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Tekampe J, van Middendorp H, Biermasz NR, Sweep FCGJ, Meijer OC, Pelsma ICM, Pereira AM, Hermus ARMM, Evers AWM. Conditioning cortisol in healthy young women - A randomized controlled trial. Psychoneuroendocrinology 2021; 124:105081. [PMID: 33340878 DOI: 10.1016/j.psyneuen.2020.105081] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Learned placebo effects induced by pharmacological conditioning affect immune and endocrine outcomes and may offer new possibilities for clinical applications. Whether or not cortisol is subject to this type of associative learning processes, and whether conditioning may affect responses to stress, is currently unclear. METHOD A randomized placebo-controlled trial was conducted in 48 healthy young women. During acquisition, participants received a pill containing either 100 mg hydrocortisone (unconditioned stimulus) or placebo, paired with a gustatory conditioned stimulus on three consecutive days. During evocation, all participants received placebo paired with the conditioned stimulus, again on three consecutive days. During the third evocation trial, participants underwent a psychosocial stress task. The main outcome parameter salivary cortisol and secondary outcome parameters salivary alpha-amylase, self-reported positive affect and tension, heart rate, and skin conductance level were measured at several time points. RESULTS Significant baseline group differences on cortisol were found at several time points, which complicate the interpretation of group differences. During the first evocation session, the conditioned group showed a moderately smaller cumulative decrease in salivary cortisol from baseline than the placebo control group. No significant differences were found between the groups on cortisol during the second and third evocation or in response to stress, nor on other outcome measures. CONCLUSION Although the results provide potential further indications for effects of conditioning on cortisol, baseline differences make it impossible to draw clear conclusions. No indications for possible effects of conditioning on the cortisol stress response or autonomous or affective responses to stress were found.
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Affiliation(s)
- Judith Tekampe
- Heath Medical and Neuropsychology Unit, Leiden University, Leiden, The Netherlands; Department of Medical Psychology, Radboud University Medical Center, Nijmegen, The Netherlands.
| | | | - Nienke R Biermasz
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Center for Endocrine Tumors Leiden (CETL), Leiden University Medical Center, The Netherlands.
| | - Fred C G J Sweep
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Onno C Meijer
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Center for Endocrine Tumors Leiden (CETL), Leiden University Medical Center, The Netherlands.
| | - Iris C M Pelsma
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Center for Endocrine Tumors Leiden (CETL), Leiden University Medical Center, The Netherlands.
| | - Alberto M Pereira
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Center for Endocrine Tumors Leiden (CETL), Leiden University Medical Center, The Netherlands.
| | - Ad R M M Hermus
- Division of Endocrinology, Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Andrea W M Evers
- Heath Medical and Neuropsychology Unit, Leiden University, Leiden, The Netherlands; Department of Medical Psychology, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands.
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Lückemann L, Stangl H, Straub RH, Schedlowski M, Hadamitzky M. Learned Immunosuppressive Placebo Response Attenuates Disease Progression in a Rodent Model of Rheumatoid Arthritis. Arthritis Rheumatol 2020; 72:588-597. [PMID: 31509354 DOI: 10.1002/art.41101] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Patients with chronic inflammatory autoimmune diseases benefit from a broad spectrum of immunosuppressive and antiproliferative medication available today. However, nearly all of these therapeutic compounds have unwanted toxic side effects. Recent knowledge about the neurobiology of placebo responses indicates that associative learning procedures can be utilized for dose reduction in immunopharmacotherapy while simultaneously maintaining treatment efficacy. This study was undertaken to examine whether and to what extent a 75% reduction of pharmacologic medication in combination with learned immunosuppression affects the clinical outcome in a rodent model of type II collagen-induced arthritis. METHODS An established protocol of taste-immune conditioning was applied in a disease model of chronic inflammatory autoimmune disease (type II collagen-induced arthritis) in rats, where a novel taste (saccharin; conditioned stimulus [CS]) was paired with an injection of the immunosuppressive drug cyclosporin A (CSA) (unconditioned stimulus [US]). Following conditioning with 3 CS/US pairings (acquisition), the animals were immunized with type II collagen and Freund's incomplete adjuvant. Fourteen days later, at the first occurrence of clinical symptoms, retrieval was started by presenting the CS together with low-dose CSA as reminder cues to prevent the conditioned response from being extinguished. RESULTS This "memory-updating" procedure stabilized the learned immune response and significantly suppressed disease progression in immunized rats. Clinical arthritis score and histologic inflammatory symptoms (both P < 0.05) were significantly diminished by learned immunosuppression in combination with low-dose CSA (25% of the full therapeutic dose) via β-adrenoceptor-dependent mechanisms, to the same extent as with full-dose (100%) pharmacologic treatment. CONCLUSION These results indicate that learned immunosuppression appears to be mediated via β-adrenoceptors and might be beneficial as a supportive regimen in the treatment of chronic inflammatory autoimmune diseases by diminishing disease exacerbation.
