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Poplin T, Ironside M, Kuplicki R, Aupperle RL, Guinjoan SM, Khalsa SS, Stewart JL, Victor TA, Paulus MP, Kirlic N. The unique face of anxious depression: Increased sustained threat circuitry response during fear acquisition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.562565. [PMID: 37905149 PMCID: PMC10614928 DOI: 10.1101/2023.10.17.562565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Background Sensitivity to threat with dysregulation of fear learning is thought to contribute to the development of psychiatric disorders, including anxiety disorders (AD) and major depressive disorder (MDD). However, fewer studies have examined fear learning in MDD than in AD. Nearly half of individuals with MDD have an AD and the comorbid diagnosis has worse outcomes. The current study used propensity matching to examine the hypothesis that AD+MDD shows greater neural correlates of fear learning than MDD, suggesting that the co-occurrence of AD+MDD is exemplified by exaggerated defense related processes. Methods 195 individuals with MDD (N = 65) or AD+MDD (N=130) were recruited from the community and completed multi-level assessments, including a Pavlovian fear learning task during functional imaging. Results MDD and AD+MDD showed significantly different patterns of activation for [CSplus-CSminus] in the medial amygdala (ηp2=0.009), anterior insula (ηp2=0.01), dorsolateral prefrontal cortex (ηp2=0.002), dorsal anterior cingulate cortex (ηp2=0.01), mid-cingulate cortex (ηp2=0.01) and posterior cingulate cortex (ηp2=0.02). These differences were driven by greater activation to the CS+ in late conditioning phases in ADD+MDD relative to MDD. Conclusions AD+MDD showed a pattern of increased sustained activation in regions identified with fear learning. Effects were consistently driven by the threat condition, further suggesting fear signaling as the emergent target process. Differences emerged in regions associated with salience processing, attentional orienting/conflict, and self-relevant processing.These findings help to elucidate the fear signaling mechanisms involved in the pathophysiology of comorbid anxiety and depression, thereby highlighting promising treatment targets for this prevalent treatment group.
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Affiliation(s)
- Tate Poplin
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
| | - Maria Ironside
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
- University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Rayus Kuplicki
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
| | - Robin L. Aupperle
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
- University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Salvador M. Guinjoan
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
- University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Sahib S. Khalsa
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
- University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Jennifer L. Stewart
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
- University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Teresa A. Victor
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
| | - Martin P. Paulus
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
- University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Namik Kirlic
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
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Lubin RE, Fitzgerald HE, Rosenfield D, Carpenter JK, Papini S, Dutcher CD, Dowd SM, Hofmann SG, Pollack MH, Smits JAJ, Otto MW. Using pre-treatment de novo threat conditioning outcomes to predict treatment response to DCS augmentation of exposure-based CBT. J Psychiatr Res 2023; 164:357-363. [PMID: 37399757 PMCID: PMC10557473 DOI: 10.1016/j.jpsychires.2023.06.008] [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: 03/16/2023] [Revised: 06/07/2023] [Accepted: 06/15/2023] [Indexed: 07/05/2023]
Abstract
BACKGROUND Over a decade and a half of research has resulted in inconsistent evidence for the efficacy of d-cycloserine (DCS), a partial glutamatergic N-methyl-D-aspartate agonist, for augmenting exposure-based cognitive behavioral therapy (CBT) for anxiety- and fear-based disorders. These variable findings have motivated the search for moderators of DCS augmentation efficacy. METHODS In this secondary analysis of a previous randomized clinical trial, we evaluated the value of de novo threat conditioning outcomes-degree of threat acquisition, extinction, and extinction retention-for predicting treatment response to exposure-based CBT for social anxiety disorder, applied with and without DCS augmentation in a sample of 59 outpatients. RESULTS We found that average differential skin conductance response (SCR) during extinction and extinction retention significantly moderated the prediction of clinical response to DCS: participants with poorer extinction and extinction retention showed relatively improved treatment response with DCS. No such effects were found for expectancy ratings, consistent with accounts of DCS selectively aiding lower-order but not higher-order extinction learning. CONCLUSIONS These findings provide support for extinction and extinction retention outcomes from threat conditioning as potential pre-treatment biomarkers for DCS augmentation benefits. Independent of DCS augmentation, the current study did not support threat conditioning outcomes as useful for predicting response to exposure-based CBT.
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Affiliation(s)
- Rebecca E Lubin
- Department of Psychological and Brain Sciences, Boston University, 900 Commonwealth Ave, 2nd Fl, Boston, MA, 02215, USA.
| | - Hayley E Fitzgerald
- Department of Psychological and Brain Sciences, Boston University, 900 Commonwealth Ave, 2nd Fl, Boston, MA, 02215, USA
| | - David Rosenfield
- Department of Psychology, Southern Methodist University, 6116 North Central Expressway, Dallas, TX, 75206, USA
| | - Joseph K Carpenter
- National Center for Posttraumatic Stress Disorder, Women's Health Sciences Division, 150 S Huntington Ave, Boston, MA, 02130, USA; VA Boston Healthcare System, 150 S Huntington Ave, Boston, MA, 02130, USA; Department of Psychiatry, Boston University Chobanian & Avedisian School of Medicine, 72 E Concord St, Boston, MA, 02118, USA
| | - Santiago Papini
- Division of Research, Kaiser Permanente Northern California, 2000 Broadway, Oakland, CA, 94612, USA
| | - Christina D Dutcher
- Institute of Mental Health Research and Department of Psychology, The University of Texas at Austin, 108 E Dean Keeton St, Austin, TX, 78712, USA
| | - Sheila M Dowd
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, 1645 West Jackson Blvd Suite 400, Chicago, IL, 60612, USA
| | - Stefan G Hofmann
- Department of Clinical Psychology, Philipps University Marburg, Schulstrasse 12, 35037, Marburg/Lahn, Germany
| | - Mark H Pollack
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, 1645 West Jackson Blvd Suite 400, Chicago, IL, 60612, USA; Sage Therapeutics, 215 First St, Cambridge, MA, 02142, USA
| | - Jasper A J Smits
- Institute of Mental Health Research and Department of Psychology, The University of Texas at Austin, 108 E Dean Keeton St, Austin, TX, 78712, USA
| | - Michael W Otto
- Department of Psychological and Brain Sciences, Boston University, 900 Commonwealth Ave, 2nd Fl, Boston, MA, 02215, USA
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Cain CK. Beyond Fear, Extinction, and Freezing: Strategies for Improving the Translational Value of Animal Conditioning Research. Curr Top Behav Neurosci 2023; 64:19-57. [PMID: 37532965 PMCID: PMC10840073 DOI: 10.1007/7854_2023_434] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Translational neuroscience for anxiety has had limited success despite great progress in understanding the neurobiology of Pavlovian fear conditioning and extinction. This chapter explores the idea that conditioning paradigms have had a modest impact on translation because studies in animals and humans are misaligned in important ways. For instance, animal conditioning studies typically use imminent threats to assess short-duration fear states with single behavioral measures (e.g., freezing), whereas human studies typically assess weaker or more prolonged anxiety states with physiological (e.g., skin conductance) and self-report measures. A path forward may be more animal research on conditioned anxiety phenomena measuring dynamic behavioral and physiological responses in more complex environments. Exploring transitions between defensive brain states during extinction, looming threats, and post-threat recovery may be particularly informative. If care is taken to align paradigms, threat levels, and measures, this strategy may reveal stable patterns of non-conscious defense in animals and humans that correlate better with conscious anxiety. This shift in focus is also warranted because anxiety is a bigger problem than fear, even in disorders defined by dysfunctional fear or panic reactions.
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Affiliation(s)
- Christopher K Cain
- Department of Child and Adolescent Psychiatry, NYU Langone Health, New York, NY, USA.
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
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Borghese F, Henckaerts P, Guy F, Perez Mayo C, Delplanque S, Schwartz S, Perogamvros L. Targeted Memory Reactivation During REM Sleep in Patients With Social Anxiety Disorder. Front Psychiatry 2022; 13:904704. [PMID: 35845468 PMCID: PMC9281560 DOI: 10.3389/fpsyt.2022.904704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Social anxiety disorder (SAD) is characterized by a significant amount of fear when confronted to social situations. Exposure therapy, which is based on fear extinction, does not often lead to full remission. Here, based on evidence showing that rapid eye movement (REM) sleep promotes the consolidation of extinction memory, we used targeted memory reactivation (TMR) during REM sleep to enhance extinction learning in SAD. METHODS Forty-eight subjects with SAD were randomly assigned to two groups: control or TMR group. All patients had two successive exposure therapy sessions in a virtual reality (VR) environment, where they were asked to give a public talk in front of a virtual jury. At the end of each session, and only in the TMR group (N = 24), a sound was paired to the positive feedback phase of therapy (i.e., approval of their performance), which represented the memory to be strengthened during REM sleep. All participants slept at home with a wearable headband device which automatically identified sleep stages and administered the sound during REM sleep. Participants' anxiety level was assessed using measures of parasympathetic (root mean square of successive differences between normal heartbeats, RMSSD) and sympathetic (non-specific skin conductance responses, ns-SCRs) activity, and subjective measures (Subjective Units of Distress Scale, SUDS), during the preparation phase of their talks before (T1) and after (T2) one full-night's sleep and after 1 week at home (T3). Participants also filled in a dream diary. RESULTS We observed an effect of time on subjective measures of anxiety (SUDS). We did not find any difference in the anxiety levels of the two groups after 1 week of TMR at home. Importantly, the longer the total duration of REM sleep and the more stimulations the TMR group had at home, the less anxious (increased RMSSD) these participants were. Finally, fear in dreams correlated positively with ns-SCRs and SUDS at T3 in the TMR group. CONCLUSION TMR during REM sleep did not significantly modulate the beneficial effect of therapy on subjective anxiety. Yet, our results support that REM sleep can contribute to extinction processes and substantiate strong links between emotions in dreams and waking stress levels in these patients.
