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Wu CY, Yu K, Arnold SE, Das S, Dodge HH. Who Benefited Most from the Internet-Based Conversational Engagement RCT (I-CONECT)? Application of the Personalized Medicine Approach to a Behavioral Intervention Study. J Prev Alzheimers Dis 2024; 11:639-648. [PMID: 38706280 PMCID: PMC11061034 DOI: 10.14283/jpad.2024.41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/09/2024] [Indexed: 05/07/2024]
Abstract
BACKGROUND Many Alzheimer's Disease (AD) clinical trials have failed to demonstrate treatment efficacy on cognition. It is conceivable that a complex disease like AD may not have the same treatment effect due to many heterogeneities of disease processes and individual traits. OBJECTIVES We employed an individual-level treatment response (ITR) approach to determine the characteristics of treatment responders and estimated time saved in cognitive decline using the Internet-based Conversational Engagement Clinical Trial (I-CONECT) behavioral intervention study as a model. DESIGN AND SETTING I-CONECT is a multi-site, single-blind, randomized controlled trial aimed to improve cognitive functions through frequent conversational interactions via internet/webcam. The experimental group engaged in video chats with study staff 4 times/week for 6 months; the control group received weekly 10-minute check-in phone calls. PARTICIPANTS Out of 186 randomized participants, current study used 139 participants with complete information on both baseline and 6-month follow-up (73 with mild cognitive impairment (MCI), 66 with normal cognition; 64 in the experimental group, and 75 in the control group). MEASUREMENTS ITR scores were generated for the Montreal Cognitive Assessment (MoCA) (global cognition, primary outcome) and Category Fluency Animals (CFA) (semantic fluency, secondary outcome) that showed significant efficacy in the trial. ITR scores were generated through 300 iterations of 3-fold cross-validated random forest models. The average treatment difference (ATD) curve and the area between the curves (ABC) were estimated to measure the heterogeneity of treatment responses. Responder traits were identified using SHapley Additive exPlanations (SHAP) and decision tree models. The time saved in cognitive decline was explored to gauge clinical meaningfulness. RESULTS ABC statistics showed substantial heterogeneity in treatment response with MoCA but modest heterogeneity in treatment response with CFA. Age, cognitive status, time spent with family and friends, education, and personality were important characteristics that influenced treatment responses. Intervention group participants in the upper 30% of ITR scores demonstrated potential delays of 3 months in semantic fluency (CFA) and 6 months in global cognition (MoCA), assuming a 5-fold faster natural cognitive decline compared to the control group during the post-treatment period. CONCLUSIONS ITR-based analyses are valuable in profiling treatment responders for features that can inform future trial design and clinical practice. Reliably measuring time saved in cognitive decline is an area of ongoing research to gain insight into the clinical meaningfulness of treatment.
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Affiliation(s)
- C-Y Wu
- Chao-Yi Wu, 149 13th floor, 10-003C, Boston, MA, USA, , 02129; 617-724-2428
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Basedow LA, Fischer A, Benson S, Bingel U, Brassen S, Büchel C, Engler H, Mueller EM, Schedlowski M, Rief W. The influence of psychological traits and prior experience on treatment expectations. Compr Psychiatry 2023; 127:152431. [PMID: 37862937 DOI: 10.1016/j.comppsych.2023.152431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/09/2023] [Accepted: 10/12/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Placebo and nocebo responses are modulated by the treatment expectations of participants and patients. However, interindividual differences predicting treatment expectations and placebo responses are unclear. In this large-scale pooled analysis, we aim to investigate the influence of psychological traits and prior experiences on treatment expectations. METHODS This paper analyses data from six different placebo studies (total n = 748). In all studies, participants' sociodemographic information, treatment expectations and prior treatment experiences and traits relating to stress, somatization, depression and anxiety, the Big Five and behavioral inhibition and approach tendencies were assessed using the same established questionnaires. Correlation coefficients and structural equation models were calculated to investigate the relationship between trait variables and expectations. RESULTS We found small positive correlations between side effect expectations and improvement expectations (r = 0.187), perceived stress (r = 0.154), somatization (r = 0.115), agitation (r = 0.108), anhedonia (r = 0.118), and dysthymia (r = 0.118). In the structural equation model previous experiences emerged as the strongest predictors of improvement (β = 0.32, p = .005), worsening (β = -0.24, p = .005) and side effect expectations (β = 0.47, p = .005). Traits related to positive affect (β = - 0.09; p = .007) and negative affect (β = 0.04; p = .014) were associated with side effect expectations. DISCUSSION This study is the first large analysis to investigate the relationship between traits, prior experiences and treatment expectations. Exploratory analyses indicate that experiences of symptom improvement are associated with improvement and worsening expectations, while previous negative experiences are only related to side effect expectations. Additionally, a proneness to experience negative affect may be a predictor for side effect expectation and thus mediate the occurrence of nocebo responses.
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Affiliation(s)
- Lukas A Basedow
- Philipps-Universität Marburg, Department of Clinical Psychology and Psychotherapy, 35037 Marburg, Germany.
| | - Anton Fischer
- Philipps-Universität Marburg, Department of Differential Psychology and Personality Research, 35037 Marburg, Germany.
| | - Sven Benson
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- and Behavioral Sciences, University Hospital of Essen, Essen, Germany.
| | - Ulrike Bingel
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, Essen, DE, Germany.
| | - Stefanie Brassen
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Christian Büchel
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Harald Engler
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- and Behavioral Sciences, University Hospital of Essen, Essen, Germany.
| | - Erik M Mueller
- Philipps-Universität Marburg, Department of Differential Psychology and Personality Research, 35037 Marburg, Germany.
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- and Behavioral Sciences, University Hospital of Essen, Essen, Germany; Osher Center for Integrative Health, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Winfried Rief
- Philipps-Universität Marburg, Department of Clinical Psychology and Psychotherapy, 35037 Marburg, Germany.
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Hartmann H, Banwinkler M, Riva F, Lamm C. To respond or not to respond: exploring empathy-related psychological and structural brain differences between placebo analgesia responders and non-responders. Front Psychol 2023; 14:1257522. [PMID: 37849473 PMCID: PMC10577216 DOI: 10.3389/fpsyg.2023.1257522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/14/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction Placebo responsiveness is highly variable across individuals. In the domain of pain, it may range from pronounced hypoalgesia to no response at all. Which factors predict such variation awaits clarification, as the available literature is characterized by mixed and inconclusive results. Particularly interesting in this case are social factors such as empathy or prosocial behavior, as prior work has stressed the connection between feeling pain yourself and empathizing with pain observed in others. Methods In a mixed confirmatory and exploratory approach, this study investigated potential psychological and structural brain differences between placebo responders and non-responders in the domain of pain. We aggregated data of four behavioral and neuroimaging studies that had been designed to investigate the effects of placebo analgesia on empathy. Results Analyses comparing groups of placebo responders and non-responders showed significant group differences in trait characteristics, with responders reporting increased helping behavior and lower psychopathic traits compared to non-responders. Uncorrected results further showed higher pain-related empathic concern in responders vs. non-responders. These results were accompaniedby tentative group differences in brain structure: placebo analgesia non-responders exhibited increased gray matter volume in left inferior temporal and parietal supramarginal cortical areas, and an increased cortical surface area in bilateral middle temporal cortex. Discussion Together, our findings suggest that modifiability of one's pain perception by means of placebo effects is linked to personality traits characterizing social emotions and behavior. They also hint that these psychological as well as brain structural characteristics might be beneficial for the identification of placebo responders. At the same time, they stress the importance of considering contextual factors such as the study setting or paradigm when investigating the association between individual characteristics and placebo responding.