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Affiliation(s)
- Laura Lückemann
- University Hospital Essen and University of Duisburg-Essen, Essen, Germany
| | | | | | | | - Martin Hadamitzky
- University Hospital Essen and University of Duisburg-Essen, Essen, Germany
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Frumkin K. Behavioral Conditioning, the Placebo Effect, and Emergency Department Pain Management. J Emerg Med 2020; 59:303-310. [PMID: 32451185 DOI: 10.1016/j.jemermed.2020.04.025] [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: 12/22/2019] [Revised: 03/26/2020] [Accepted: 04/08/2020] [Indexed: 10/24/2022]
Abstract
Animals and humans can be readily conditioned to associate a novel stimulus (often a unique taste) by pairing it with the effects of a drug or other agent. When later presented with the stimulus alone, their body's systems respond as if the drug or agent were given. The earliest clinical applications demonstrated both conditioned suppression and enhancement of immune processes. Unique benign stimuli, paired with chemotherapy, come to elicit T-cell suppression when administered alone. The beneficial immune responses to an antigen can be conditioned in the same manner. Further study of what came to be called "psychoneuroimmunology" led to the understanding that the familiar placebo effect, previously attributed to suggestion and expectation, is at least equally dependent on the same sorts of behavioral conditioning. The demonstrated ability to manipulate the immune system by a conditioned taste stimulus is, by definition, a placebo: a therapeutic effect caused by an inactive agent. The purpose of this analysis was to stimulate research in, and the application of, placebo-response conditioning to emergency medicine. Clinical and experimental studies confirm the usefulness of conditioned placebos in analgesia and in placebo-controlled dose reduction. Such conditioning paradigms demonstrate "one-trial learning," making them potentially useful in pain and addiction management within a single emergency department encounter.
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Affiliation(s)
- Kenneth Frumkin
- Emergency Medicine Department, Naval Medical Center, Portsmouth, Virginia
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Smits RM, Veldhuijzen DS, van Middendorp H, Hissink Muller PCE, Armbrust W, Legger E, Wulffraat NM, Evers AWM. Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance. Pediatr Rheumatol Online J 2020; 18:12. [PMID: 32033577 PMCID: PMC7006148 DOI: 10.1186/s12969-020-0407-5] [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: 10/16/2019] [Accepted: 02/03/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance. PRESENTATION OF THE HYPOTHESIS A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects. TESTING THE HYPOTHESIS This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists. IMPLICATIONS OF THE HYPOTHESIS Based on previous experimental and clinical findings of pharmacological conditioning with immune responses, we propose that the JIA patient group is particularly suited to benefit from a pharmacological conditioning design. Moreover, findings from this study may potentially also be promising for other patient groups that endure long-lasting drug therapies.