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Affiliation(s)
- Francesca Borghese
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Pauline Henckaerts
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Fanny Guy
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Coral Perez Mayo
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Sylvain Delplanque
- Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland
| | - Sophie Schwartz
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.,Human Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland
| | - Lampros Perogamvros
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.,Human Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland.,Center for Sleep Medicine, Geneva University Hospitals, Geneva, Switzerland.,Department of Psychiatry, Geneva University Hospitals, Geneva, Switzerland
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5
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Roy N, Parhar I. Habenula orphan G-protein coupled receptors in the pathophysiology of fear and anxiety. Neurosci Biobehav Rev 2021; 132:870-883. [PMID: 34801259 DOI: 10.1016/j.neubiorev.2021.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/02/2021] [Accepted: 11/08/2021] [Indexed: 10/19/2022]
Abstract
The phasic emotion, fear, and the tonic emotion, anxiety, have been conventionally inspected in clinical frameworks to epitomize memory acquisition, storage, and retrieval. However, inappropriate expression of learned fear in a safe environment and its resistance to suppression is a cardinal feature of various fear-related disorders. A significant body of literature suggests the involvement of extra-amygdala circuitry in fear disorders. Consistent with this view, the present review underlies incentives for the association between the habenula and fear memory. G protein-coupled receptors (GPCRs) are important to understand the molecular mechanisms central to fear learning due to their neuromodulatory role. The efficacy of a pharmacological strategy aimed at exploiting habenular-GPCR desensitization machinery can serve as a therapeutic target combating the pathophysiology of fear disorders. Originating from this milieu, the conserved nature of orphan GPCRs in the brain, with some having the highest expression in the habenula can lead to recent endeavors in understanding its functionality in fear circuitry.
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Affiliation(s)
- Nisa Roy
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
| | - Ishwar Parhar
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
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Both S, Van Veen RJB, Brom M, Weijenborg PTM. A randomized, placebo-controlled laboratory study of the effects of D-cycloserine on sexual memory consolidation in women. Psychopharmacology (Berl) 2020; 237:1291-1303. [PMID: 31984445 PMCID: PMC7196949 DOI: 10.1007/s00213-020-05457-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 01/10/2020] [Indexed: 11/29/2022]
Abstract
RATIONALE AND OBJECTIVE The aim of this study was to investigate the possible facilitating effect of the partial NMDA receptor agonist D-cycloserine (DCS) on memory consolidation of conditioned sexual responses and to examine the capability of DCS to reduce context-specificity of learning. METHODS In a randomized placebo-controlled double-blind trial, 50 healthy females were exposed to a differential conditioning procedure. Two pictures of a male abdomen were used as conditional stimuli (CSs), of which one (the CS+) was followed by the unconditional stimulus (US), a genital vibrotactile stimulus. After the conditioning session on day 1, participants received either 125 mg of DCS or a placebo. The effects of DCS on affect, sexual arousal and US expectancy in response to the CS+ and CS- were examined 24 h after the conditioning procedure. RESULTS A main effect of DCS was found on affect at the first test trials (p = 0.04, ηp2 = 0.09), and a similar non-significant but trend level effect was found for sexual arousal (p = 0.06, ηp2 = 0.07), which appeared to persist over a longer time (p = 0.07, ηp2 = 0.08). Unexpectedly, ratings of positive affect and sexual arousal in response to both the CS+ and the CS- were higher in the DCS condition compared to the control condition, possibly indicating that DCS administration reduced stimulus specificity. Since the results did not show clear evidence for context learning, we were not able to test effects on context-specificity of learning. CONCLUSION Although largely inconclusive, the results provide tentative support for a facilitating effect of DCS on affect and sexual arousal in response to stimuli that were presented in a sexual conditioning procedure, however, no conclusions can be drawn about effects of DCS on sexual reward learning, since the design and results do not lend themselves to unambiguous interpretation.
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Affiliation(s)
- S. Both
- Department of Psychosomatic Gynecology and Sexology, Leiden University Medical Center, Poortgebouw-Zuid, 4e etage, Rijnsburgerweg 10, 2333 AA Leiden, The Netherlands
| | - R. J. B. Van Veen
- Department of Psychosomatic Gynecology and Sexology, Leiden University Medical Center, Poortgebouw-Zuid, 4e etage, Rijnsburgerweg 10, 2333 AA Leiden, The Netherlands
| | - M. Brom
- Department of Psychosomatic Gynecology and Sexology, Leiden University Medical Center, Poortgebouw-Zuid, 4e etage, Rijnsburgerweg 10, 2333 AA Leiden, The Netherlands
| | - P. T. M. Weijenborg
- Department of Psychosomatic Gynecology and Sexology, Leiden University Medical Center, Poortgebouw-Zuid, 4e etage, Rijnsburgerweg 10, 2333 AA Leiden, The Netherlands
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7
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Hofmann SG, Papini S, Carpenter JK, Otto MW, Rosenfield D, Dutcher CD, Dowd S, Lewis M, Witcraft S, Pollack MH, Smits JAJ. Effect of d-cycloserine on fear extinction training in adults with social anxiety disorder. PLoS One 2019; 14:e0223729. [PMID: 31622374 PMCID: PMC6797442 DOI: 10.1371/journal.pone.0223729] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/26/2019] [Indexed: 12/17/2022] Open
Abstract
Preclinical and clinical data have shown that D-cycloserine (DCS), a partial agonist at the N-methyl-d-aspartate receptor complex, augments the retention of fear extinction in animals and the therapeutic learning from exposure therapy in humans. However, studies with non-clinical human samples in de novo fear conditioning paradigms have demonstrated minimal to no benefit of DCS. The aim of this study was to evaluate the effects of DCS on the retention of extinction learning following de novo fear conditioning in a clinical sample. Eighty-one patients with social anxiety disorder were recruited and underwent a previously validated de novo fear conditioning and extinction paradigm over the course of three days. Of those, only 43 (53%) provided analyzable data. During conditioning on Day 1, participants viewed images of differently colored lamps, two of which were followed by with electric shock (CS+) and a third which was not (CS-). On Day 2, participants were randomly assigned to receive either 50 mg DCS or placebo, administered in a double-blind manner 1 hour prior to extinction training with a single CS+ in a distinct context. Day 3 consisted of tests of extinction recall and renewal. The primary outcome was skin conductance response to conditioned stimuli, and shock expectancy ratings were examined as a secondary outcome. Results showed greater skin conductance and expectancy ratings in response to the CS+ compared to CS- at the end of conditioning. As expected, this difference was no longer present at the end of extinction training, but returned at early recall and renewal phases on Day 3, showing evidence of return of fear. In contrast to hypotheses, DCS had no moderating influence on skin conductance response or expectancy of shock during recall or renewal phases. We did not find evidence of an effect of DCS on the retention of extinction learning in humans in this fear conditioning and extinction paradigm.
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Affiliation(s)
- Stefan G. Hofmann
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
- * E-mail:
| | - Santiago Papini
- Department of Psychology, University of Texas at Austin, Austin, Texas, United States of America
| | - Joseph K. Carpenter
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Michael W. Otto
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
| | - David Rosenfield
- Department of Psychology, Southern Methodist University, Dallas, Texas, United States of America
| | - Christina D. Dutcher
- Department of Psychology, University of Texas at Austin, Austin, Texas, United States of America
| | - Sheila Dowd
- Department of Psychiatry, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Mara Lewis
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Sara Witcraft
- Department of Psychology, University of Mississippi, Oxford, Mississippi, United States of America
| | - Mark H. Pollack
- Department of Psychiatry, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Jasper A. J. Smits
- Department of Psychology, University of Texas at Austin, Austin, Texas, United States of America
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N-Methyl D-aspartate receptor subunit signaling in fear extinction. Psychopharmacology (Berl) 2019; 236:239-250. [PMID: 30238131 PMCID: PMC6374191 DOI: 10.1007/s00213-018-5022-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 09/03/2018] [Indexed: 01/13/2023]
Abstract
N-Methyl D-aspartate receptors (NMDAR) are central mediators of glutamate actions underlying learning and memory processes including those required for extinction of fear and fear-related behaviors. Consistent with this view, in animal models, antagonists of NMDAR typically impair fear extinction, whereas partial agonists have facilitating effects. Promoting NMDAR function has thus been recognized as a promising strategy towards reduction of fear symptoms in patients suffering from anxiety disorders and post-traumatic disorder (PTSD). Nevertheless, application of these drugs in clinical trials has proved of limited utility. Here we summarize recent advances in our knowledge of NMDAR pharmacology relevant for fear extinction, focusing on molecular, cellular, and circuit aspects of NMDAR function as they relate to fear extinction at the level of behavior and cognition. We also discuss how these advances from animal models might help to understand and overcome the limitations of existing approaches in human anxiety disorders and how novel, more specific, and personalized approaches might help advance future therapeutic strategies.
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Effects of post-exposure naps on exposure therapy for social anxiety. Psychiatry Res 2018; 270:523-530. [PMID: 30340182 PMCID: PMC6292728 DOI: 10.1016/j.psychres.2018.10.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 10/07/2018] [Accepted: 10/07/2018] [Indexed: 01/13/2023]
Abstract
Exposure therapy for social anxiety disorder (SAD) utilizes fear extinction, a memory process enhanced by sleep. We investigated whether naps following exposure sessions might improve symptoms and biomarkers in response to social stress in adults undergoing 5-week exposure-based group SAD therapy. Thirty-two participants aged 18-39 (18 females) with SAD were randomized. Before and after treatment, participants completed the Liebowitz Social Anxiety Scale (LSAS) and underwent a Trier Social Stress Test with psychophysiological monitoring (mpTSST) that included skin conductance (SCL), electromyographic (EMG) and electrocardiographic recording, and an auditory startle procedure while anticipating the social stressor. At sessions 3 and 4, exposure was followed by either a 120-min polysomnographically monitored sleep opportunity (Nap, N = 17) or wakefulness (Wake, N = 15). Primary hypotheses about SAD symptom change (LSAS) and EMG blink-startle response failed to differ with naps, despite significant symptom improvement (LSAS) with therapy. Some secondary biomarkers, however, provided preliminary support for enhanced extinction learning with naps, with trend-level Time (pre-, post-treatment) × Arm interactions and significant reduction from pre- to post treatment in the Nap arm alone for mpTSST SCL and salivary cortisol rise. Because of the small sample size and limited sleep duration, additional well-powered studies with more robust sleep interventions are indicated.