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Affiliation(s)
- Helena Hartmann
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
- Clinical Neurosciences, Department of Neurology, University Hospital Essen, Essen, Germany
| | - Magdalena Banwinkler
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Federica Riva
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
| | - Claus Lamm
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
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Crawford LS, Meylakh N, Macey PM, Macefield VG, Keay KA, Henderson LA. Stimulus-independent and stimulus-dependent neural networks underpin placebo analgesia responsiveness in humans. Commun Biol 2023; 6:569. [PMID: 37244947 DOI: 10.1038/s42003-023-04951-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/18/2023] [Indexed: 05/29/2023] Open
Abstract
The neural circuits that regulate placebo analgesia responsivity are unknown, although engagement of brainstem pain modulatory regions is likely critical. Here we show in 47 participants that differences are present in neural circuit connectivity's in placebo responders versus non-responders. We distinguish stimulus-independent and stimulus-dependent neural networks that display altered connections between the hypothalamus, anterior cingulate cortex and midbrain periaqueductal gray matter. This dual regulatory system underpins an individual's ability to mount placebo analgesia.
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Affiliation(s)
- Lewis S Crawford
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Noemi Meylakh
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Paul M Macey
- UCLA School of Nursing, University of California, Los Angeles, CA, 90095, USA
| | - Vaughan G Macefield
- Department of Neuroscience, Monash University, Melbourne, VIC, 3800, Australia
| | - Kevin A Keay
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Luke A Henderson
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia.
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Horváth Á, Szabo A, Gál V, Suhaj C, Aranyosy B, Köteles F. Are there placebo or nocebo effects in balancing performance? Cogn Res Princ Implic 2023; 8:25. [PMID: 37093367 PMCID: PMC10126169 DOI: 10.1186/s41235-023-00476-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 04/05/2023] [Indexed: 04/25/2023] Open
Abstract
Placebo and nocebo effects could influence the perceived, actual, or both postural stabilities. Therefore, this experiment examined whether postural stability is susceptible to placebo and nocebo effects. Driven by expectations, these cognitions could influence the motor stability of people in physical rehabilitation and those with motion instability. We randomly assigned 78 participants to a placebo, nocebo, or control group. Then, we applied a sham sports cream with positive, negative, or neutral instructions about its impact on balance. Next, we tested postural stability with a modified version of the Modified Clinical Test of Sensory Interaction in Balance, including standard, proprioceptive, visual, and vestibular tests before and after the intervention. Further, we measured expected and perceived performance with visual analog scales and assessed trait anxiety, change in state anxiety, optimism, holistic thinking, persistence, and cooperation with questionnaires. The intervention did not affect actual test performances; similarly, trait and state variables and expectations did not have an impact. Furthermore, the experimental manipulation and trait and state variables did not significantly affect perceived performance. However, the association between expectation and perceived performance was strong (ϱ = 0.627, p < 0.001). These findings suggest that postural stability is not susceptible to placebo and nocebo influences. Still, there is a dissociation between objective and subjective performance, showing that expectations impact perceived but not actual performance, which could fuel motivation in rehabilitation settings.
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Affiliation(s)
- Áron Horváth
- Institute of Psychology, Károli Gáspár University of the Reformed Church in Hungary, Budapest, Hungary
- Institute of Psychology and Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, 1117, Budapest, Hungary
- Doctoral School of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Attila Szabo
- Institute of Psychology and Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, 1117, Budapest, Hungary.
- Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary.
| | - Vera Gál
- Institute of Psychology and Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, 1117, Budapest, Hungary
| | - Csilla Suhaj
- Institute of Psychology and Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, 1117, Budapest, Hungary
| | - Blanka Aranyosy
- Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ferenc Köteles
- Institute of Psychology, Károli Gáspár University of the Reformed Church in Hungary, Budapest, Hungary
- Institute of Psychology and Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, 1117, Budapest, Hungary
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Kang H, Miksche MS, Ellingsen DM. Association between personality traits and placebo effects: a preregistered systematic review and meta-analysis. Pain 2023; 164:494-508. [PMID: 35947877 DOI: 10.1097/j.pain.0000000000002753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 08/02/2022] [Indexed: 11/26/2022]
Abstract
ABSTRACT Placebo effects are ubiquitous yet highly variable between individuals and therefore strongly affect clinical trial outcomes such as pain relief. It is unclear whether dispositional psychological traits influence responsiveness to placebo. This preregistered meta-analysis and systematic review synthesized the literature investigating the association between personality traits and placebo effects. Based on 21 studies with 798 participants, we performed formal meta-analyses for 10 different personality traits, including behavioral inhibition, fun seeking, goal-drive persistence, reward responsiveness, empathic concern, empathic fantasy, perspective-taking, personal distress, optimism, and anxiety. We did not find evidence of associations between any of these traits and magnitude of placebo effects, which was supported by equivalence tests. Furthermore, we did not find evidence for moderating factors such as placebo manipulation type (conditioning or nonconditioning) or condition (pain or nonpain). These findings challenge the notion that personality influences responsiveness to placebos and contradict its utility for identifying placebo "responders" and "nonresponders."
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Affiliation(s)
- Heemin Kang
- Department of Psychology, University of Oslo, Norway
- Norwegian Centre for Mental Disorders Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | | | - Dan-Mikael Ellingsen
- Department of Psychology, University of Oslo, Norway
- Division of Radiology and Nuclear Medicine, Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway
- School of Health Sciences, Kristiania University College, Oslo, Norway
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Mathews AM, Riley I, Henderson R, Holbrook JT, Lang JE, Dixon AE, Wise RA, Que LG. Subgroup Analysis of a Randomized Trial of the Effects of Positive Messaging on Patient-Reported Outcomes with Asthma - Effect of Obesity. J Asthma Allergy 2022; 15:1743-1751. [PMID: 36506338 PMCID: PMC9733563 DOI: 10.2147/jaa.s336945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 08/14/2022] [Indexed: 12/12/2022] Open
Abstract
Objective Asthma in obese patients represents a specific phenotype that is associated with increased symptoms, more frequent and severe exacerbations, reduced responsiveness to treatment, and decreased quality of life. Marketing and placebos have been shown to alter subjective responses to interventions in both asthma and obesity. We evaluated obesity as a potential treatment effect modifier of the effects enhanced drug messaging or placebos on subjective asthma outcomes. Methods We conducted a secondary analysis of a multicenter, randomized clinical trial that studied the effect of messaging and placebos on asthma outcomes. A total of 601 participants were randomized (1:1:1:1:1) to one of 5 groups: enhanced messaging with montelukast or placebo, neutral messaging with montelukast or placebo, or usual care and followed for 4 weeks after randomization. We compared baseline characteristics by obesity status for 600 participants with data on body weight. Obesity was evaluated as an effect modifier for enhanced messaging (versus neutral messaging) and on placebo effects (versus usual care) in 362 participants assigned to a placebo group or usual care for three asthma questionnaires: Asthma Control Questionnaire, Asthma Quality of Life Questionnaire and Asthma Symptoms Utility Index. Results Overall, 227 (37%) of participants were obese. Obese participants were older (mean age 41 vs 34), more likely female (82% vs 67%) and self-identified as Black (44% vs 25%) than non-obese participants. As previously published, enhanced messaging was associated with improvements in patient-reported asthma scores, but there was no evidence for a placebo effect. Obesity status did not influence the message effects nor did it modify responses to placebo. Conclusion Obesity has been shown to be an important factor associated with asthma outcomes and an effect modifier of drug treatment effects. We conducted a post hoc, subgroup analysis of data from a multicenter randomized trial of enhanced messaging and placebo associated with drug treatment on asthma outcomes. Our findings suggest that observed differences in treatment effects between obese and non-obese patients sometimes seen in trials of asthma treatments are unlikely to be due to different "placebo" effects of treatment and may reflect differential physiologic effects of active agents.
