment of the magnetic resonance imaging (MRI) scanner. We highlight the phenomenological experiences of 3 participants who experienced particularly vivid hallucinations. RESULTS Participants in this series reported auditory verbal and musical hallucinations at a ketamine dose that does not induce auditory hallucination outside of the scanner. CONCLUSIONS We interpret the observation of ketamine-induced auditory verbal hallucinations in the context of the reduced perceptual environment of the MRI scanner and offer an explanation grounded in predictive coding models of perception and psychosis - the brain fills in expected perceptual inputs, and it does so more in situations of altered perceptual input. The altered perceptual input of the MRI scanner creates a mismatch between top-down perceptual expectations and the heightened bottom-up signals induced by ketamine. Such circumstances induce aberrant percepts, including musical and auditory verbal hallucinations. We suggest that these circumstances might represent a useful experimental model of auditory verbal hallucinations and highlight the impact of ambient sensory stimuli on psychopathology.
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Affiliation(s)
- Albert R Powers
- Department of Psychiatry, Yale School of Medicine, Yale University, New Haven, Conn., USA
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Das RK, Hindocha C, Freeman TP, Lazzarino AI, Curran HV, Kamboj SK. Assessing the translational feasibility of pharmacological drug memory reconsolidation blockade with memantine in quitting smokers. Psychopharmacology (Berl) 2015; 232:3363-74. [PMID: 26093656 PMCID: PMC4537501 DOI: 10.1007/s00213-015-3990-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 06/01/2015] [Indexed: 11/28/2022]
Abstract
RATIONALE Preclinical reconsolidation research offers the first realistic opportunity to pharmacologically weaken the maladaptive memory structures that support relapse in drug addicts. N-methyl D-aspartate receptor (NMDAR) antagonism is a highly effective means of blocking drug memory reconsolidation. However, no research using this approach exists in human addicts. OBJECTIVES The objective of this study was to assess the potential and clinical outcomes of blocking the reconsolidation of cue-smoking memories with memantine in quitting smokers. METHODS Fifty-nine dependent and motivated to quit smokers were randomised to one of three groups receiving the following: (1) memantine with or (2) without reactivation of associative cue-smoking memories or (3) reactivation with placebo on their target quit day in a double-blind manner. Participants aimed to abstain from smoking for as long as possible. Levels of smoking and FTND score were assessed prior to intervention and up to a year later. Primary outcome was latency to relapse. Subjective craving measures and attentional bias to smoking cues were assessed in-lab. RESULTS All study groups successfully reduced their smoking up to 3 months. Memantine in combination with smoking memory reactivation did not affect any measure of smoking outcome, reactivity or attention capture to smoking cues. CONCLUSIONS Brief exposure to smoking cues with memantine did not appear to weaken these memory traces. These findings could be due to insufficient reconsolidation blockade by memantine or failure of exposure to smoking stimuli to destabilise smoking memories. Research assessing the treatment potential of reconsolidation blockade in human addicts should focus on identification of tolerable drugs that reliably block reward memory reconsolidation and retrieval procedures that reliably destabilise strongly trained memories.
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Affiliation(s)
- Ravi K Das
- Clinical Psychopharmacology Unit, University College London, 1-19 Torrington Place, London, WC1E 6BT, UK,
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Walter M, Li S, Demenescu LR. Multistage drug effects of ketamine in the treatment of major depression. Eur Arch Psychiatry Clin Neurosci 2014; 264 Suppl 1:S55-65. [PMID: 25217177 DOI: 10.1007/s00406-014-0535-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 09/02/2014] [Indexed: 01/17/2023]
Abstract
A substantial number of patients diagnosed with major depression disorder show poor or no response to standard antidepressive drugs. Recent studies showed that ketamine promotes a rapid and sustained antidepressive effect in treatment-resistant depression. Importantly, after a single dose, such antidepressant action appears very fast, reaching maximum efficacy after 1-2 days before it slowly decays after 3-7 days. This temporal pattern is especially interesting since most effects are investigated following single, subanesthetic doses. This means that effects are observed at time points when the blood levels have long fallen below any active threshold. Mechanisms of action thus may be sought either in secondary or compensatory processes, which develop after acute systemic derangement or in molecular downstream mechanisms of action, which after initiation do not require the presence of active drug levels. We here review acute and delayed effects of subanesthetic ketamine infusion and discuss potential origins of antidepressant drug action. We will provide evidences that both acute effects on abnormal network configuration and delayed effects at the level of homeostatic synaptic plasticity may be necessary for antidepressant action. We further argue that such effects should be followed by a temporally well-defined exploitation of these transient changes by therapeutic processes, aiming at sustained changes of network configuration via psychotherapeutic or other methods.