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Alizadeh Asfestani M, Braganza E, Schwidetzky J, Santiago J, Soekadar S, Born J, Feld GB. Overnight memory consolidation facilitates rather than interferes with new learning of similar materials-a study probing NMDA receptors. Neuropsychopharmacology 2018; 43:2292-2298. [PMID: 30046156 PMCID: PMC6135744 DOI: 10.1038/s41386-018-0139-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 06/18/2018] [Accepted: 06/22/2018] [Indexed: 12/21/2022]
Abstract
Although sleep-dependent consolidation and its neurochemical underpinnings have been strongly researched, less is known about how consolidation during sleep affects subsequent learning. Since sleep enhances memory, it can be expected to pro-actively interfere with learning after sleep, in particular of similar materials. This pro-active interference should be enhanced by substances that benefit consolidation during sleep, such as D-cycloserine. We tested this hypothesis in two groups (Sleep, Wake) of young healthy participants receiving on one occasion D-cycloserine (175 mg) and on another occasion placebo, according to a double-blind balanced crossover design. Treatment was administered after participants had learned a set of word pairs (A-B list) and before nocturnal retention periods of sleep vs. wakefulness. After D-cycloserine blood plasma levels had dropped to negligible amounts, i.e., the next day in the evening, participants learned, in three sequential runs, new sets of word pairs. One list-to enhance interference-consisted of the same cue words as the original set paired with a new target word (A-C list) and the other of completely new cue words (D-E set). Unexpectedly, during post-retention learning the A-C interference list was generally better learned than the completely new D-E list, which suggests that consolidation of previously encoded similar material enhances memory integration rather than pro-active interference. Consistent with this view, new learning of word pairs was better after sleep than wakefulness. Similarly, D-cycloserine generally enhanced learning of new word pairs, compared to placebo. This effect being independent of sleep or wakefulness, leads us to speculate that D-cycloserine, in addition to enhancing sleep-dependent consolidation, might mediate a time-dependent process of active forgetting.
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Affiliation(s)
- M. Alizadeh Asfestani
- 0000 0001 2190 1447grid.10392.39Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - E. Braganza
- 0000 0001 2190 1447grid.10392.39Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - J. Schwidetzky
- 0000 0001 2190 1447grid.10392.39Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - J. Santiago
- 0000 0001 2190 1447grid.10392.39Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany ,grid.452622.5German Center for Diabetes Research (DZD), Tübingen, Germany ,0000 0001 2190 1447grid.10392.39Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University Tübingen, Tübingen, Germany
| | - S. Soekadar
- 0000 0001 2190 1447grid.10392.39Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - J. Born
- 0000 0001 2190 1447grid.10392.39Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany ,0000 0001 2190 1447grid.10392.39Present Address: Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - G. B. Feld
- 0000 0001 2190 1447grid.10392.39Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany ,0000000121901201grid.83440.3bDivision of Psychology and Language Sciences, University College London, London, UK ,0000000121901201grid.83440.3bDepartment of Experimental Psychology, Division of Psychology and Language Science, Institute of Behavioural Neuroscience, University College London, 26 Bedford Way, London, WC1H 0AP UK
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Pyrkosch L, Mumm J, Alt I, Fehm L, Fydrich T, Plag J, Ströhle A. Learn to forget: Does post-exposure administration of d-cycloserine enhance fear extinction in agoraphobia? J Psychiatr Res 2018; 105:153-163. [PMID: 30237105 DOI: 10.1016/j.jpsychires.2018.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/07/2018] [Accepted: 08/10/2018] [Indexed: 12/23/2022]
Abstract
The use of d-cycloserine (DCS) to augment exposure based therapy for anxiety disorders has shown mixed, although overall positive effects. Aim of the present study was to examine post-exposure administration of DCS in patients with agoraphobia with or without panic disorder. 73 patients with agoraphobia (with or without panic disorder) were treated with 12 sessions of cognitive behavioral therapy (CBT) including 3 exposures. Following successful exposure patients were given double blind either placebo or 50 mg of DCS. Primary outcome criterion was change in the Panic and Agoraphobia Scale (PAS) between CBT session t1, t4 (+∼2 months), t10 (+∼3 months) und t11 (+∼4 months). During the course of CBT the patients' symptomatology decreased significantly as measured by primary and secondary outcome criteria, however, without an additional benefit for DCS treated patients. Exploratory sub-group analyses for severely ill patients and patients with high anxiety and strong habituation during exposure showed that DCS administration was associated with increased improvement during the 1-month follow-up period (t10 - t11) with medium to large effect sizes (range in effect size η2p from .06 to .25). Our study results are consistent with recent research on DCS, indicating a beneficial augmentative effect for sub-groups of anxiety patients. The lack of an overall DCS effect for the whole patient sample might be explained by a dual mechanism in fear conditioning and extinction with different cognitive processes being involved during exposure depending on the degree of anxiety experienced by the patient.
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Affiliation(s)
- L Pyrkosch
- Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Germany.
| | - J Mumm
- Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Germany.
| | - I Alt
- Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Germany.
| | - L Fehm
- Centre of Psychotherapy at the Department of Psychology, Humboldt-Universität zu Berlin, Germany.
| | - T Fydrich
- Centre of Psychotherapy at the Department of Psychology, Humboldt-Universität zu Berlin, Germany.
| | - J Plag
- Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Germany.
| | - A Ströhle
- Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Germany.
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12
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Mertens G, Boddez Y, Sevenster D, Engelhard IM, De Houwer J. A review on the effects of verbal instructions in human fear conditioning: Empirical findings, theoretical considerations, and future directions. Biol Psychol 2018; 137:49-64. [DOI: 10.1016/j.biopsycho.2018.07.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 07/05/2018] [Accepted: 07/06/2018] [Indexed: 12/14/2022]
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13
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Kredlow MA, Orr SP, Otto MW. Exploring the boundaries of post-retrieval extinction in healthy and anxious individuals. Behav Res Ther 2018; 108:45-57. [PMID: 29981938 DOI: 10.1016/j.brat.2018.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 06/14/2018] [Accepted: 06/25/2018] [Indexed: 01/07/2023]
Abstract
Over a dozen studies have examined the efficacy of post-retrieval extinction (PRE) in healthy adults in the fear conditioning laboratory, with a recent meta-analysis reporting an overall small-moderate effect on attenuating the return of fear compared to standard extinction. The current study was designed to extend PRE effects to a mixed sample of healthy and anxious individuals, explore potential moderators, and examine the benefit of PRE for a memory conditioned over multiple days. Healthy (n = 49) and anxious (n = 43) adults received either one day of acquisition followed by PRE, one day of acquisition followed by extinction, or three days of acquisition followed by PRE. Comparing participants who received one day of acquisition followed by PRE or extinction, no significant effect of PRE was observed on differential skin conductance response reinstatement or reactivity to the conditioned stimulus alone. Anxiety symptoms did not moderate outcomes. There was no difference in return of fear for anxious participants who received three days of acquisition followed by PRE versus one day of acquisition followed by PRE. These results further highlight the variability of findings in the PRE literature and need for further examination of individual difference factors that may moderate PRE effects.
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Affiliation(s)
- M Alexandra Kredlow
- Department of Psychological & Brain Sciences, Boston University, 648 Beacon Street, 5th Floor, Boston, MA 02215, United States.
| | - Scott P Orr
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, East Building 120 -2nd Avenue, Charlestown, MA 02129, United States.
| | - Michael W Otto
- Department of Psychological & Brain Sciences, Boston University, 648 Beacon Street, 5th Floor, Boston, MA 02215, United States.
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14
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Deltomme B, Mertens G, Tibboel H, Braem S. Instructed fear stimuli bias visual attention. Acta Psychol (Amst) 2018; 184:31-38. [PMID: 28889903 DOI: 10.1016/j.actpsy.2017.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/21/2017] [Accepted: 08/24/2017] [Indexed: 10/18/2022] Open
Abstract
We investigated whether stimuli merely instructed to be fear-relevant can bias visual attention, even when the fear relation was never experienced before. Participants performed a dot-probe task with pictures of naturally fear-relevant (snake or spider) or -irrelevant (bird or butterfly) stimuli. Instructions indicated that two pictures (one naturally fear-relevant and one fear-irrelevant) could be followed by an electrical stimulation (i.e., instructed fear). In reality, no stimulation was administered. During the task, two pictures were presented on each side of the screen, after which participants had to determine as fast as possible on which side a black dot appeared. After a first phase, fear was reinstated by instructing participants that the device was not connected but now was (reinstatement phase). Participants were faster when the dot appeared on a location where an instructed fear picture was presented. This effect seemed independent of whether picture content was naturally fear-relevant, but was only found in the first half of each phase, suggesting rapid extinction due to the absence of stimulation, and rapid re-evaluation after reinstatement. A second experiment similarly showed that instructed fear biases attention, even when participants were explicitly instructed that no stimulation would be given during the dot-probe task. Together, these findings demonstrate that attention can be biased towards instructed fear stimuli, even when these fear relations were never experienced. Future studies should test whether this is specific to fear, or can be observed for all instructions that change the relevance of a given stimulus.
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Forcadell E, Torrents-Rodas D, Vervliet B, Leiva D, Tortella-Feliu M, Fullana MA. Does fear extinction in the laboratory predict outcomes of exposure therapy? A treatment analog study. Int J Psychophysiol 2017; 121:63-71. [DOI: 10.1016/j.ijpsycho.2017.09.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/24/2017] [Accepted: 09/05/2017] [Indexed: 01/20/2023]
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16
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Braem S, De Houwer J, Demanet J, Yuen KSL, Kalisch R, Brass M. Pattern Analyses Reveal Separate Experience-Based Fear Memories in the Human Right Amygdala. J Neurosci 2017; 37:8116-8130. [PMID: 28733358 PMCID: PMC6596782 DOI: 10.1523/jneurosci.0908-17.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/06/2017] [Accepted: 07/10/2017] [Indexed: 12/20/2022] Open
Abstract
Learning fear via the experience of contingencies between a conditioned stimulus (CS) and an aversive unconditioned stimulus (US) is often assumed to be fundamentally different from learning fear via instructions. An open question is whether fear-related brain areas respond differently to experienced CS-US contingencies than to merely instructed CS-US contingencies. Here, we contrasted two experimental conditions where subjects were instructed to expect the same CS-US contingencies while only one condition was characterized by prior experience with the CS-US contingency. Using multivoxel pattern analysis of fMRI data, we found CS-related neural activation patterns in the right amygdala (but not in other fear-related regions) that dissociated between whether a CS-US contingency had been instructed and experienced versus merely instructed. A second experiment further corroborated this finding by showing a category-independent neural response to instructed and experienced, but not merely instructed, CS presentations in the human right amygdala. Together, these findings are in line with previous studies showing that verbal fear instructions have a strong impact on both brain and behavior. However, even in the face of fear instructions, the human right amygdala still shows a separable neural pattern response to experience-based fear contingencies.SIGNIFICANCE STATEMENT In our study, we addressed a fundamental problem of the science of human fear learning and memory, namely whether fear learning via experience in humans relies on a neural pathway that can be separated from fear learning via verbal information. Using two new procedures and recent advances in the analysis of brain imaging data, we localized purely experience-based fear processing and memory in the right amygdala, thereby making a direct link between human and animal research.