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Affiliation(s)
- Anne M Mathews
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Duke University, Durham, NC, USA
| | - Isaretta Riley
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Duke University, Durham, NC, USA
| | - Robert Henderson
- Department of Epidemiology, Johns Hopkins Center for Clinical Trials and Evidence Synthesis, Baltimore, MD, USA
| | - Janet T Holbrook
- Department of Epidemiology, Johns Hopkins Center for Clinical Trials and Evidence Synthesis, Baltimore, MD, USA
| | - Jason E Lang
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Duke University, Durham, NC, USA
| | - Anne E Dixon
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, University of Vermont, Burlington, VT, USA
| | - Robert A Wise
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Loretta G Que
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Duke University, Durham, NC, USA
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Bodnár V, Bárdos G. Subjective and objective inebriation: a “Speed Dating” field study with placebo alcohol. JOURNAL OF SUBSTANCE USE 2022. [DOI: 10.1080/14659891.2022.2146013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Vivien Bodnár
- Doctoral School of Psychology, Institute of Psychology, Eötvös Loránd University, Budapest, Hungary
| | - György Bárdos
- Institute of Health Promotion and Sport Sciences, Faculty of Education and Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
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Boorman DC, Keay KA. Sex differences in morphine sensitivity are associated with differential glial expression in the brainstem of rats with neuropathic pain. J Neurosci Res 2022; 100:1890-1907. [PMID: 35853016 PMCID: PMC9543783 DOI: 10.1002/jnr.25103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 11/11/2022]
Abstract
Chronic pain is more prevalent and reported to be more severe in women. Opioid analgesics are less effective in women and result in stronger nauseant effects. The neurobiological mechanisms underlying these sex differences have yet to be clearly defined, though recent research has suggested neuronal–glial interactions are likely involved. We have previously shown that similar to people, morphine is less effective at reducing pain behaviors in female rats. In this study, we used the immunohistochemical detection of glial fibrillary acidic protein (GFAP) expression to investigate sex differences in astrocyte density and morphology in six medullary regions known to be modulated by pain and/or opioids. Morphine administration had small sex‐dependent effects on overall GFAP expression, but not on astrocyte morphology, in the rostral ventromedial medulla, the subnucleus reticularis dorsalis, and the area postrema. Significant sex differences in the density and morphology of GFAP immunopositive astrocytes were detected in all six regions. In general, GFAP‐positive cells in females showed smaller volumes and reduced complexity than those observed in males. Furthermore, females showed lower overall GFAP expression in all regions except for the area postrema, the critical medullary region responsible for opioid‐induced nausea and emesis. These data support the possibility that differences in astrocyte activity might underlie the sex differences seen in the processing of opioids in the context of chronic neuropathic pain.
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Affiliation(s)
- Damien C. Boorman
- School of Medical Sciences and the Brain and Mind Centre The University of Sydney Camperdown New South Wales Australia
| | - Kevin A. Keay
- School of Medical Sciences and the Brain and Mind Centre The University of Sydney Camperdown New South Wales Australia
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Wang Y, Chan E, Dorsey SG, Campbell CM, Colloca L. Who are the placebo responders? A cross-sectional cohort study for psychological determinants. Pain 2022; 163:1078-1090. [PMID: 34740998 PMCID: PMC8907332 DOI: 10.1097/j.pain.0000000000002478] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 09/02/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT A number of studies have demonstrated substantial individual differences in placebo effects. We aimed to identify individual psychological factors that potentially predicted the magnitude of placebo hypoalgesia and individual responsiveness. The Research Domain Criteria framework and a classical conditioning with suggestions paradigm were adopted as experimental models to study placebo phenotypes in a cohort of 397 chronic pain participants with a primary diagnosis of temporomandibular disorder (TMD) and 397 healthy control (HC) participants. The magnitude of placebo hypoalgesia was operationalized as the average difference in pain ratings between the placebo and control conditions. The individual placebo responsiveness was identified as the status of placebo responders and nonresponders based on a permutation test. We observed significant placebo effects in both TMD and HC participants. A greater level of emotional distress was a significant predictor of smaller magnitude (slope b = -0.07) and slower extinction rate (slope b = 0.51) of placebo effects in both TMD and HC participants. Greater reward seeking was linked to greater postconditioning expectations (ie, reinforced expectations) in TMD (slope b = 0.16), but there was no such a prediction in HC participants. These findings highlight that negative valence systems might play a role in impairing placebo effects, with a larger impact in chronic pain participants than in healthy participants, suggesting that individuals reporting emotional distress and maladaptive cognitive appraisals of pain may benefit less from placebo effects.
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Affiliation(s)
- Yang Wang
- Department of Pain and Translational Symptom Science,
School of Nursing, University of Maryland, Baltimore, MD, USA
- University of Maryland Center to Advance Chronic Pain
Research, Baltimore, MD, USA
| | - Esther Chan
- Department of Pain and Translational Symptom Science,
School of Nursing, University of Maryland, Baltimore, MD, USA
| | - Susan G. Dorsey
- Department of Pain and Translational Symptom Science,
School of Nursing, University of Maryland, Baltimore, MD, USA
- University of Maryland Center to Advance Chronic Pain
Research, Baltimore, MD, USA
- Departments of Anesthesiology and Medicine, School of
Medicine, University of Maryland, Baltimore, United States
| | - Claudia M. Campbell
- Department of Psychiatry and Behavioral Science, Johns
Hopkins University School of Medicine, Baltimore, MD, USA
| | - Luana Colloca
- Department of Pain and Translational Symptom Science,
School of Nursing, University of Maryland, Baltimore, MD, USA
- University of Maryland Center to Advance Chronic Pain
Research, Baltimore, MD, USA
- Departments of Anesthesiology and Psychiatry, School of
Medicine, University of Maryland, Baltimore, University of Maryland, Baltimore,
USA
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Vachon-Presseau E, Abdullah TB, Berger SE, Huang L, Griffith JW, Schnitzer TJ, Apkarian AV. Validating a biosignature-predicting placebo pill response in chronic pain in the settings of a randomized controlled trial. Pain 2022; 163:910-922. [PMID: 34433773 PMCID: PMC8863986 DOI: 10.1097/j.pain.0000000000002450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 08/08/2021] [Indexed: 11/25/2022]
Abstract
ABSTRACT The objective of this study is to validate a placebo pill response predictive model-a biosignature-that classifies chronic pain patients into placebo responders (predicted-PTxResp) and nonresponders (predicted-PTxNonR) and test whether it can dissociate placebo and active treatment responses. The model, based on psychological and brain functional connectivity, was derived in our previous study and blindly applied to current trial participants. Ninety-four chronic low back pain (CLBP) patients were classified into predicted-PTxResp or predicted-PTxNonR and randomized into no treatment, placebo treatment, or naproxen treatment. To monitor analgesia, back pain intensity was collected twice a day: 3 weeks baseline, 6 weeks of treatment, and 3 weeks of washout. Eighty-nine CLBP patients were included in the intent-to-treat analyses and 77 CLBP patients in the per-protocol analyses. Both analyses showed similar results. At the group level, the predictive model performed remarkably well, dissociating the separate effect sizes of pure placebo response and pure active treatment response and demonstrating that these effects interacted additively. Pain relief was about 15% stronger in the predicted-PTxResp compared with the predicted-PTxNonR receiving either placebo or naproxen, and the predicted-PTxNonR successfully isolated the active drug effect. At a single subject level, the biosignature better predicted placebo nonresponders, with poor accuracy. One component of the biosignature (dorsolateral prefrontal cortex-precentral gyrus functional connectivity) could be generalized across 3 placebo studies and in 2 different cohorts-CLBP and osteoarthritis pain patients. This study shows that a biosignature can predict placebo response at a group level in the setting of a randomized controlled trial.