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Affiliation(s)
- Rosanne M. Smits
- 0000 0001 2312 1970grid.5132.5Health, Medical and Neuropsychology unit, Leiden University, Leiden, P.O. Box 9500, The Netherlands ,Leiden Institute for Brain and Cognition, Leiden, P.O. Box 9600, The Netherlands ,0000000090126352grid.7692.aDepartment Pediatric Rheumatology and Immunology, University Medical Center Utrecht, Utrecht, P.O. Box 85090, The Netherlands
| | - Dieuwke S. Veldhuijzen
- 0000 0001 2312 1970grid.5132.5Health, Medical and Neuropsychology unit, Leiden University, Leiden, P.O. Box 9500, The Netherlands ,Leiden Institute for Brain and Cognition, Leiden, P.O. Box 9600, The Netherlands ,0000000090126352grid.7692.aDepartment Pediatric Rheumatology and Immunology, University Medical Center Utrecht, Utrecht, P.O. Box 85090, The Netherlands
| | - Henriet van Middendorp
- 0000 0001 2312 1970grid.5132.5Health, Medical and Neuropsychology unit, Leiden University, Leiden, P.O. Box 9500, The Netherlands ,Leiden Institute for Brain and Cognition, Leiden, P.O. Box 9600, The Netherlands
| | - Petra C. E. Hissink Muller
- 0000000089452978grid.10419.3dDepartment Pediatric Rheumatology and Immunology, Leiden University Medical Center, Leiden, P.O. Box 9600, The Netherlands
| | - Wineke Armbrust
- 0000 0000 9558 4598grid.4494.dDepartment Pediatric Rheumatology and Immunology, University Medical Centre Groningen, Groningen, P.O. Box 30.001, The Netherlands
| | - Elizabeth Legger
- 0000 0000 9558 4598grid.4494.dDepartment Pediatric Rheumatology and Immunology, University Medical Centre Groningen, Groningen, P.O. Box 30.001, The Netherlands
| | - Nico M. Wulffraat
- 0000000090126352grid.7692.aDepartment Pediatric Rheumatology and Immunology, University Medical Center Utrecht, Utrecht, P.O. Box 85090, The Netherlands
| | - Andrea W. M. Evers
- 0000 0001 2312 1970grid.5132.5Health, Medical and Neuropsychology unit, Leiden University, Leiden, P.O. Box 9500, The Netherlands ,Leiden Institute for Brain and Cognition, Leiden, P.O. Box 9600, The Netherlands ,0000000089452978grid.10419.3dDepartment of Psychiatry, Leiden University Medical Center, Leiden, P.O. Box 9600, The Netherlands
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Hadamitzky M, Lückemann L, Pacheco-López G, Schedlowski M. Pavlovian Conditioning of Immunological and Neuroendocrine Functions. Physiol Rev 2020; 100:357-405. [DOI: 10.1152/physrev.00033.2018] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The phenomenon of behaviorally conditioned immunological and neuroendocrine functions has been investigated for the past 100 yr. The observation that associative learning processes can modify peripheral immune functions was first reported and investigated by Ivan Petrovic Pavlov and his co-workers. Their work later fell into oblivion, also because so little was known about the immune system’s function and even less about the underlying mechanisms of how learning, a central nervous system activity, could affect peripheral immune responses. With the employment of a taste-avoidance paradigm in rats, this phenomenon was rediscovered 45 yr ago as one of the most fascinating examples of the reciprocal functional interaction between behavior, the brain, and peripheral immune functions, and it established psychoneuroimmunology as a new research field. Relying on growing knowledge about efferent and afferent communication pathways between the brain, neuroendocrine system, primary and secondary immune organs, and immunocompetent cells, experimental animal studies demonstrate that cellular and humoral immune and neuroendocrine functions can be modulated via associative learning protocols. These (from the classical perspective) learned immune responses are clinically relevant, since they affect the development and progression of immune-related diseases and, more importantly, are also inducible in humans. The increased knowledge about the neuropsychological machinery steering learning and memory processes together with recent insight into the mechanisms mediating placebo responses provide fascinating perspectives to exploit these learned immune and neuroendocrine responses as supportive therapies, the aim being to reduce the amount of medication required, diminishing unwanted drug side effects while maximizing the therapeutic effect for the patient’s benefit.