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Affiliation(s)
- Senne Braem
- Department of Experimental Psychology and
- Department of Experimental Clinical and Health Psychology, Ghent University, 9000 Ghent, Belgium, and
| | - Jan De Houwer
- Department of Experimental Clinical and Health Psychology, Ghent University, 9000 Ghent, Belgium, and
| | | | - Kenneth S L Yuen
- Neuroimaging Center Mainz, Focus Program Translational Neuroscience and
| | - Raffael Kalisch
- Neuroimaging Center Mainz, Focus Program Translational Neuroscience and
- Deutsches Resilienz-Zentrum, Johannes Gutenberg University Medical Center, Mainz 55131, Germany
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Ebrahimi C, Koch SP, Friedel E, Crespo I, Fydrich T, Ströhle A, Heinz A, Schlagenhauf F. Combining D-cycloserine with appetitive extinction learning modulates amygdala activity during recall. Neurobiol Learn Mem 2017; 142:209-217. [PMID: 28512009 DOI: 10.1016/j.nlm.2017.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/07/2017] [Accepted: 05/12/2017] [Indexed: 01/23/2023]
Abstract
Appetitive Pavlovian conditioning plays a crucial role in the pathogenesis of drug addiction and conditioned reward cues can trigger craving and relapse even after long phases of abstinence. Promising preclinical work showed that the NMDA-receptor partial agonist D-cycloserine (DCS) facilitates Pavlovian extinction learning of fear and drug cues. Furthermore, DCS-augmented exposure therapy seems to be beneficial in various anxiety disorders, while the supposed working mechanism of DCS during human appetitive or aversive extinction learning is still not confirmed. To test the hypothesis that DCS administration before extinction training improves extinction learning, healthy adults (n=32) underwent conditioning, extinction, and extinction recall on three successive days in a randomized, double-blind, placebo-controlled fMRI design. Monetary wins and losses served as unconditioned stimuli during conditioning to probe appetitive and aversive learning. An oral dose of 50mg of DCS or placebo was administered 1h before extinction training and DCS effects during extinction recall were evaluated on a behavioral and neuronal level. We found attenuated amygdala activation in the DCS compared to the placebo group during recall of the extinguished appetitive cue, along with evidence for enhanced functional amygdala-vmPFC coupling in the DCS group. While the absence of additional physiological measures of conditioned responses during recall in this study prevent the evaluation of a behavioral DCS effect, our neuronal findings are in accordance with recent theories linking successful extinction recall in humans to modulatory top-down influences from the vmPFC that inhibit amygdala activation. Our results should encourage further translational studies concerning the usefulness of DCS to target maladaptive Pavlovian reward associations.
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Affiliation(s)
- Claudia Ebrahimi
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany.
| | - Stefan P Koch
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Eva Friedel
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Ilsoray Crespo
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Thomas Fydrich
- Department of Psychology, Humboldt University of Berlin, 10099 Berlin, Germany
| | - Andreas Ströhle
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Andreas Heinz
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany; Cluster of Excellence NeuroCure, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Florian Schlagenhauf
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany; Max Planck Institute for Human Cognitive and Brain Sciences, 04303 Leipzig, Germany
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18
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Goff DC. D-cycloserine in Schizophrenia: New Strategies for Improving Clinical Outcomes by Enhancing Plasticity. Curr Neuropharmacol 2017; 15:21-34. [PMID: 26915421 PMCID: PMC5327448 DOI: 10.2174/1570159x14666160225154812] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/13/2015] [Accepted: 01/30/2016] [Indexed: 12/25/2022] Open
Abstract
Background Dysregulation of N-methyl D-aspartate (NMDA) receptor signaling is strongly implicated in schizophrenia. Based on the ketamine model of NMDA receptor hypoactivity, therapeutic approaches designed to maintain a sustained increase in agonist activity at the glycine site of the NMDA receptor have produced promising, although inconsistent, efficacy for negative symptoms. Methods A review of the published literature on D-cycloserine (DCS) pharmacology in animal models and in clinical studies was performed. Findings relevant to DCS effects on memory and plasticity and their potential clinical application to schizophrenia were summarized. Results Studies in animals and clinical trials in patients with anxiety disorders have demonstrated that single or intermittent dosing with DCS enhances memory consolidation. Preliminary trials in patients with schizophrenia suggest that intermittent dosing with DCS may produce persistent improvement of negative symptoms and enhance learning when combined with cognitive behavioral therapy for delusions or with cognitive remediation. The pharmacology of DCS is complex, since it acts as a “super agonist” at NMDA receptors containing GluN2C subunits and, under certain conditions, it may act as an antagonist at NMDA receptors containing GluN2B subunits. Conclusions There are preliminary findings that support a role for D-cycloserine in schizophrenia as a strategy to enhance neuroplasticity and memory. However, additional studies with DCS are needed to confirm these findings. In addition, clinical trials with positive and negative allosteric modulators with greater specificity for NMDA receptor subtypes are needed to identify the optimal strategy for enhancing neuroplasticity in schizophrenia.
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Affiliation(s)
- Donald C Goff
- Nathan Kline Institute for Psychiatric Research, NYU School of Medicine, USA
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19
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Kapolowicz MR, Thompson LT. Acute high-intensity noise induces rapid Arc protein expression but fails to rapidly change GAD expression in amygdala and hippocampus of rats: Effects of treatment with D-cycloserine. Hear Res 2016; 342:69-79. [PMID: 27702572 DOI: 10.1016/j.heares.2016.09.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 08/26/2016] [Accepted: 09/30/2016] [Indexed: 10/20/2022]
Abstract
Tinnitus is a devastating auditory disorder impacting a growing number of people each year. The aims of the current experiment were to assess neuronal mechanisms involved in the initial plasticity after traumatic noise exposure that could contribute to the emergence of tinnitus and to test a potential pharmacological treatment to alter this early neural plasticity. Specifically, this study addressed rapid effects of acute noise trauma on amygdalo-hippocampal circuitry, characterizing biomarkers of both excitation and inhibition in these limbic regions, and compared them to expression of these same markers in primary auditory cortex shortly after acute noise trauma. To assess excitatory plasticity, activity-regulated cytoskeleton-associated (Arc) protein expression was evaluated in male rats 45 min after bilateral exposure to acute high-intensity noise (16 kHz, 115 dB SPL, for 1 h), sufficient to cause acute cochlear trauma, a common cause of tinnitus in humans and previously shown sufficient to induce tinnitus in rat models of this auditory neuropathology. Western blot analyses confirmed that up-regulation of amygdalo-hippocampal Arc expression occurred rapidly post-noise trauma, corroborating several lines of evidence from our own and other laboratories indicating that limbic brain structures, i.e. outside of the classical auditory pathways, exhibit plasticity early in the initiation of tinnitus. Western blot analyses revealed no noise-induced changes in amygdalo-hippocampal expression of glutamate decarboxylase (GAD), the biosynthetic enzyme required for GABAergic inhibition. No changes in either Arc or GAD protein expression were observed in primary auditory cortex in this immediate post-noise exposure period, confirming other reports that auditory cortical plasticity may not occur until later in the development of tinnitus. As a further control, our experiments compared Arc protein expression between groups exposed to the quiet background of a sound-proof chamber to those exposed not only to the traumatic noise described above, but also to an intermediate, non-traumatic noise level (70 dB SPL) for the same duration in each of these three brain regions. We found that non-traumatic noise did not up-regulate Arc protein expression in these brain regions. To see if changes in Arc expression due to acute traumatic noise exposure were stress-related, we compared circulating serum corticosterone in controls and rats exposed to traumatic noise at the time when changes in Arc were observed, and found no significant differences in this stress hormone in our experimental conditions. Finally, the ability of D-cycloserine (DCS; an NMDA-receptor NR1 partial agonist) to reduce or prevent the noise trauma-related plastic changes in the biomarker, Arc, was tested. D-cycloserine prevented traumatic noise-induced up-regulation of Arc protein expression in amygdala but not in hippocampus, suggesting that DCS alone is not fully effective in eliminating regionally-specific early plastic changes after traumatic noise exposure.
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Affiliation(s)
- M R Kapolowicz
- Behavioral & Brain Sciences, Neuroscience, The University of Texas at Dallas, 800W. Campbell Rd., BSB 14, Richardson, TX, 75080, USA
| | - L T Thompson
- Behavioral & Brain Sciences, Neuroscience, The University of Texas at Dallas, 800W. Campbell Rd., BSB 14, Richardson, TX, 75080, USA.
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20
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Otto MW, Kredlow MA, Smits JAJ, Hofmann SG, Tolin DF, de Kleine RA, van Minnen A, Evins AE, Pollack MH. Enhancement of Psychosocial Treatment With D-Cycloserine: Models, Moderators, and Future Directions. Biol Psychiatry 2016; 80:274-283. [PMID: 26520240 PMCID: PMC4808479 DOI: 10.1016/j.biopsych.2015.09.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 09/11/2015] [Accepted: 09/15/2015] [Indexed: 01/02/2023]
Abstract
Advances in the understanding of the neurobiology of fear extinction have resulted in the development of d-cycloserine (DCS), a partial glutamatergic N-methyl-D-aspartate agonist, as an augmentation strategy for exposure treatment. We review a decade of research that has focused on the efficacy of DCS for augmenting the mechanisms (e.g., fear extinction) and outcome of exposure treatment across the anxiety disorders. Following a series of small-scale studies offering strong support for this clinical application, more recent larger-scale studies have yielded mixed results, with some showing weak or no effects. We discuss possible explanations for the mixed findings, pointing to both patient and session (i.e., learning experiences) characteristics as possible moderators of efficacy, and offer directions for future research in this area. We also review recent studies that have aimed to extend the work on DCS augmentation of exposure therapy for the anxiety disorders to DCS enhancement of learning-based interventions for addiction, anorexia nervosa, schizophrenia, and depression. Here, we attend to both DCS effects on facilitating therapeutic outcomes and additional therapeutic mechanisms beyond fear extinction (e.g., appetitive extinction, hippocampal-dependent learning).