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Affiliation(s)
- Etienne Vachon-Presseau
- Faculty of Dentistry, McGill University, Montreal, QC, Canada
- Department of Anesthesia, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Alan Edwards Centre for Research on Pain (AECRP), McGill University, Montreal, QC, Canada
| | - Taha B. Abdullah
- Department of Physiology, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
| | - Sara E. Berger
- Healthcare and Life Sciences Department, IBM Watson Research Center, 1101 Kitchawan Rd, Yorktown Heights, NY 10598, USA
| | - Lejian Huang
- Department of Physiology, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
| | - James W. Griffith
- Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
| | - Thomas J. Schnitzer
- Departments of Internal Medicine and Rheumatology, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
- Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
| | - A. Vania Apkarian
- Department of Physiology, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
- Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
- Department of Anesthesia, Northwestern University Feinberg School of Medicine, 710 N Lake Shore Drive, Room 1020, Chicago, IL 60611, USA
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Psycho-Neuro-Endocrine-Immunological Basis of the Placebo Effect: Potential Applications beyond Pain Therapy. Int J Mol Sci 2022; 23:ijms23084196. [PMID: 35457014 PMCID: PMC9028312 DOI: 10.3390/ijms23084196] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/03/2022] [Accepted: 04/04/2022] [Indexed: 12/12/2022] Open
Abstract
The placebo effect can be defined as the improvement of symptoms in a patient after the administration of an innocuous substance in a context that induces expectations regarding its effects. During recent years, it has been discovered that the placebo response not only has neurobiological functions on analgesia, but that it is also capable of generating effects on the immune and endocrine systems. The possible integration of changes in different systems of the organism could favor the well-being of the individuals and go hand in hand with conventional treatment for multiple diseases. In this sense, classic conditioning and setting expectations stand out as psychological mechanisms implicated in the placebo effect. Recent advances in neuroimaging studies suggest a relationship between the placebo response and the opioid, cannabinoid, and monoaminergic systems. Likewise, a possible immune response conditioned by the placebo effect has been reported. There is evidence of immune suppression conditioned through the insular cortex and the amygdala, with noradrenalin as the responsible neurotransmitter. Finally, a conditioned response in the secretion of different hormones has been determined in different studies; however, the molecular mechanisms involved are not entirely known. Beyond studies about its mechanism of action, the placebo effect has proved to be useful in the clinical setting with promising results in the management of neurological, psychiatric, and immunologic disorders. However, more research is needed to better characterize its potential use. This review integrates current knowledge about the psycho-neuro-endocrine-immune basis of the placebo effect and its possible clinical applications.
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13
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Schmidt K, Berding T, Kleine-Borgmann J, Engler H, Holle-Lee D, Gaul C, Bingel U. The beneficial effect of positive treatment expectations on pharmacological migraine prophylaxis. Pain 2022; 163:e319-e327. [PMID: 34010939 DOI: 10.1097/j.pain.0000000000002341] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/07/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Migraine is one of the leading causes of years lived with disability and considered to be a major global health concern. Pharmacological preventive treatment often causes side effects that limit the adherence to longer-term treatment regimens. Both experimental and clinical evidence suggests that positive expectations can modulate pain and analgesic treatment effects. However, the role of expectations in migraine prophylactic treatment has not systematically been investigated. Here, we examined the influence of treatment expectation before commencing pharmacological preventive treatment on its efficacy and tolerability in N = 134 episodic (30%) and chronic migraine (70%) patients in a prospective, longitudinal observational study over the course of 6 months. The migraine prophylaxis reduced the number of headache and migraine days with acceptable tolerability. Positive treatment expectation was associated with a generally lower number of headache and migraine days and a stronger reduction in headache days over the course of the treatment in chronic but not in episodic migraine patients. Moreover, patients with prior treatment showed a stronger reduction in headache days with higher expectation as compared to patients without prior experience. Our results underscore the relevance of further exploring the role of treatment expectation and its systematic modulation in patients with migraine and other pain conditions.
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Affiliation(s)
- Katharina Schmidt
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Tobias Berding
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Julian Kleine-Borgmann
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Harald Engler
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro-and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Dagny Holle-Lee
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Charly Gaul
- Migraine and Headache Clinic Königstein, Königstein, Germany
| | - Ulrike Bingel
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
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14
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Weng L, van Laarhoven AIM, Peerdeman KJ, Evers AWM. Do individual psychological characteristics predict induction and generalization of nocebo and placebo effects on pain and itch? Front Psychiatry 2022; 13:838578. [PMID: 35990075 PMCID: PMC9386339 DOI: 10.3389/fpsyt.2022.838578] [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: 12/18/2021] [Accepted: 07/05/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Nocebo and placebo effects, i.e., adverse or beneficial treatment effects, respectively, putatively due to expectancies can modulate pain and itch. These effects can generalize within the pain or itch modality. Predicting the induction and generalization of these effects can be helpful in clinical practice. This study aims to investigate whether psychological characteristics related to the fear-avoidance model predict the induction and generalization of nocebo and placebo effects on pain and itch in young healthy participants. METHODS Data from two previous experiments were analyzed. In Experiment 1, we induced nocebo and placebo effects on heat pain and tested generalization to pressure pain and to cowhage-evoked itch (n = 33 in a nocebo group, n = 32 in a placebo group). In Experiment 2, we induced nocebo effects on cowhage-evoked itch and tested generalization to mechanical itch and to mechanical touch (n = 44). Potential predictors were anxiety- and stress symptoms, attention to pain/itch, and pain/itch catastrophizing. Multiple regression analyses were performed. RESULTS For nocebo effects, none of the individual psychological characteristics significantly predicted induction of nocebo effects nor their generalization. For placebo effects, only less stress symptoms, lower attention to pain, and higher pain catastrophizing weakly predicted a stronger generalization of placebo effects from heat pain to pressure pain. CONCLUSION The tested psychological characteristics may not play an important role in the induction and generalization of nocebo and placebo effects in healthy individuals. However, firm conclusions cannot be drawn with the current sample. Future studies should validate findings in larger and more diverse samples.
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Affiliation(s)
- Lingling Weng
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands.,Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Antoinette I M van Laarhoven
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands.,Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Kaya J Peerdeman
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands.,Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Andrea W M Evers
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands.,Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands.,Department of Psychiatry, Leiden University Medical Center, Leiden, Netherlands.,Medical Delta, Leiden University, Technical University Delft, Rotterdam University, Rotterdam, Netherlands
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15
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Placebo and nocebo responses in randomised, controlled trials of medications for ADHD: a systematic review and meta-analysis. Mol Psychiatry 2022; 27:212-219. [PMID: 33972692 DOI: 10.1038/s41380-021-01134-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/26/2021] [Accepted: 04/14/2021] [Indexed: 11/09/2022]
Abstract
The nature and magnitude of placebo and nocebo responses to ADHD medications and the extent to which response to active medications and placebo are inter-correlated is unclear. To assess the magnitude of placebo and nocebo responses to ADHD and their association with active treatment response. We searched literature until June 26, 2019, for published/unpublished double-blind, randomised placebo-controlled trials (RCTs) of ADHD medication. Authors were contacted for additional data. We assessed placebo effects on efficacy and nocebo effects on tolerability using random effects meta-analysis. We assessed the association of study design and patient features with placebo/nocebo response. We analysed 128 RCTs (10,578 children/adolescents and 9175 adults) and found significant and heterogenous placebo effects for all efficacy outcomes, with no publication bias. The placebo effect was greatest for clinician compared with other raters. We found nocebo effects on tolerability outcomes. Efficacy outcomes from most raters showed significant positive correlations between the baseline to endpoint placebo effects and the baseline to endpoint drug effects. Placebo and nocebo effects did not differ among drugs. Baseline severity and type of rating scale influenced the findings. Shared non-specific factors influence response to both placebo and active medication. Although ADHD medications are superior to placebo, and placebo treatment in clinical practice is not feasible, clinicians should attempt to incorporate factors associated with placebo effects into clinical care. Future studies should explore how such effects influence response to medication treatment. Upon publication, data will be available in Mendeley Data: PROSPERO (CRD42019130292).