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Affiliation(s)
- Martin Hadamitzky
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Laura Lückemann
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Gustavo Pacheco-López
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
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Lückemann L, Unteroberdörster M, Martinez Gomez E, Schedlowski M, Hadamitzky M. Behavioral conditioning of anti-proliferative and immunosuppressive properties of the mTOR inhibitor rapamycin. Brain Behav Immun 2019; 79:326-331. [PMID: 30953772 DOI: 10.1016/j.bbi.2019.04.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 02/05/2019] [Accepted: 04/02/2019] [Indexed: 02/07/2023] Open
Abstract
Suppression of immune functions can be elicited by behavioral conditioning using drugs such as cyclosporine A, cyclophosphamide, or opioids. Nevertheless, little is known regarding the conditioned actions of clinically approved immunosuppressive drugs with distinct cell signaling pathways. The present study tested the assumption to condition immunopharmacological properties of rapamycin (sirolimus), a small-molecule drug widely used as anti-tumor medication and to prevent graft rejection. For this purpose, a conditioned taste avoidance (CTA) paradigm was used, pairing the presentation of a novel taste (saccharin) as conditioned stimulus (CS) with injections of rapamycin as unconditioned stimulus (US). Subsequent re-exposure to the CS at a later time revealed that conditioning with rapamycin induced an only moderate CTA. However, pronounced conditioned immunopharmacological effects were observed, reflected by significantly reduced levels of IL-10 cytokine production and diminished proliferation of splenic CD4+ and CD8+ T cells in Dark Agouti and Fischer 344 rats. For one, these findings support earlier observations revealing that not a pronounced CTA but rather re-exposure to the CS or taste itself is essential for conditioned immunosuppression. Moreover, our results provide first evidence that the phenomenon of learned immune responses generalizes across many, if not all, small-molecule drugs with immunosuppressive properties, thereby providing the basis for employing learned immunopharmacological strategies in clinical contexts such as supportive therapy.
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Affiliation(s)
- Laura Lückemann
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany
| | - Meike Unteroberdörster
- Department of Neurosurgery, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Elian Martinez Gomez
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Martin Hadamitzky
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany.
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Bąbel P. Classical Conditioning as a Distinct Mechanism of Placebo Effects. Front Psychiatry 2019; 10:449. [PMID: 31293460 PMCID: PMC6603292 DOI: 10.3389/fpsyt.2019.00449] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 06/06/2019] [Indexed: 11/16/2022] Open
Abstract
Classical conditioning was suggested as a mechanism of placebo effects in the 1950s. It was then challenged by response expectancy theory, which proposed that classical conditioning is just one of the means by which expectancies are acquired and changed. According to that account, placebo effects induced by classical conditioning are mediated by expectancies. However, in most of the previous studies, either expectancies were not measured or classical conditioning was combined with verbal suggestions. Thus, on the basis of those studies, it is not possible to conclude whether expectancies are involved in placebo effects induced by pure classical conditioning. Two lines of recent studies have challenged the idea that placebo effects induced by classical conditioning are always mediated by expectancies. First, some recent studies have shown that a hidden conditioning procedure elicits both placebo analgesia and nocebo hyperalgesia, neither of which is predicted by expectancy. Second, there are studies showing that visual cues paired with pain stimuli of high or low intensity induce both placebo analgesia and nocebo hyperalgesia when they are presented subliminally without participants' awareness. The results of both lines of studies suggest that expectancy may not always be involved in placebo effects induced by classical conditioning and that conditioning may be a distinct mechanism of placebo effects. Thus, these results support the idea that placebo effects can be learned by classical conditioning either consciously or unconsciously. However, the existing body of evidence is limited to classically conditioned placebo effects in pain, that is, placebo analgesia and nocebo hyperalgesia.