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21
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Fricchione J, Greenberg MS, Spring J, Wood N, Mueller-Pfeiffer C, Milad MR, Pitman RK, Orr SP. Delayed extinction fails to reduce skin conductance reactivity to fear-conditioned stimuli. Psychophysiology 2016; 53:1343-51. [DOI: 10.1111/psyp.12687] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 05/10/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Jon Fricchione
- Department of Psychiatry; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts USA
| | - Mark S. Greenberg
- Department of Psychiatry; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts USA
| | - Justin Spring
- Department of Psychiatry; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts USA
| | - Nellie Wood
- Department of Psychiatry; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts USA
| | - Christoph Mueller-Pfeiffer
- Department of Psychiatry and Psychotherapy; University Hospital Zurich, University of Zurich; Zurich Switzerland
| | - Mohammed R. Milad
- Department of Psychiatry; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts USA
| | - Roger K. Pitman
- Department of Psychiatry; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts USA
| | - Scott P. Orr
- Department of Psychiatry; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts USA
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23
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Anxiety-potentiated amygdala-medial frontal coupling and attentional control. Transl Psychiatry 2016; 6:e833. [PMID: 27271859 PMCID: PMC4931603 DOI: 10.1038/tp.2016.105] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 04/24/2016] [Indexed: 01/09/2023] Open
Abstract
Anxiety disorders can be treated both pharmacologically and psychologically, but many individuals either fail to respond to treatment or relapse. Improving outcomes is difficult, in part because we have incomplete understanding of the neurobiological mechanisms underlying current treatments. In a sequence of studies, we have identified 'affective bias-related' amygdala-medial cortical coupling as a candidate substrate underlying adaptive anxiety (that is, anxiety elicited by threat of shock in healthy individuals) and shown that it is also chronically engaged in maladaptive anxiety disorders. We have provided evidence that this circuit can be modulated pharmacologically, but whether this mechanism can be shifted by simple psychological instruction is unknown. In this functional magnetic resonance imaging study, we extend a previously used translational anxiety induction (threat of shock) in healthy subjects (N=43) and cognitive task to include an element of instructed attentional control. Replicating our previous findings, we show that induced anxiety engages 'affective bias-related' amygdala-dorsal medial frontal coupling during the processing of emotional faces. By contrast, instructing subjects to attend to neutral shapes (and ignore faces) disengages this circuitry and increases putative 'attentional control-related' coupling between the amygdala and a more rostral prefrontal region. These neural coupling changes are accompanied by corresponding modulation of behavioural performance. Taken together, these findings serve to further highlight the potential role of amygdala-medial frontal coupling in the pathogenesis of anxiety and highlight a mechanism by which it can be modulated via psychological instructions. This, in turn, generates hypotheses for future work exploring the mechanisms underlying psychological therapeutic interventions for anxiety.
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Abstract
Fear memory is the best-studied form of memory. It was thoroughly investigated in the past 60 years mostly using two classical conditioning procedures (contextual fear conditioning and fear conditioning to a tone) and one instrumental procedure (one-trial inhibitory avoidance). Fear memory is formed in the hippocampus (contextual conditioning and inhibitory avoidance), in the basolateral amygdala (inhibitory avoidance), and in the lateral amygdala (conditioning to a tone). The circuitry involves, in addition, the pre- and infralimbic ventromedial prefrontal cortex, the central amygdala subnuclei, and the dentate gyrus. Fear learning models, notably inhibitory avoidance, have also been very useful for the analysis of the biochemical mechanisms of memory consolidation as a whole. These studies have capitalized on in vitro observations on long-term potentiation and other kinds of plasticity. The effect of a very large number of drugs on fear learning has been intensively studied, often as a prelude to the investigation of effects on anxiety. The extinction of fear learning involves to an extent a reversal of the flow of information in the mentioned structures and is used in the therapy of posttraumatic stress disorder and fear memories in general.
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Affiliation(s)
- Ivan Izquierdo
- National Institute of Translational Neuroscience, National Research Council of Brazil, and Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Cristiane R. G. Furini
- National Institute of Translational Neuroscience, National Research Council of Brazil, and Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Jociane C. Myskiw
- National Institute of Translational Neuroscience, National Research Council of Brazil, and Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
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Individual Differences in Anticipatory Somatosensory Cortex Activity for Shock is Positively Related with Trait Anxiety and Multisensory Integration. Brain Sci 2016; 6:brainsci6010002. [PMID: 26751483 PMCID: PMC4810172 DOI: 10.3390/brainsci6010002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 12/14/2015] [Accepted: 12/18/2015] [Indexed: 12/27/2022] Open
Abstract
Anxiety is associated with an exaggerated expectancy of harm, including overestimation of how likely a conditioned stimulus (CS+) predicts a harmful unconditioned stimulus (US). In the current study we tested whether anxiety-associated expectancy of harm increases primary sensory cortex (S1) activity on non-reinforced (i.e., no shock) CS+ trials. Twenty healthy volunteers completed a differential-tone trace conditioning task while undergoing fMRI, with shock delivered to the left hand. We found a positive correlation between trait anxiety and activity in right, but not left, S1 during CS+ versus CS− conditions. Right S1 activity also correlated with individual differences in both primary auditory cortices (A1) and amygdala activity. Lastly, a seed-based functional connectivity analysis demonstrated that trial-wise S1 activity was positively correlated with regions of dorsolateral prefrontal cortex (dlPFC), suggesting that higher-order cognitive processes contribute to the anticipatory sensory reactivity. Our findings indicate that individual differences in trait anxiety relate to anticipatory reactivity for the US during associative learning. This anticipatory reactivity is also integrated along with emotion-related sensory signals into a brain network implicated in fear-conditioned responding.
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26
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Kredlow MA, Unger LD, Otto MW. Harnessing reconsolidation to weaken fear and appetitive memories: A meta-analysis of post-retrieval extinction effects. Psychol Bull 2015; 142:314-36. [PMID: 26689086 DOI: 10.1037/bul0000034] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A new understanding of the mechanisms of memory retrieval and reconsolidation holds the potential for improving exposure-based treatments. Basic research indicates that following fear extinction, safety and fear memories may compete, raising the possibility of return of fear. One possible solution is to modify original fear memories through reconsolidation interference, reducing the likelihood of return of fear. Postretrieval extinction is a behavioral method of reconsolidation interference that has been explored in the context of conditioned fear and appetitive memory paradigms. This meta-analysis examines the magnitude of postretrieval extinction effects and potential moderators of these effects. A PubMed and PsycINFO search was conducted through June 2014. Sixty-three comparisons examining postretrieval extinction for preventing the return of fear or appetitive responses in animals or humans met inclusion criteria. Postretrieval extinction demonstrated a significant, small-to-moderate effect (g = .40) for further reducing the return of fear in humans and a significant, large effect (g = 0.89) for preventing the return of appetitive responses in animals relative to standard extinction. For fear outcomes in animals, effects were small (g = 0.21) and nonsignificant, but moderated by the number of animals housed together and the duration of time between postretrieval extinction/extinction and test. Across paradigms, these findings support the efficacy of this preclinical strategy for preventing the return of conditioned fear and appetitive responses. Overall, findings to date support the continued translation of postretrieval extinction research to human and clinical applications, with particular application to the treatment of anxiety, traumatic stress, and substance use disorders.
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Affiliation(s)
| | - Leslie D Unger
- Department of Psychological and Brain Sciences, Boston University
| | - Michael W Otto
- Department of Psychological and Brain Sciences, Boston University
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Brom M, Laan E, Everaerd W, Spinhoven P, Trimbos B, Both S. d-Cycloserine reduces context specificity of sexual extinction learning. Neurobiol Learn Mem 2015; 125:202-10. [PMID: 26456134 DOI: 10.1016/j.nlm.2015.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 09/07/2015] [Accepted: 09/28/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND d-Cycloserine (DCS) enhances extinction processes in animals. Although classical conditioning is hypothesized to play a pivotal role in the aetiology of appetitive motivation problems, no research has been conducted on the effect of DCS on the reduction of context specificity of extinction in human appetitive learning, while facilitation hereof is relevant in the context of treatment of problematic reward-seeking behaviors. METHODS Female participants were presented with two conditioned stimuli (CSs) that either predicted (CS+) or did not predict (CS-) a potential sexual reward (unconditioned stimulus (US); genital vibrostimulation). Conditioning took place in context A and extinction in context B. Subjects received DCS (125mg) or placebo directly after the experiment on day 1 in a randomized, double-blind, between-subject fashion (Placebo n=31; DCS n=31). Subsequent testing for CS-evoked conditioned responses (CRs) in both the conditioning (A) and the extinction context (B) took place 24h later on day 2. Drug effects on consolidation were then assessed by comparing the recall of sexual extinction memories between the DCS and the placebo groups. RESULTS Post learning administration of DCS facilitates sexual extinction memory consolidation and affects extinction's fundamental context specificity, evidenced by reduced conditioned genital and subjective sexual responses, relative to placebo, for presentations of the reward predicting cue 24h later outside the extinction context. CONCLUSIONS DCS makes appetitive extinction memories context-independent and prevents the return of conditioned response. NMDA receptor glycine site agonists may be potential pharmacotherapies for the prevention of relapse of appetitive motivation disorders with a learned component.
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Affiliation(s)
- Mirte Brom
- Institute of Psychology, Clinical Psychology Unit, Leiden University, Wassenaarseweg 52, 2333 AK, The Netherlands; Leiden University Medical Centre, Department of Psychosomatic Gynaecology & Sexology, VRSP, Rijnsburgerweg 10, Zone PG4-Z, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
| | - Ellen Laan
- Department of Sexology and Psychosomatic Obstetrics and Gynaecology, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
| | - Walter Everaerd
- Department Clinical Psychology, University of Amsterdam, Weesperplein 4, 1018 XA Amsterdam, The Netherlands.
| | - Philip Spinhoven
- Institute of Psychology, Clinical Psychology Unit, Leiden University, Wassenaarseweg 52, 2333 AK, The Netherlands; Department of Psychiatry, Leiden University Medical Centre, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
| | - Baptist Trimbos
- Leiden University Medical Centre, Department of Gynaecology, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
| | - Stephanie Both
- Leiden University Medical Centre, Department of Psychosomatic Gynaecology & Sexology, VRSP, Rijnsburgerweg 10, Zone PG4-Z, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
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Haaker J, Lonsdorf TB, Kalisch R. Effects of post-extinction l-DOPA administration on the spontaneous recovery and reinstatement of fear in a human fMRI study. Eur Neuropsychopharmacol 2015; 25:1544-55. [PMID: 26238968 DOI: 10.1016/j.euroneuro.2015.07.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 04/29/2015] [Accepted: 07/14/2015] [Indexed: 12/29/2022]
Abstract
Relapse is a pertinent problem in the treatment of anxiety disorders. In the laboratory, relapse is modeled as return of conditioned fear responses after successful fear extinction and is explained by insufficient retrieval and/or expression of the fear-inhibitory extinction memory that is generated during extinction learning. We have shown in mice and humans that return of fear can be prevented by administration of a single dose of the dopamine precursor l-3,4-dihydroxyphenylalanine (l-DOPA) immediately after extinction. In mice, this effect could be attributed to an enhancement of extinction memory consolidation. In our human study, we could not exclude that l-DOPA might have acted by interfering with the consolidation of the original fear memory. In the present study, we therefore used a combined differential cue and context conditioning paradigm where initial fear conditioning and extinction were conducted one day apart, in analogy to previous mouse studies. l-DOPA (N=21) or placebo (N=19) were administered after extinction, precluding any action on fear memory consolidation. In the return-of-fear test conducted one week later, drug effects on conditioned skin conductance responses were absent. However, we found evidence indicative of reduced neural activity, measured with functional magnetic resonance imaging (fMRI), in the l-DOPA group in areas related to conditioned fear and return of fear (amygdala, posterior hippocampus) and enhanced activity in a key area of extinction retrieval/expression (ventromedial prefrontal cortex), relative to placebo controls. These findings require further corroboration in additional experiments. Implications for further investigations on the role of the dopamine system in extinction and on the neuropharmacological augmentation of extinction-based therapies are discussed.