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16
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Seneviratne C, Noel J, Franklin PD, Colloca L. Editorial: Harnessing placebo mechanisms. Front Psychiatry 2022; 13:1022762. [PMID: 36172509 PMCID: PMC9512394 DOI: 10.3389/fpsyt.2022.1022762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 08/25/2022] [Indexed: 12/03/2022] Open
Affiliation(s)
- Chamindi Seneviratne
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, United States.,The Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jason Noel
- Department of Pharmacy Practice and Science, University of Maryland School of Pharmacy, Baltimore, MD, United States
| | - Patricia D Franklin
- Department of Partnerships, Professional Education and Practice, University of Maryland School of Nursing, Baltimore, MD, United States
| | - Luana Colloca
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD, United States.,The Placebo Beyond Opinion Center, University of Maryland School of Nursing, Baltimore, MD, United States
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17
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Parsons RD, Bergmann S, Wiech K, Terhune DB. Direct Verbal Suggestibility as a Predictor of Placebo Hypoalgesia Responsiveness. Psychosom Med 2021; 83:1041-1049. [PMID: 34297008 DOI: 10.1097/psy.0000000000000977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Reliably identifying good placebo responders has pronounced implications for basic research on, and clinical applications of, the placebo response. Multiple studies point to direct verbal suggestibility as a potentially valuable predictor of individual differences in placebo responsiveness, but previous research has produced conflicting results on this association. METHODS In two double-blind studies, we examined whether behavioral direct verbal suggestibility measures involving a correction for compliance would be associated with individual differences in responsiveness to conditioned and unconditioned placebo hypoalgesia using an established placebo analgesia paradigm. In study 1 (n = 57; mean [standard deviation] age = 23.7 [8.1] years; 77% women), we used behavioral hypnotic suggestibility as a predictor of placebo hypoalgesia induced through conditioning and verbal suggestion, whereas in study 2 (n = 78; mean [standard deviation] = 26.1 [7.4] years; 65% women), we measured nonhypnotic suggestibility and placebo hypoalgesia induced through verbal suggestion without conditioning. RESULTS In study 1, the placebo hypoalgesia procedure yielded a moderate placebo response (g = 0.63 [95% confidence interval = 0.32 to 0.97]), but the response magnitude did not significantly correlate with hypnotic suggestibility (rs = 0.11 [-0.17 to 0.37]). In study 2, the placebo procedure did not yield a significant placebo response across the full sample (g = 0.11 [-0.11 to 0.33]), but the magnitude of individual placebo responsiveness significantly correlated with nonhypnotic suggestibility (rs = 0.27 [0.03 to 0.48]). CONCLUSIONS These results suggest that the extent to which direct verbal suggestibility captures variability in placebo responsiveness depends on the use of conditioning and highlights the utility of suggestibility as a potential contributing factor to placebo responding when placebo hypoalgesia is induced through verbal suggestions.
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Affiliation(s)
- Ryan D Parsons
- From the Department of Psychology, Goldsmiths (Parsons, Bergmann, Terhune), University of London, London, United Kingdom; Department of Psychology (Parsons), University of Bath, Bath, England; and Wellcome Centre for Integrative Neuroimaging & Nuffield Department of Clinical Neurosciences (Wiech), University of Oxford, Oxford, United Kingdom
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18
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Cutoff criteria for the placebo response: a cluster and machine learning analysis of placebo analgesia. Sci Rep 2021; 11:19205. [PMID: 34584181 PMCID: PMC8479132 DOI: 10.1038/s41598-021-98874-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 09/16/2021] [Indexed: 11/08/2022] Open
Abstract
Computations of placebo effects are essential in randomized controlled trials (RCTs) for separating the specific effects of treatments from unspecific effects associated with the therapeutic intervention. Thus, the identification of placebo responders is important for testing the efficacy of treatments and drugs. The present study uses data from an experimental study on placebo analgesia to suggest a statistical procedure to separate placebo responders from nonresponders and suggests cutoff values for when responses to placebo treatment are large enough to be separated from reported symptom changes in a no-treatment condition. Unsupervised cluster analysis was used to classify responders and nonresponders, and logistic regression implemented in machine learning was used to obtain cutoff values for placebo analgesic responses. The results showed that placebo responders can be statistically separated from nonresponders by cluster analysis and machine learning classification, and this procedure is potentially useful in other fields for the identification of responders to a treatment.
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19
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Muthukumaraswamy SD, Forsyth A, Lumley T. Blinding and expectancy confounds in psychedelic randomized controlled trials. Expert Rev Clin Pharmacol 2021; 14:1133-1152. [PMID: 34038314 DOI: 10.1080/17512433.2021.1933434] [Citation(s) in RCA: 115] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: There is increasing interest in the potential for psychedelic drugs such as psilocybin, LSD and ketamine to treat several mental health disorders, with a growing number of randomized controlled trials (RCTs) being conducted to investigate the therapeutic effectiveness of psychedelics.Areas covered: We review previous literature on expectancy effects and blinding in the context of psychedelic RCTs - literature which strongly suggest that psychedelic RCTs might be confounded by de-blinding and expectancy. We conduct systematic reviews of psychedelic RCTs using Medline, PsychInfo and EMBASE (Jan 1990 - Nov 2020) and show that currently reported psychedelic RCTs have generally not reported pre-trial expectancy, nor the success of blinding procedures.Expert opinion: While psychedelic RCTs have generally shown promising results, with large effect sizes reported, we argue that treatment effect sizes in psychedelic RCTs are likely over-estimated due to de-blinding of participants and high levels of response expectancy. We suggest that psychedelic RCTs should routinely measure de-blinding and expectancy. Careful attention should be paid to clinical trial design and the instructions given to participants to allow these confounds to be reduced, estimated and removed from effect size estimates. We urge caution in interpreting effect size estimates from extant psychedelic RCTs.
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Affiliation(s)
| | - Anna Forsyth
- School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Thomas Lumley
- Department of Statistics, The University of Auckland, Auckland, New Zealand
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20
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Schmidt K, Kleine-Borgmann J, Holle-Lee D, Gaul C, Bingel U. Impact of a 12-week open-label placebo treatment on headache days in episodic and chronic migraine: a study protocol for a parallel-group, multicentre, randomised controlled trial. BMJ Open 2021; 11:e045969. [PMID: 34162645 PMCID: PMC8230930 DOI: 10.1136/bmjopen-2020-045969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Migraine is the most common neurological disorder and one of the major causes of years lived with disability. Its treatment (especially of chronic forms) is often challenging and accompanied with adverse effects. Although new therapeutic approaches have recently emerged (eg, calcitonin gene-related peptide antibodies), these are linked to strict prescribing guidelines and therefore limited to only a minority of patients. Recently, randomised controlled trials have demonstrated that open-label placebo treatments can lead to significant and clinically relevant improvements of chronic pain conditions. METHODS AND ANALYSIS This multicentre, randomised controlled clinical trial following a parallel group between-subject design aims to systematically investigate the impact of a 12-week open-label placebo treatment on moderate to severe headache days (primary outcome) in patients with episodic and chronic migraine in addition to treatment as usual. Secondary outcomes comprise the number of migraine days, pain intensity, intake of acute medication, quality of life, disability, global impression of change, tolerability and a responder rate. To systematically address potential predictors of placebo responses in patients with migraine, this study assesses potential psychometric predictors, salivary cortisol and alpha-amylase awakening responses, catechol-o-methyltransferase Val158Met polymorphisms, as well as functional and structural brain connectivity (ie, resting state functional MRI, diffusion tensor imaging). The data analysis will be performed on basis of the general linear model considering repeated measures (mixed model). ETHICS AND DISSEMINATION This protocol and all corresponding documents were approved with regard to their content and compliance with ethical regulations by the Ethics Committee of the Medical Faculty of the University Duisburg-Essen, Germany and the Ethics Committee of the Landesärztekammer Hessen. The results from this study will be actively disseminated through manuscript publications and conference presentations. TRIAL REGISTRATION NUMBER German Clinical Trials Register (DRKS00021259).