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Affiliation(s)
- Przemysław Bąbel
- Pain Research Group, Institute of Psychology, Jagiellonian University, Kraków, Poland
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Gano A, Pautassi RM, Doremus-Fitzwater TL, Barney TM, Vore AS, Deak T. Conditioning the neuroimmune response to ethanol using taste and environmental cues in adolescent and adult rats. Exp Biol Med (Maywood) 2019; 244:362-371. [PMID: 30808184 PMCID: PMC6488863 DOI: 10.1177/1535370219831709] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 01/28/2019] [Indexed: 11/16/2022] Open
Abstract
IMPACT STATEMENT A combined odor and taste cue was paired with a binge-like ethanol exposure (4 g/kg intraperitoneal) using a single-trial learning paradigm. Re-exposure to the CS alone was sufficient to evoke a conditioned Interleukin (IL)-6 elevation in the amygdala in adolescents, an effect that was not observed in young adults. This demonstrates a particular sensitivity of adolescents to alcohol-associated cues and neuroimmune learning, whereas prior work indicated that adults require multiple pairings of ethanol to the CS in order to achieve a conditioned amygdala IL-6 response. While the role of immune conditioning has been studied in other drugs of abuse, these findings highlight a previously unknown aspect of alcohol-related learning. Given the emergent importance of the neuroimmune system in alcohol abuse, these findings may be important for understanding cue-induced reinstatement of alcohol intake among problem drinkers.
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Affiliation(s)
- Anny Gano
- Department of Psychology, Developmental Exposure Alcohol
Research Center (DEARC), Behavioral Neuroscience Program, Binghamton University,
Binghamton, NY 13902-6000, USA
| | - Ricardo M Pautassi
- Instituto de Investigación Médica M. y M. Ferreyra
(INIMEC–CONICET-Universidad Nacional de Córdoba) and Facultad de Psicología,
UNC, Córdoba, CP 5000, Argentina
| | | | - Thaddeus M Barney
- Department of Psychology, Developmental Exposure Alcohol
Research Center (DEARC), Behavioral Neuroscience Program, Binghamton University,
Binghamton, NY 13902-6000, USA
| | - Andrew S Vore
- Department of Psychology, Developmental Exposure Alcohol
Research Center (DEARC), Behavioral Neuroscience Program, Binghamton University,
Binghamton, NY 13902-6000, USA
| | - Terrence Deak
- Department of Psychology, Developmental Exposure Alcohol
Research Center (DEARC), Behavioral Neuroscience Program, Binghamton University,
Binghamton, NY 13902-6000, USA
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Affiliation(s)
- Teun van Gelder
- Department of Hospital Pharmacy, Erasmus MC, University Medical Center Rotterdam, the Netherlands.,Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, The Netherlands
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Puviani L, Rama S. Understanding and exploiting prediction errors minimization within the brain in pharmacological treatments. Behav Brain Res 2018; 359:223-233. [PMID: 30395877 DOI: 10.1016/j.bbr.2018.10.019] [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: 07/19/2018] [Revised: 10/14/2018] [Accepted: 10/15/2018] [Indexed: 11/26/2022]
Abstract
The human brain can be conceptualized as an inference machine that actively predicts and explains its sensations and perceptions: it makes predictions through a probabilistic model. Such a model is continuously and implicitly updated by the computation and minimization of weighted prediction errors, as shown by numerous studies and experimental results. Nevertheless, such an algorithmic functioning of the brain has not been exploited in the neuropharmacological practice. In this manuscript, we show by theoretical analysis and model fitting of previously published data in two different contexts, how it is possible to increase the effectiveness of neuropharmacological and immunosuppressive drugs, through the modulation of the weighted prediction errors. Moreover, on the basis of the proposed model, we derive an optimized drug administration schedule able to increase the drug effectiveness of one order of magnitude, in psoriasis treatment. We make important testable predictions, evidencing the impact and the potential benefit of prediction errors modulation within the brain, in the pharmacotherapeutic practice. Finally, our results lead to a novel formal theory of implicit learning, and shed lights on the actual roles of classical conditioning and UCS revaluation in behavioral and pharmacological conditioning experiments. The potential practical implications of our results are many: the reduction of drugs side effects; the maximization of the therapeutic outcome; a more effective treatment for chronic pain, certain neuropsychiatric diseases, autoimmune diseases and allergic diseases.