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Affiliation(s)
- Jan Haaker
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Karolinska Institutet, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Tina B Lonsdorf
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Raffael Kalisch
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Neuroimaging Center (NIC), Focus Program Translational Neuroscience, Johannes Gutenberg University Medical Center Mainz, Germany
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Hofmann SG, Carpenter JK, Otto MW, Rosenfield D, Smits JAJ, Pollack MH. Dose timing of D-cycloserine to augment cognitive behavioral therapy for social anxiety: Study design and rationale. Contemp Clin Trials 2015; 43:223-30. [PMID: 26111923 DOI: 10.1016/j.cct.2015.06.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 06/19/2015] [Accepted: 06/20/2015] [Indexed: 11/30/2022]
Abstract
The use of D-cycloserine (DCS) as a cognitive enhancer to augment exposure-based cognitive-behavioral therapy (CBT) represents a promising new translational research direction with the goal to accelerate and optimize treatment response for anxiety disorders. Some studies suggest that DCS may not only augment extinction learning but could also facilitate fear memory reconsolidation. Therefore, the effect of DCS may depend on fear levels reported at the end of exposure sessions. This paper presents the rationale and design for a randomized controlled trial examining the relative efficacy of tailoring DCS administration based on exposure success (i.e. end fear levels) during a 5-session group CBT protocol for social anxiety disorder (n = 156). Specifically, tailored post-session DCS administration will be compared against untailored post-session DCS, untailored pre-session DCS, and pill placebo in terms of reduction in social anxiety symptoms and responder status. In addition, a subset of participants (n = 96) will undergo a fear extinction retention experiment prior to the clinical trial in which they will be randomly assigned to receive either DCS or placebo prior to extinguishing a conditioned fear. The results from this experimental paradigm will clarify the mechanism of the effects of DCS on exposure procedures. This study aims to serve as the first step toward developing an algorithm for the personalized use of DCS during CBT for social anxiety disorder, with the ultimate goal of optimizing treatment outcome for anxiety disorders.
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Affiliation(s)
- Stefan G Hofmann
- Department of Psychological and Brain Sciences, Boston University, 648 Beacon Street, 6th, Floor Boston, MA 02215, United States.
| | - Joseph K Carpenter
- Department of Psychological and Brain Sciences, Boston University, 648 Beacon Street, 6th, Floor Boston, MA 02215, United States.
| | - Michael W Otto
- Department of Psychological and Brain Sciences, Boston University, 648 Beacon Street, 6th, Floor Boston, MA 02215, United States.
| | - David Rosenfield
- Department of Psychology, Southern Methodist Univeristy, Expressway Tower 1100N, Dallas, TX 75275, United States.
| | - Jasper A J Smits
- Department of Psychology, University of Texas at Austin, 108 E. Dean Keeton, Stop A8000, Austin, TX 78712, United States.
| | - Mark H Pollack
- Department of Psychiatry, Rush University Medical Center, 1645W. Jackson Blvd, Suite 600, Chicago, IL 60612, United States.
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Pace-Schott EF, Germain A, Milad MR. Sleep and REM sleep disturbance in the pathophysiology of PTSD: the role of extinction memory. BIOLOGY OF MOOD & ANXIETY DISORDERS 2015; 5:3. [PMID: 26034578 PMCID: PMC4450835 DOI: 10.1186/s13587-015-0018-9] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/12/2015] [Indexed: 01/04/2023]
Abstract
Post-traumatic stress disorder (PTSD) is accompanied by disturbed sleep and an impaired ability to learn and remember extinction of conditioned fear. Following a traumatic event, the full spectrum of PTSD symptoms typically requires several months to develop. During this time, sleep disturbances such as insomnia, nightmares, and fragmented rapid eye movement sleep predict later development of PTSD symptoms. Only a minority of individuals exposed to trauma go on to develop PTSD. We hypothesize that sleep disturbance resulting from an acute trauma, or predating the traumatic experience, may contribute to the etiology of PTSD. Because symptoms can worsen over time, we suggest that continued sleep disturbances can also maintain and exacerbate PTSD. Sleep disturbance may result in failure of extinction memory to persist and generalize, and we suggest that this constitutes one, non-exclusive mechanism by which poor sleep contributes to the development and perpetuation of PTSD. Also reviewed are neuroendocrine systems that show abnormalities in PTSD, and in which stress responses and sleep disturbance potentially produce synergistic effects that interfere with extinction learning and memory. Preliminary evidence that insomnia alone can disrupt sleep-dependent emotional processes including consolidation of extinction memory is also discussed. We suggest that optimizing sleep quality following trauma, and even strategically timing sleep to strengthen extinction memories therapeutically instantiated during exposure therapy, may allow sleep itself to be recruited in the treatment of PTSD and other trauma and stress-related disorders.
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Affiliation(s)
- Edward F. Pace-Schott
- />Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital—East, CNY 149 13th Street Room 2624, Charlestown, MA 02129 USA
| | - Anne Germain
- />Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA USA
| | - Mohammed R. Milad
- />Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital—East, CNY 149 13th Street Room 2624, Charlestown, MA 02129 USA
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Risbrough VB, Glenn DE, Baker DG. On the Road to Translation for PTSD Treatment: Theoretical and Practical Considerations of the Use of Human Models of Conditioned Fear for Drug Development. Curr Top Behav Neurosci 2015; 28:173-96. [PMID: 27311760 DOI: 10.1007/7854_2015_5010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The use of quantitative, laboratory-based measures of threat in humans for proof-of-concept studies and target development for novel drug discovery has grown tremendously in the last 2 decades. In particular, in the field of posttraumatic stress disorder (PTSD), human models of fear conditioning have been critical in shaping our theoretical understanding of fear processes and importantly, validating findings from animal models of the neural substrates and signaling pathways required for these complex processes. Here, we will review the use of laboratory-based measures of fear processes in humans including cued and contextual conditioning, generalization, extinction, reconsolidation, and reinstatement to develop novel drug treatments for PTSD. We will primarily focus on recent advances in using behavioral and physiological measures of fear, discussing their sensitivity as biobehavioral markers of PTSD symptoms, their response to known and novel PTSD treatments, and in the case of d-cycloserine, how well these findings have translated to outcomes in clinical trials. We will highlight some gaps in the literature and needs for future research, discuss benefits and limitations of these outcome measures in designing proof-of-concept trials, and offer practical guidelines on design and interpretation when using these fear models for drug discovery.
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Affiliation(s)
- Victoria B Risbrough
- Center of Excellence for Stress and Mental Health, San Diego, VA, USA. .,Department of Psychiatry, University of California San Diego, 9500 Gilman Dr. MC0804, La Jolla, San Diego, CA, 92093, USA.
| | - Daniel E Glenn
- Center of Excellence for Stress and Mental Health, San Diego, VA, USA
| | - Dewleen G Baker
- Center of Excellence for Stress and Mental Health, San Diego, VA, USA.,Department of Psychiatry, University of California San Diego, 9500 Gilman Dr. MC0804, La Jolla, San Diego, CA, 92093, USA
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De novo fear conditioning across diagnostic groups in the affective disorders: evidence for learning impairments. Behav Ther 2014; 45:619-29. [PMID: 25022773 PMCID: PMC4603557 DOI: 10.1016/j.beth.2013.12.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 12/23/2013] [Accepted: 12/26/2013] [Indexed: 01/20/2023]
Abstract
De novo fear conditioning paradigms have served as a model for how clinical anxiety may be acquired and maintained. To further examine variable findings in the acquisition and extinction of fear responses between clinical and nonclinical samples, we assessed de novo fear conditioning outcomes in outpatients with either anxiety disorders or depression and healthy subjects recruited from the community. Overall, we found evidence for attenuated fear conditioning, as measured by skin conductance, among the patient sample, with significantly lower fear acquisition among patients with depression and posttraumatic stress disorder. These acquisition deficits were evident in both the simple (considering the CS+only) and differential (evaluating the CS+in relation to the CS-) paradigms. Examination of extinction outcomes were hampered by the low numbers of patients who achieved adequate conditioning, but the available data indicated slower extinction among the patient, primarily panic disorder, sample. Results are interpreted in the context of the cognitive deficits that are common to the anxiety and mood disorders, with attention to a range of potential factors, including mood comorbidity, higher-and lower-order cognitive processes and deficits, and medication use, that may modulate outcomes in fear conditioning studies, and, potentially, in exposure-based cognitive behavioral therapy.
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33
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Emotions and cognitions: a critique of the dichotomous view of mental function. Am J Psychoanal 2014; 74:250-61. [PMID: 25117783 DOI: 10.1057/ajp.2014.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many approaches to the psyche, models of therapy, and neuroscience tend to view emotional and cognitive brain functions as separate entities. Such a focus on one of these two aspects of mental function, at times comes at the expense of ignoring the other. In this paper emotions and cognitions, along with perceptions and other elements of the internal and external contexts, are viewed as relevant vectors in a matrix of information. Through the processes of pattern completion and noise reduction, information in each of these vectors may evoke memories in the same or other vectors that are used in the formation of a subjective understanding of each experience. The important roles of the external (physical, temporal, relevant events, etc.) and internal (emotional, affective, hormonal, medications, etc.) contexts in the formation of such subjective experiences will be discussed. The use of this view in broader and more comprehensive psychotherapeutic approaches and combined pharmacological and psychological treatment is explored.
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Peters J, Pattij T, De Vries TJ. Targeting cocaine versus heroin memories: divergent roles within ventromedial prefrontal cortex. Trends Pharmacol Sci 2013; 34:689-95. [PMID: 24182624 DOI: 10.1016/j.tips.2013.10.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/01/2013] [Accepted: 10/03/2013] [Indexed: 10/26/2022]
Abstract
In the search for novel treatments for addiction, most research has been propelled by the hope for a 'magic bullet' that would cure all forms of addiction. More recently, the field has started to appreciate the differences between psychostimulants versus opiates. Recent data suggest that the ventromedial prefrontal cortex (vmPFC) may fundamentally serve different roles in cocaine versus heroin addiction: acting as a neural OFF switch for cocaine seeking, but an ON switch for heroin seeking. We discuss the relevance of this distinction in relationship to three main functions of the vmPFC: (i) extinction memory, (ii) the suppression of impulsive behaviors, and (iii) the transition from goal-directed behaviors to habits. We highlight the importance of dopamine in modulating corticostriatal circuits for each of these functions. Finally, we conclude by discussing the implications for treatment strategies.