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Affiliation(s)
- Katharina Schmidt
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences, University Medicine Essen, Essen, Germany
| | - Julian Kleine-Borgmann
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences, University Medicine Essen, Essen, Germany
| | - Dagny Holle-Lee
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences, University Medicine Essen, Essen, Germany
| | - Charly Gaul
- Migraine and Headache Clinic Koenigstein, Königstein im Taunus, Germany
| | - Ulrike Bingel
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences, University Medicine Essen, Essen, Germany
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21
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Flowers KM, Patton ME, Hruschak VJ, Fields KG, Schwartz E, Zeballos J, Kang JD, Edwards RR, Kaptchuk TJ, Schreiber KL. Conditioned open-label placebo for opioid reduction after spine surgery: a randomized controlled trial. Pain 2021; 162:1828-1839. [PMID: 33449503 PMCID: PMC8378225 DOI: 10.1097/j.pain.0000000000002185] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/31/2020] [Indexed: 12/19/2022]
Abstract
ABSTRACT Placebo effects have traditionally involved concealment or deception. However, recent evidence suggests that placebo effects can also be elicited when prescribed transparently as "open-label placebos" (OLPs), and that the pairing of an unconditioned stimulus (eg, opioid analgesic) with a conditioned stimulus (eg, placebo pill) can lead to the conditioned stimulus alone reducing pain. In this randomized control trial, we investigated whether combining conditioning with an OLP (COLP) in the immediate postoperative period could reduce daily opioid use and postsurgical pain among patients recovering from spine surgery. Patients were randomized to COLP or treatment as usual, with both groups receiving unrestricted access to a typical opioid-based postoperative analgesic regimen. The generalized estimating equations method was used to assess the treatment effect of COLP on daily opioid consumption and pain during postoperative period from postoperative day (POD) 1 to POD 17. Patients in the COLP group consumed approximately 30% less daily morphine milligram equivalents compared with patients in the treatment as usual group during POD 1 to 17 (-14.5 daily morphine milligram equivalents; 95% CI: [-26.8, -2.2]). Daily worst pain scores were also lower in the COLP group (-1.0 point on the 10-point scale; 95% CI: [-2.0, -0.1]), although a significant difference was not detected in average daily pain between the groups (-0.8 point; 95% CI: [-1.7, 0.2]). These findings suggest that COLP may serve as a potential adjuvant analgesic therapy to decrease opioid consumption in the early postoperative period, without increasing pain.
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Affiliation(s)
- Kelsey M. Flowers
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Megan E. Patton
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Valerie J. Hruschak
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Kara G. Fields
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Emily Schwartz
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Jose Zeballos
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - James D. Kang
- Departments of Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Rob R. Edwards
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Ted J. Kaptchuk
- Program in Placebo Studies and Therapeutic Encounter, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Kristin L. Schreiber
- Departments of Anesthesiology, Perioperative, and Pain Medicine Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
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22
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Sondermann W, Reinboldt-Jockenhöfer F, Dissemond J, Pfaar O, Bingel U, Schedlowski M. Effects of Patients' Expectation in Dermatology: Evidence from Experimental and Clinical Placebo Studies and Implications for Dermatologic Practice and Research. Dermatology 2021; 237:857-871. [PMID: 33498052 DOI: 10.1159/000513445] [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: 10/02/2020] [Accepted: 11/28/2020] [Indexed: 11/19/2022] Open
Abstract
Patients' expectations towards the benefit of a treatment are key determinants of placebo responses and can affect the development and course of medical conditions and the efficacy and tolerability of active medical treatment. The mechanisms mediating these placebo and nocebo effects have been best described in the field of experimental pain and placebo analgesia. However, also in dermatology experimental and clinical studies demonstrate that various skin diseases such as inflammatory dermatoses and allergic reactions can be modulated by patients' expectations. Dermatologists should consider the important modulatory role of patients' expectations on the efficacy and tolerability of specific treatments and the key role of verbal information, patients' prior treatment experiences (associative learning), and the quality and quantity of doctor-patient communication in shaping treatment expectation. As a consequence, techniques aiming at maximizing patients' expectation effects should be implemented into daily clinical routine. By contrast, in clinical studies expectation effects should be maximally controlled and harmonized to improve the "assay sensitivity" to detect new compounds. Further translational studies, also in dermatoses that have not been investigated yet, are needed to better characterize the mechanisms underlying patients' expectation and to gain further insights into potential clinical implications of these effects in dermatologic conditions. Therefore, in this review, we provide a brief overview on the concept of expectation effects on treatment outcome in general, summarize what is already known about this topic for dermatologic diseases, and finally present the relevance of this topic in clinical dermatology.
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Affiliation(s)
- Wiebke Sondermann
- Department of Dermatology, Venereology, and Allergology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany,
| | - Finja Reinboldt-Jockenhöfer
- Department of Dermatology, Venereology, and Allergology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Joachim Dissemond
- Department of Dermatology, Venereology, and Allergology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Oliver Pfaar
- Section of Rhinology and Allergy, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Marburg, Philipps University Marburg, Marburg, Germany
| | - Ulrike Bingel
- Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.,Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
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23
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Morphine-Conditioned Placebo Analgesia in Female and Male Rats with Chronic Neuropathic Pain: c-Fos Expression in the Rostral Ventromedial Medulla. Neuroscience 2020; 457:51-73. [PMID: 33285237 DOI: 10.1016/j.neuroscience.2020.11.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/19/2020] [Accepted: 11/23/2020] [Indexed: 12/17/2022]
Abstract
Placebo analgesia has great potential to overcome the inadequacies of current drug therapies to treat conditions of chronic pain. The rostral ventromedial medulla (RVM) has been implicated as a critical relay in the antinociceptive pathway underpinning placebo analgesia in humans. We developed a model of opiate-conditioned placebo analgesia in rats with neuropathic injury to identify medullary nuclei active during placebo analgesia. Using female and male rats the degree of thermal allodynia was first determined following nerve injury, and a pharmacological conditioning procedure, pairing contextual cues with the experience of morphine-induced analgesia, was used to elicit placebo analgesic reactions. This protocol revealed clear subpopulations of placebo reactors (36% of males, 25% of females) and non-reactors in proportions similar to those reported in human studies. We detected injury-specific c-Fos expression in the gracile nucleus and morphine-specific c-Fos expression in the serotonergic midline raphe nuclei and the caudal nuclei of the solitary tract. However, c-Fos expression did not differ between placebo reactors and non-reactors in either serotonergic or non-serotonergic neurons of the RVM. Despite a subpopulation of rats demonstrating placebo reactions, we found no evidence for enhanced activity in the nuclei from which the classical RVM → spinal cord descending analgesic pathways emerge.