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Affiliation(s)
- Martin Walter
- Clinical Affective Neuroimaging Laboratory (CANLAB), Otto-von-Guericke-University, ZENIT, Leipziger Str. 44, 39120, Magdeburg, Germany,
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Forcato C, Fernandez RS, Pedreira ME. Strengthening a consolidated memory: the key role of the reconsolidation process. ACTA ACUST UNITED AC 2014; 108:323-33. [PMID: 25218188 DOI: 10.1016/j.jphysparis.2014.09.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 06/30/2014] [Accepted: 09/02/2014] [Indexed: 02/07/2023]
Abstract
The reconsolidation hypothesis posits that the presentation of a specific cue, previously associated with a life event, makes the stored memory pass from a stable to a reactivated state. In this state, memory is again labile and susceptible to different agents, which may either damage or improve the original memory. Such susceptibility decreases over time and leads to a re-stabilization phase known as reconsolidation process. This process has been assigned two biological roles: memory updating, which suggests that destabilization of the original memory allows the integration of new information into the background of the original memory; and memory strengthening, which postulates that the labilization-reconsolidation process strengthens the original memory. The aim of this review is to analyze the strengthening as an improvement obtained only by triggering such process without any other treatment. In our lab, we have demonstrated that when triggering the labilization-reconsolidation process at least once the original memory becomes strengthened and increases its persistence. We have also shown that repeated labilization-reconsolidation processes strengthened the original memory by enlarging its precision, and said reinforced memories were more resistant to interference. Finally, we have shown that the strengthening function is not operative in older memories. We present and discuss both our findings and those of others, trying to reveal the central role of reconsolidation in the modification of stored information.
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Affiliation(s)
- Cecilia Forcato
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE - CONICET, Ciudad Universitaria, Pab. II (1428) Buenos Aires, Argentina; Department of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Rodrigo S Fernandez
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE - CONICET, Ciudad Universitaria, Pab. II (1428) Buenos Aires, Argentina
| | - María E Pedreira
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE - CONICET, Ciudad Universitaria, Pab. II (1428) Buenos Aires, Argentina.
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Agren T. Human reconsolidation: a reactivation and update. Brain Res Bull 2014; 105:70-82. [PMID: 24397965 DOI: 10.1016/j.brainresbull.2013.12.010] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 12/21/2013] [Accepted: 12/24/2013] [Indexed: 02/02/2023]
Abstract
The reconsolidation hypothesis states that memories, when reactivated, enter a transient, labile state followed by a re-stabilization termed reconsolidation. By affecting the reconsolidation process, memory persistence can be influenced, leading to memory enhancement or decrement. This is a time-dependent process and the result of modulating reconsolidation is present only after the reconsolidation process is completed. Historically, reconsolidation research has been performed on non-human animals, since the methods originally used for reconsolidation disruption are not safe. However, there now exist several techniques safe for humans, and consequently, in recent years, papers on human reconsolidation have emerged. Here, the existing literature on human reconsolidation is reviewed and discussed, including studies on fear memories, appetitive memories, procedural memories, and declarative memories. Methods of memory reactivation are compared between studies, and the consistency and lack of consistency in results over reactivation methods and memory types are discussed. These results provide future challenges, both experimental and clinical, in defining the boundary conditions and mechanisms governing the reconsolidation phenomenon. This article is part of a Special Issue entitled 'Memory Enhancement'.
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Affiliation(s)
- Thomas Agren
- Department of Psychology, Uppsala University, Uppsala, Sweden.
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