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Affiliation(s)
- Jamie Peters
- Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University Medical Center, 1081 BT, Amsterdam, The Netherlands.
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35
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Wangelin BC, Powers MB, Smits JAJ, Tuerk PW. Enhancing exposure therapy for PTSD with yohimbine HCL: protocol for a double-blind, randomized controlled study implementing subjective and objective measures of treatment outcome. Contemp Clin Trials 2013; 36:319-26. [PMID: 23939512 DOI: 10.1016/j.cct.2013.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/30/2013] [Accepted: 08/03/2013] [Indexed: 02/06/2023]
Abstract
Prolonged exposure (PE) therapy is considered a gold standard protocol for the treatment of PTSD, and it is associated with large treatment effect sizes in combat veteran samples. However, considering high rates of PTSD in the present veteran population, ongoing research work is important toward improving treatment efficiency by decreasing time to symptom amelioration and increasing the amount of symptom amelioration. The proposed research aims to enhance exposure therapy outcomes for veterans with PTSD via combination treatment with PE and yohimbine hydrochloride (HCL), an alpha-2 adrenergic receptor antagonist. The proposed investigation entails a randomized, placebo-controlled trial investigating the effect of a single administration of yohimbine HCL (paired with the first session of imaginal exposure) on outcome of PE in 40 veterans with PTSD. An additional goal is to establish a pragmatic method of tracking psychophysiological measures over the course of therapy for incorporation into future clinical psychotherapy trials. Thus, in addition to traditional self- and clinician-reported psychological outcomes, heart rate and skin conductance reactivity will be measured during a standard trauma-specific imagery task before, during, and after PE treatment. We will further investigate whether changes in psychophysiological measures predict changes in patient- and clinician-reported outcome measures.
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Affiliation(s)
- Bethany C Wangelin
- Mental Health Service Line, Ralph H. Johnson Veterans Affairs Medical Center, 109 Bee St., Charleston, SC, United States; Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, 67 President St., Charleston, SC 29401, United States.
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Boddez Y, Baeyens F, Luyten L, Vansteenwegen D, Hermans D, Beckers T. Rating data are underrated: validity of US expectancy in human fear conditioning. J Behav Ther Exp Psychiatry 2013. [PMID: 23207968 DOI: 10.1016/j.jbtep.2012.08.003] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND AND OBJECTIVES Human fear conditioning is widely regarded as one of the prime paradigms for the study of fear and anxiety disorders. We provide an evaluation of a commonly used subjective measure in the human fear conditioning paradigm, namely the US-expectancy measurement. METHODS We assess the validity of US-expectancy with respect to conditions of pathological fear and anxiety using four established criteria for scrutiny of a laboratory test or model (i.e., face validity, diagnostic validity, predictive validity, construct validity). RESULTS Arguably, there is sufficient evidence for the face validity, diagnostic validity, predictive validity and construct validity of the US-expectancy measure. LIMITATIONS Presumed limitations of the US-expectancy measure, including its susceptibility to experimental demand and memory bias, are discussed. CONCLUSIONS The US-expectancy measure is a valuable measurement method that can be effectively used in research that aims to enhance our understanding of fear and anxiety disorders.
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Cannabidiol enhances consolidation of explicit fear extinction in humans. Psychopharmacology (Berl) 2013; 226:781-92. [PMID: 23307069 DOI: 10.1007/s00213-012-2955-y] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 12/06/2012] [Indexed: 12/16/2022]
Abstract
RATIONALE Whilst Cannabidiol (CBD), a non-psychotomimetic cannabinoid, has been shown to enhance extinction learning in rats, its effects on fear memory in humans have not previously been studied. OBJECTIVES We employed a Pavlovian fear-conditioning paradigm in order to assess the effects of CBD on extinction and consolidation. METHOD Forty-eight participants were conditioned to a coloured box (CS) with electric shocks (UCS) in one context and were extinguished in a second context. Participants received 32 mg of CBD either following before or after extinction in a double-blind, placebo-controlled design. At recall, 48 h later, participants were exposed to CSs and conditioning contexts before (recall) and after (reinstatement) exposure to the UCS. Skin conductance and shock expectancy measures of conditioned responding were recorded throughout. RESULTS Successful conditioning, extinction and recall were found in all three treatment groups. CBD given post-extinction enhanced consolidation of extinction learning as assessed by shock expectancy. CBD administered at either time produced trend level reduction in reinstatement of autonomic contextual responding. No acute effects of CBD were found on extinction. CONCLUSIONS These findings provide the first evidence that CBD can enhance consolidation of extinction learning in humans and suggest that CBD may have potential as an adjunct to extinction-based therapies for anxiety disorders.
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Cornwell BR, Overstreet C, Krimsky M, Grillon C. Passive avoidance is linked to impaired fear extinction in humans. Learn Mem 2013; 20:164-9. [PMID: 23427168 DOI: 10.1101/lm.028902.112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Conventional wisdom dictates we must face our fears to conquer them. This idea is embodied in exposure-based treatments for anxiety disorders, where the intent of exposure is to reverse a history of avoidant behavior that is thought to fuel a patient's irrational fears. We tested in humans the relationship between fear and avoidance by combining Pavlovian differential fear conditioning with a novel task for quantifying spontaneous passive avoidant behavior. During self-guided navigation in virtual reality following de novo fear conditioning, we observed participants keeping their distance from the feared object. At the individual level, passive avoidant behavior was highly associated with maladaptive fear expression (fear-potentiated startle) during late extinction training, indicating that extinction learning was impaired following a brief episode of avoidance. Avoidant behavior, however, was not related to initial acquired fear, raising doubt about a straightforward link between physiological fear and behavioral avoidance. We conclude that a deeper understanding of what motivates avoidance may offer a target for early intervention, before fears transition from the rational to the irrational.
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Affiliation(s)
- Brian R Cornwell
- Section on Neurobiology of Fear and Anxiety, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
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39
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Tart CD, Handelsman PR, Deboer LB, Rosenfield D, Pollack MH, Hofmann SG, Powers MB, Otto MW, Smits JAJ. Augmentation of exposure therapy with post-session administration of D-cycloserine. J Psychiatr Res 2013; 47:168-74. [PMID: 23098672 PMCID: PMC3732105 DOI: 10.1016/j.jpsychires.2012.09.024] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 09/26/2012] [Accepted: 09/27/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pre-session administration of d-cycloserine (DCS) has been found to augment exposure therapy outcomes in a variety of anxiety disorders. To be able to enhance learning only for successful exposure sessions, it would be beneficial to have the option of administering DCS after rather than before the session, a strategy encouraged by pre-clinical work. We believe the present study is the first published report on the efficacy of post-session administration of DCS in humans. METHOD Adults (N = 29) with a DSM-IV diagnosis of acrophobia were randomized to receive two sessions of virtual reality exposure therapy (VRE) in combination with placebo or 50 mg of DCS. Instead of administering the pill prior to each of the sessions, as has been done in extant work, we administered the pill immediately following each session. Measures of acrophobia severity were collected at baseline, at each treatment session, 1-week post-treatment, and at 1-month follow-up. RESULTS Mixed-effects repeated-measures ANOVAs and GLMMs revealed significant improvement in all outcome measures over time, but no between-group differences were observed. At post-treatment, 63.5% of patients in the placebo condition vs. 60.0% of those in the DCS condition were in remission. At 1-month follow up, 63.4% of those in the placebo condition vs. 66.6% of those in the DCS condition were in remission. CONCLUSIONS These findings do not support the application of post-session DCS administration for augmenting the efficacy of exposure-based treatments. Possible reasons for these findings are discussed. TRIAL REGISTRY The Trial is registered at ClinicalTrials.gov (NCT01102803).
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Affiliation(s)
- Candyce D Tart
- Department of Psychology, Southern Methodist University, USA.
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40
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Cleren C, Tallarida I, Guiniec EL, Janin F, Nachon O, Canini F, Spennato G, Moreau JL, Garcia R. Low-frequency stimulation of the ventral hippocampus facilitates extinction of contextual fear. Neurobiol Learn Mem 2013; 101:39-45. [PMID: 23298787 DOI: 10.1016/j.nlm.2012.12.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 12/23/2012] [Accepted: 12/30/2012] [Indexed: 11/27/2022]
Abstract
Difficulties to treat fear-associated disorders, including posttraumatic stress disorder, are thought to result from dysfunction in fear extinction learning and/or memory. Animal studies on extinction modulation are therefore promising for the development of new treatments. Recent rat studies, including ones using low-frequency stimulation (LFS), have demonstrated that the ventral hippocampus (VH) modulates extinction memory. The present study explores whether the VH also modulates extinction learning. For this, rats were implanted with stimulating electrodes in the VH and experienced contextual fear conditioning, followed 6 or 24 h later by VH LFS and three sessions of extinction training. We found that, whatever the delay used (6 or 24 h), animals that received VH LFS displayed persistent low levels of freezing from the second extinction session, whereas control rats showed low levels of freezing only during the third session. In animals submitted to a stress condition (provoked by a single inescapable foot-shock followed by three sessions of situational reminders) prior to fear conditioning, VH LFS also reduced freezing levels, which, in contrast, remained high in control rats during the course of extinction training. These data suggest that LFS, targeting the VH, may be useful in reducing fear responses during extinction learning.
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Affiliation(s)
- Carine Cleren
- Institut de Neurosciences de la Timone, UMR 7289, Aix-Marseille Université & CNRS, 13385 Marseille, France.