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24
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Bräscher AK, Schulz SM, Van den Bergh O, Witthöft M. Prospective study of nocebo effects related to symptoms of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF). ENVIRONMENTAL RESEARCH 2020; 190:110019. [PMID: 32777274 DOI: 10.1016/j.envres.2020.110019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/27/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
The exact causes of Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields (IEI-EMF, i.e., experience of somatic symptoms attributed to low-level electromagnetic fields) are still unknown. Psychological causation such as nocebo effects seem plausible. This study aimed to experimentally induce a nocebo effect for somatic symptom perception and examined whether it was reproducible after one week. We also examined whether these effects were associated with increased sympathetic activity and whether interoceptive accuracy (IAcc) moderated these relationships. Participants were recruited from the general population and instructed that electromagnetic exposure can enhance somatosensory perception. They participated twice in a cued exposure experiment with tactile stimulation and sham WiFi exposure in 50% of trials. The two sessions were scheduled one week apart (session 1: N = 65, session 2: N = 63). Before session 1, participants watched either a 6-min film on adverse health effects of EMF or a neutral film on trade of mobile phones. IAcc was assessed with the heartbeat detection paradigm. Electrodermal activity served as a measure of sympathetic activation. Evidence for a nocebo effect (i.e., increased self-reported intensity and aversiveness and electrodermal activity) during sham WiFi exposure was observed in both sessions. IAcc moderated the nocebo effect, depending on stimulus intensity. Contrary to previous findings, no difference emerged between the health-related EMF and the neutral films. Based on negative instructions, somatic perception and physiological responding can be altered. This is consistent with the assumption that IEI-EMF could be due to nocebo effects, suggesting an important role for psychological interventions.
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Affiliation(s)
- Anne-Kathrin Bräscher
- Johannes Gutenberg University Mainz, Department for Clinical Psychology, Psychotherapy, and Experimental Psychopathology, Germany.
| | - Stefan M Schulz
- Johannes Gutenberg University Mainz, Department for Clinical Psychology, Psychotherapy, and Experimental Psychopathology, Germany
| | | | - Michael Witthöft
- Johannes Gutenberg University Mainz, Department for Clinical Psychology, Psychotherapy, and Experimental Psychopathology, Germany
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Vase L. Can insights from placebo and nocebo mechanisms studies improve the randomized controlled trial? Scand J Pain 2020; 20:451-467. [PMID: 32609651 DOI: 10.1515/sjpain-2019-0183] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Indexed: 11/15/2022]
Abstract
Background and aims The randomized controlled trial (RCT) is currently facing several challenges, one of these being that the placebo response appears to be increasing in RCTs, thereby making it difficult to demonstrate an effect of potentially new treatments over placebo. This problem has primarily been approached by predicting the magnitude of the placebo response via stable factors, such as demographic variables, and/or by developing complex designs aimed at reducing the placebo response in the hope that it will improve the test of the active treatment. Yet, the success of this approach has so far been limited. Methods A new approach toward improving the RCT is put forward based on placebo and nocebo mechanism studies, i.e. studies that investigate the mechanisms underlying placebo analgesia and nocebo hyperalgesia. In a series of meta-analyses the magnitude of placebo and nocebo effects were determined. Experimental studies across nociplastic and neuropathic pain conditions and across pharmacological and acupuncture treatments investigated psychological and neurobiological mechanisms underlying these effects. The obtained results were used to make approximations of expectations to see if that could predict the placebo response in RCTs and function as a new way of tapping into the placebo component of treatment effects. Results The magnitude of placebo and nocebo effects is large and highly variable. Placebo effects exist across chronic pain conditions with varying degrees of known etiology as well as across pharmacological and non-pharmacological treatments. Patients' perception of the treatment, the verbal suggestions given for pain relief, and the patients' expectations toward pain relief contribute to the magnitude of the placebo effect and to pain relief following placebo interventions. Also, unintentional unblinding and patients' perception of a treatment markedly influence the treatment outcome. By making approximations of expectations toward treatment effects it was possible to predict the magnitude of the placebo response in RCTs. Conclusions and implications The new approach of tapping into or directly asking patients about their perception and expectations toward a treatment, along with the account of the natural history of pain, has the potential to improve the information that can be obtained from RCTs. Thus, by interfacing insights from placebo and nocebo mechanism studies, it may be possible to enhance the information that can be obtained from RCTs and to account for a large part of the variability in the placebo component of the overall treatment effect. This approach has the potential to improve the scientific evaluation of treatments, as well as to illustrate how the effect of treatments can be optimized in clinical practice, which is the crux of evidence-based medicine.
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Affiliation(s)
- Lene Vase
- Department of Psychology and Behavioural Sciences, Aarhus University, Bartholins Allé 11, Building 1350, DK-8000 Aarhus C, Denmark
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Lindheimer JB, Szabo A, Raglin JS, Beedie C. Advancing the understanding of placebo effects in psychological outcomes of exercise: Lessons learned and future directions. Eur J Sport Sci 2020; 20:326-337. [PMID: 31215360 PMCID: PMC6949426 DOI: 10.1080/17461391.2019.1632937] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Despite the apparent strength of scientific evidence suggesting that psychological benefits result from both acute and chronic exercise, concerns remain regarding the extent to which these benefits are explained by placebo effects. Addressing these concerns is methodologically and at times conceptually challenging. However, developments in the conceptualisation and study of placebo effects from the fields of psychology, neuroscience, pharmacology, and human performance offer guidance for advancing the understanding of placebo effects in psychological responses to exercise. In clinical trials, expectations can be measured and experimentally manipulated to better understand the influence of placebo effects on treatment responses. Further, compelling evidence has shown that the contribution of placebo effects and their underlying neurobiological mechanisms to treatment effects can be measured without administering a traditional placebo (e.g. inert substance) by leveraging psychological factors such as expectations and conditioning. Hence, the purpose of this focused review is to integrate lessons such as these with the current body of literature on placebo effects in psychological responses to exercise and provide recommendations for future research directions.
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Affiliation(s)
- Jacob B Lindheimer
- Department of Veterans Affairs, William S. Middleton Veterans Memorial Hospital, Madison, WI, USA
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Attila Szabo
- Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, Budapest Hungary
| | - John S Raglin
- Department of Kinesiology, Indiana University, Bloomington, IN, USA
| | - Chris Beedie
- School of Psychology, University of Kent, Canterbury, UK
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Abstract
Nocebo effects occur when an individual experiences undesirable physiological reactions caused by doxastic states that are not a treatment's core or characteristic features.1 As Scott Gelfand2 points out, there are numerous studies that have shown that the disclosure of a treatment's side effects to a patient increases the risk of the side effects. From an ethical point of view, nocebo effects caused by the disclosures of side effects present a challenging problem. On the one hand, clinicians' duty to inform patients of the consequences (including possible side effects) of their treatments is critical in ensuring that patients' autonomy is respected. Patients cannot act autonomously if relevant information is withheld from them (without their consent, perhaps). On the other hand, clinicians also ought to minimize harm to patients.
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Kern A, Kramm C, Witt CM, Barth J. The influence of personality traits on the placebo/nocebo response: A systematic review. J Psychosom Res 2020; 128:109866. [PMID: 31760341 DOI: 10.1016/j.jpsychores.2019.109866] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Some people might be more prone to placebo and nocebo responses than others depending on their personality traits. We aimed to provide a systematic review on the influence of personality traits on placebo and nocebo responses in controlled and uncontrolled studies. METHODS We conducted a systematic literature search in the databases CINAHL, AMED, PsycINFO and EMBASE for relevant publications published between January 1997 and March 2018. For all included papers, we conducted an additional forward search. RESULTS After screening 407 references, we identified 24 studies. The Big Five (i.e., neuroticism, extraversion, openness to experience, agreeableness and conscientiousness) and optimism were the most frequently investigated personality traits. Several studies found a positive association between optimism and the placebo response. Furthermore, we found that higher anxiety was associated with increased nocebo responses. CONCLUSION Evidence points to a possible association between optimism and the placebo response. Therefore, further emphasising the investigation of the influence of optimism on the placebo/nocebo response seems warranted. For clinical practice, the impact of anxiety on the nocebo response might be important to identify patients who might be more prone to experiencing side effects of medical treatments.