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Affiliation(s)
- Luca Puviani
- University of Modena and Reggio Emilia, via Vivarelli 10, Modena, Italy.
| | - Sidita Rama
- Local Medical Unit, Via San Giovanni del Cantone, 23, Modena, Italy
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Are Adverse Events Induced by the Acute Administration of Calcineurin Inhibitor Cyclosporine A Behaviorally Conditioned in Healthy Male Volunteers? Clin Ther 2018; 40:1868-1877. [PMID: 30376962 DOI: 10.1016/j.clinthera.2018.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/14/2018] [Accepted: 09/15/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE The learned immunosuppressive placebo response has been demonstrated in experimental animals, healthy humans, and patients, and is suggested as a therapy for improving immunopharmacologic treatment. It remains unclear, however, whether potential adverse events induced by the drug are also behaviorally conditioned. Employing an established taste-immune learning paradigm in healthy humans using the calcineurin inhibitor and immunosuppressive drug cyclosporine A (CsA) as an unconditioned stimulus, we investigated whether and to what extent perceived adverse events induced by acute CsA administration are behaviorally conditioned. METHODS A total of 68 healthy male subjects were exposed to the established taste-immune learning paradigm, receiving either placebo or CsA (10 mg/kg) as an unconditioned stimulus, and a novel-tasting drink as a conditioned stimulus. FINDINGS Subjects repeatedly receiving CsA during acquisition reported significantly more adverse events than did placebo-receiving subjects. However, during reexposure to the conditioned stimulus, the reported adverse events did not differ from those in the placebo control condition. IMPLICATIONS These data indicate that acute adverse events are not behaviorally conditioned during the learned immunosuppressive response. Our results further strengthen the great potential clinical relevance of employing the learned immunosuppressive placebo response as a therapy to support immunopharmacologic regimens, ultimately aiming to reduce the medical dosages required, thereby minimizing adverse drug events while maximizing the therapeutic benefit in patients. German Clinical Trial Register (www.drks.de) identifier: DRKS00007693.
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Carlino E, Vase L. Can knowledge of Placebo and Nocebo Mechanisms Help Improve Randomized Clinical Trials? INTERNATIONAL REVIEW OF NEUROBIOLOGY 2018; 138:329-357. [PMID: 29681333 DOI: 10.1016/bs.irn.2018.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Over the last decade, there has been a substantial increase in negative results from randomized controlled trials (RCTs), which may be due to an increasing placebo response among other factors. Currently, identification and exclusion of placebo responders from trials are attempted to overcome this problem, but so far the success of these approaches has been limited. At the same time, the placebo-mechanism literature has highlighted how contextual factors, such as patients' expectations, interfere with the effect of drug administration, leading to a certain degree of uncertainty in RCTs. In this chapter, we review the current challenges of RCTs including the uncertainties of the active arm, the placebo arm, the additivity assumption, and the double-blind procedure. We use the placebo-mechanism literature to debate the strengths and weaknesses of attempts to identify and exclude placebo responders from trials. Finally, we illustrate how insights from the placebo-mechanism literature may point to new ways of improving RCTs.
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Affiliation(s)
| | - Lene Vase
- School of Business and Social Sciences, Aarhus University, Aarhus, Denmark.
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14
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Novel designs and paradigms to study the placebo response in gastroenterology. Curr Opin Pharmacol 2017; 37:72-79. [PMID: 29102743 DOI: 10.1016/j.coph.2017.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/04/2017] [Accepted: 10/06/2017] [Indexed: 12/18/2022]
Abstract
The investigation of the placebo and the nocebo effect and their mechanisms has a rather short history of less than 20 years, especially in gastroenterology, and only the last 5 years have resulted in substantial improvement of understanding. Placebo refers to symptom improvement following a treatment, nocebo to the opposite, symptom worsening. Among the factors driving this progress are traditional psychological models derived from learning (conditioning) theory bridging into clinical science, new animal models to investigate the pharmacology of placebo analgesia, and novel study designs to overcome limitations of traditional randomized and placebo-controlled study designs in drug testing. These are explored here for their implementation and application in gastroenterology, with a focus on visceral pain and nausea.
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