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d-Cycloserine administered directly to infralimbic medial prefrontal cortex enhances extinction memory in sucrose-seeking animals. Neuroscience 2013; 230:24-30. [DOI: 10.1016/j.neuroscience.2012.11.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 11/01/2012] [Accepted: 11/03/2012] [Indexed: 01/13/2023]
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Translational approaches to the treatment of anxiety disorders. Transl Neurosci 2012. [DOI: 10.1017/cbo9780511980053.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Myers KM, Carlezon WA. D-cycloserine effects on extinction of conditioned responses to drug-related cues. Biol Psychiatry 2012; 71:947-55. [PMID: 22579305 PMCID: PMC4001849 DOI: 10.1016/j.biopsych.2012.02.030] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 02/14/2012] [Accepted: 02/18/2012] [Indexed: 11/26/2022]
Abstract
D-cycloserine (DCS) is an N-methyl-D-aspartate (NMDA) receptor partial agonist that facilitates extinction of conditioned fear in animals and cue exposure therapy (CET) for fear and anxiety disorders in people. Recent preclinical and clinical studies have examined the effect of DCS on extinction of conditioned responses elicited by cues paired with administration of or withdrawal from drugs of abuse, including physiological responses, craving, withdrawal, and drug-seeking behavior. DCS facilitates extinction and blunts postextinction recovery of these responses in animal models, including place conditioning and drug self-administration, but DCS effects on CET in substance users/abusers are less robust. Some of the null effects in the clinical literature might be attributable to issues related to sample size, data characteristics, DCS administration, and participant characteristics, among others. In this review we describe the preclinical and clinical literatures on DCS modulation of extinction of addiction-related conditioned responses, consider possible limitations of the clinical studies that have been published to date, and propose ways of designing future clinical studies so as to maximize the probability of detecting a DCS effect. We also discuss concerns with regard to potential harmful effects of DCS-coupled CET in addicts and describe how these concerns might be mitigated. We conclude that it is as yet unclear whether DCS-coupled CET might be a useful approach in the treatment of addiction.
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Klumpers F, Denys D, Kenemans JL, Grillon C, van der Aart J, Baas JMP. Testing the effects of Δ9-THC and D-cycloserine on extinction of conditioned fear in humans. J Psychopharmacol 2012; 26:471-8. [PMID: 22351380 PMCID: PMC3454470 DOI: 10.1177/0269881111431624] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Preclinical evidence implicates several neurotransmitter systems in the extinction of conditioned fear. These results are of great interest, because the reduction of acquired fear associations is critical in therapies for anxiety disorders. We tested whether findings with respect to the N-methyl-D-aspartate (NMDA) and cannabinoid receptor (CB) systems in animals carry over to healthy human subjects. To that end, we administered selected doses of D-cycloserine (partial NMDA receptor agonist, 250 mg), delta-9-tetrahydrocannabinol (THC, CB(1) receptor agonist, 10 mg), or placebo prior to the extinction session of a 3-day conditioning protocol. D-cycloserine did not affect within-session extinction, or the retention of extinction in healthy human participants, in contrast with patient data but in line with previous reports in healthy volunteers. During extinction training, Δ9-THC reduced conditioned skin conductance responses, but not fear-potentiated startle. This effect was not retained at the retention test 2 days later, suggesting it was dependent on acute effects of the drug. Our findings implicate that facilitation of the CB(1) or NMDA system with the substances used in this study does not affect conditioned fear extinction lastingly in healthy humans. The apparent discrepancy between these findings and the results from (pre-)clinical trials is discussed in terms of room for improvement in these systems in healthy volunteers, and the lack of specificity of THC as a CB(1) agonist.
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Affiliation(s)
- Floris Klumpers
- Experimental Psychology and Helmholtz Institute, Utrecht University, Utrecht, the Netherlands
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Davis M. NMDA receptors and fear extinction: implications for cognitive behavioral therapy. DIALOGUES IN CLINICAL NEUROSCIENCE 2012. [PMID: 22275851 PMCID: PMC3263393 DOI: 10.31887/dcns.2011.13.4/mdavis] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Based primarily on studies that employ Pavlovian fear conditioning, extinction of conditioned fear has been found to be mediated by N-methyl-D-aspartate (NMDA) receptors in the amygdala and medial prefrontal cortex. This led to the discovery that an NMDA partial agonist, D-cycloserine, could facilitate fear extinction when given systemically or locally into the amygdala. Because many forms of cognitive behavioral therapy depend on fear extinction, this led to the successful use of D-cycloserine as an adjunct to psychotherapy in patients with so-called simple phobias (fear of heights), social phobia, obsessive-compulsive behavior, and panic disorder. Data in support of these conclusions are reviewed, along with some of the possible limitations of D-cycloserine as an adjunct to psychotherapy.
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Affiliation(s)
- Michael Davis
- Emory University, Yerkes National Primate Center and the Center for Behavioral Neuroscience, Atlanta, Georgia, USA.
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Abstract
Over the last few years, neuroimaging techniques have contributed greatly to the identification of the structural and functional neuroanatomy of anxiety disorders. The amygdala seems to be a crucial structure for fear and anxiety, and has consistently been found to be activated in anxiety-provoking situations. Apart from the amygdala, the insula and anterior cinguiate cortex seem to be critical, and all three have been referred to as the “fear network.” In the present article, we review the main findings from three major lines of research. First, we examine human models of anxiety disorders, including fear conditioning studies and investigations of experimentally induced panic attacks. Then we turn to research in patients with anxiety disorders and take a dose look at post-traumatic stress disorder and obsessive-compulsive disorder. Finally, we review neuroimaging studies investigating neural correlates of successful treatment of anxiety, focusing on exposure-based therapy and several pharmacological treatment options, as well as combinations of both.
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Affiliation(s)
- Kathrin Holzschneider
- University Medical Center Hamburg-Eppendorf, Department of Psychiatry and Psychotherapy, Psychiatry Neuroimaging Branch, Hamburg, Germany
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Abstract
Alterations in neurodevelopment are thought to modify risk of numerous psychiatric disorders, including schizophrenia, autism, ADHD, mood and anxiety disorders, and substance abuse. However, little is known about the cellular and molecular changes that guide these neurodevelopmental changes and how they contribute to mental illness. In this review, we suggest that elucidating this process in humans requires the use of model organisms. Furthermore, we advocate that such translational work should focus on the role that genes and/or environmental factors play in the development of circuits that regulate specific physiological and behavioral outcomes in adulthood. This emphasis on circuit development, as a fundamental unit for understanding behavior, is distinct from current approaches of modeling psychiatric illnesses in animals in two important ways. First, it proposes to replace the diagnostic and statistical manual of mental disorders (DSM) diagnostic system with measurable endophenotypes as the basis for modeling human psychopathology in animals. We argue that a major difficulty in establishing valid animal models lies in their reliance on the DSM/International Classification of Diseases conceptual framework, and suggest that the Research Domain Criteria project, recently proposed by the NIMH, provides a more suitable system to model human psychopathology in animals. Second, this proposal emphasizes the developmental origin of many (though clearly not all) psychiatric illnesses, an issue that is often glossed over in current animal models of mental illness. We suggest that animal models are essential to elucidate the mechanisms by which neurodevelopmental changes program complex behavior in adulthood. A better understanding of this issue, in animals, is the key for defining human psychopathology, and the development of earlier and more effective interventions for mental illness.
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Kuriyama K, Honma M, Soshi T, Fujii T, Kim Y. Effect of D-cycloserine and valproic acid on the extinction of reinstated fear-conditioned responses and habituation of fear conditioning in healthy humans: a randomized controlled trial. Psychopharmacology (Berl) 2011; 218:589-97. [PMID: 21594560 DOI: 10.1007/s00213-011-2353-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 05/05/2011] [Indexed: 11/30/2022]
Abstract
RATIONALE Although the effects of D: -cycloserine (DCS) and valproic acid (VPA) on the facilitation of the extinction of fear-conditioned memory have been elucidated in animals, these effects have not been clearly confirmed in humans. OBJECTIVE This study aimed to determine the effect of DCS (100 mg) and VPA (400 mg) on the facilitation of the extinction and acquisition of fear-conditioned memory in humans. METHODS We performed a randomized, blind, placebo-controlled, four-arm clinical trial in 60 healthy adults. Visual cues and electric shocks were used as the conditioned stimulus (CS) and unconditioned stimulus (US), respectively. RESULTS The extinction or acquisition effect was not observed in the simple recall after the extinction or acquisition of coupled CS-US; however, the extinction and habituation effects but not the acquisition effects were presented after the unexpected re-exposure of coupled CS-US (reinstatement stimuli). Extinction and habituation effects were facilitated by either a single dose of DCS or VPA or a combination of DCS and VPA. However, we did not observe the expected synergistic effect of the combined treatment on the extinction or habituation of fear conditioning. CONCLUSION A single dose of DCS or VPA might enhance exposure-based cognitive therapy of anxiety disorders by reducing the vulnerability to reinstatement and preventing relapses of fear-conditioned responses.
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Affiliation(s)
- Kenichi Kuriyama
- Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
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Ayers LW, Missig G, Schulkin J, Rosen JB. Oxytocin reduces background anxiety in a fear-potentiated startle paradigm: peripheral vs central administration. Neuropsychopharmacology 2011; 36:2488-97. [PMID: 21796104 PMCID: PMC3194076 DOI: 10.1038/npp.2011.138] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 06/23/2011] [Accepted: 06/23/2011] [Indexed: 12/21/2022]
Abstract
Oxytocin is known to have anti-anxiety and anti-stress effects. Using a fear-potentiated startle paradigm in rats, we previously demonstrated that subcutaneously administered oxytocin suppressed acoustic startle following fear conditioning compared with startle before fear conditioning (termed background anxiety), but did not have an effect on cue-specific fear-potentiated startle. The findings suggest oxytocin reduces background anxiety, an anxious state not directly related to cue-specific fear, but sustained beyond the immediate threat. The goal of the present study was to compare the effects of centrally and peripherally administered oxytocin on background anxiety and cue-specific fear. Male rats were given oxytocin either subcutaneously (SC) or intracerebroventricularly (ICV) into the lateral ventricles before fear-potentiated startle testing. Oxytocin doses of 0.01 and 0.1 μg/kg SC reduced background anxiety. ICV administration of oxytocin at doses from 0.002 to 20 μg oxytocin had no effect on background anxiety or cue-specific fear-potentiated startle. The 20 μg ICV dose of oxytocin did reduce acoustic startle in non-fear conditioned rats. These studies indicate that oxytocin is potent and effective in reducing background anxiety when delivered peripherally, but not when delivered into the cerebroventricular system. Oxytocin given systemically may have anti-anxiety properties that are particularly germane to the hypervigilance and exaggerated startle typically seen in many anxiety and mental health disorder patients.
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Affiliation(s)
- Luke W Ayers
- Department of Psychology, Behavioral Neuroscience Program, University of Delaware, Newark, DE, USA
| | - Galen Missig
- Neuroscience Graduate Program, University of Vermont, Burlington, VT, USA
| | - Jay Schulkin
- Department of Neuroscience, Georgetown University, Washington, DC, USA
- Behavioral Endocrinology Section, National Institute of Mental Health, Washington, DC, USA
- Research Department, American College of Obstetricians and Gynecologists, Washington, DC, USA
| | - Jeffrey B Rosen
- Department of Psychology, Behavioral Neuroscience Program, University of Delaware, Newark, DE, USA
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