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Affiliation(s)
- Alexandra Kern
- Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland.
| | - Christoph Kramm
- Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Claudia M Witt
- Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland; Institute for Social Medicine, Epidemiology and Health Economics, Charité Universitätsmedizin Berlin, Berlin, Germany; Center for Integrative Medicine, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Jürgen Barth
- Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
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Egorova N, Benedetti F, Gollub RL, Kong J. Between placebo and nocebo: Response to control treatment is mediated by amygdala activity and connectivity. Eur J Pain 2019; 24:580-592. [PMID: 31770471 DOI: 10.1002/ejp.1510] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 09/08/2019] [Accepted: 11/19/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND In experimental placebo and nocebo studies, neutral control treatments are often administered for comparison with active treatments, but are of little interest, as, on average, they result in little change. Yet, when considered at an individual level, they fluctuate between baseline and subsequent measurements and may reveal important information about participants' placebo/nocebo responding tendencies. METHODS In a paradigm involving application of creams paired with positive, negative and neutral expectations, some subjects rated identical stimuli in the neutral condition as more painful while others as less painful after treatment with inert cream. We divided subjects into two groups based on the median split in these pre-post responses in the neutral control condition, and investigated (a) fMRI signal differences (post minus pre) between the two groups in neutral condition, and (b) seed-based resting state connectivity of the bilateral amygdala, known to be involved in emotional self-regulation, as well as ambiguous stimulus processing and aversive learning. RESULTS The results suggested that subjects who rated the same pain stimuli after treatment with explicitly neutral cream as more painful showed stronger fMRI activation of the amygdala during the experiment and had higher connectivity between the left amygdala and the striatum at rest. Neutral pre-post changes predicted behavioural placebo/nocebo response in this and two independent datasets. CONCLUSION These findings suggest that measuring pre-post change in the neutral control condition might provide important information about subjects' individual differences in placebo/nocebo response. SIGNIFICANCE Pre-post changes in pain ratings in neutral conditions are modulated by amygdala activity and connectivity and can be used to predict placebo/nocebo responses.
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Affiliation(s)
- Natalia Egorova
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, USA.,The Florey Institute of Neuroscience and Mental Health, Melbourne, Vic., Australia.,Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, Vic., Australia
| | - Fabrizio Benedetti
- University of Turin, Turin, Italy.,Plateau Rosà Labs, Plateau Rosà, Switzerland
| | - Randy L Gollub
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, USA
| | - Jian Kong
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, USA
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Vase L, Wartolowska K. Pain, placebo, and test of treatment efficacy: a narrative review. Br J Anaesth 2019; 123:e254-e262. [PMID: 30915982 PMCID: PMC6676016 DOI: 10.1016/j.bja.2019.01.040] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/22/2019] [Accepted: 01/28/2019] [Indexed: 01/09/2023] Open
Abstract
Over the past decade, the mechanisms underlying placebo effects have begun to be identified. At the same time, the placebo response appears to have increased in pharmacological trials and marked placebo effects are found in neurostimulation and surgical trials, thereby posing the question whether non-pharmacological interventions should be placebo-controlled to a greater extent. In this narrative review we discuss how the knowledge of placebo mechanisms may help to improve placebo control in pharmacological and non-pharmacological trials. We review the psychological, neurobiological, and genetic mechanisms underlying placebo analgesia and outline the current problems and potential solutions to the challenges with placebo control in trials on pharmacological, neurostimulation, and surgical interventions. We particularly focus on how patients' perception of the therapeutic intervention, and their expectations towards treatment efficacy may help develop more precise placebo controls and blinding procedures and account for the contribution of placebo factors to the efficacy of active treatments. Finally, we discuss how systematic investigations into placebo mechanisms across various pain conditions and types of treatment are needed in order to 'personalise' the placebo control to the specific pathophysiology and interventions, which may ultimately lead to identification of more effective treatment for pain patients. In conclusion this review shows that it is important to understand how patients' perception and expectations influence the efficacy of active and placebo treatments in order to improve the test of new treatments. Importantly, this applies not only to assessment of drug efficacy but also to non-pharmacological trials on surgeries and stimulation procedures.
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Affiliation(s)
- Lene Vase
- Department of Psychology and Behavioural Sciences, School of Business and Social Sciences, Aarhus University, Aarhus, Denmark.
| | - Karolina Wartolowska
- Nuffield Department of Primary Care Health Services, University of Oxford, Oxford, UK.
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Wolters F, Peerdeman KJ, Evers AW. Placebo and Nocebo Effects Across Symptoms: From Pain to Fatigue, Dyspnea, Nausea, and Itch. Front Psychiatry 2019; 10:470. [PMID: 31312148 PMCID: PMC6614509 DOI: 10.3389/fpsyt.2019.00470] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/13/2019] [Indexed: 01/06/2023] Open
Abstract
Placebo and nocebo effects are, respectively, the helpful and harmful treatment effects that do not arise from active treatment components. These effects have thus far been researched most often in pain. It is not yet clear to what extent these findings from pain can be generalized to other somatic symptoms. This review investigates placebo and nocebo effects in four other highly prevalent symptoms: dyspnea, fatigue, nausea, and itch. The role of learning mechanisms (verbal suggestions, conditioning) in placebo and nocebo effects on various outcomes (self-reported, behavioral, and physiological) of these different somatic symptoms is explored. A search of experimental studies indicated that, as in pain, the combination of verbal suggestion and conditioning is generally more effective than suggestion alone for evoking placebo and nocebo effects. However, conditioning appears more and verbal suggestions less relevant in symptoms other than pain, with the exception of placebo effects on fatigue and nocebo effects on itch. Physiological measures, such as heart rate, lung function, or gastric activity, are rarely affected even when self-reported symptoms are. Neurobiological correlates are rarely investigated, and few commonalities appear across symptoms. Expectations generally predict placebo and nocebo effects for dyspnea and itch but seem less involved in fatigue and nausea. Individual characteristics do not consistently predict placebo or nocebo effects across symptoms or studies. In sum, many conclusions deriving from placebo and nocebo pain studies do appear to apply to other somatic symptoms, but a number of important differences exist. Understanding what type of learning mechanisms for which symptom are most likely to trigger placebo and nocebo effects is crucial for generalizing knowledge for research and therapies across symptoms and can help clinicians to optimize placebo effects in practice.
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Affiliation(s)
- Fabian Wolters
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Kaya J. Peerdeman
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Andrea W.M. Evers
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
- Department of Psychiatry, Leiden University Medical Center, Leiden, Netherlands
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Magnitude, response, and psychological determinants of placebo effects in chronic low-back pain: a randomised, double-blinded, controlled trial. Pain Rep 2019; 4:e744. [PMID: 31583358 PMCID: PMC6749916 DOI: 10.1097/pr9.0000000000000744] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 02/17/2019] [Accepted: 03/12/2019] [Indexed: 11/26/2022] Open
Abstract
Introduction: Denervation of the lumbar zygapophyseal joints by medial branch radiofrequency neurotomy has shown some benefit in treating chronic low-back pain. Before denervation, a diagnosis is made by one or more blinded injections on separate occasions to ascertain whether the relevant joints are contributing to the pain. Placebo injections have been advocated in a diagnostic regime that also includes local anaesthesia, with a decision to proceed to neurotomy based on response to local anaesthesia and not to placebo. Objectives: We investigated the magnitude of and response rate to placebo injections, and the roles of expectation, desire for pain relief, and anxiety as determinants of response to placebo. Methods: One hundred twenty patients were randomised to receive placebo and local anaesthetic injections on alternate occasions in a double-blind manner. A smaller control group with 2 local anaesthetic injections was also used. Responses to placebo were characterised, including magnitude and frequency. Results: This study demonstrated very large response to placebo injections, both response rate (78%) and magnitude (effect size d = 1.85). Expectation and anxiety were important modulators of response to placebo in this setting, with support given to expectation as a dynamic modulator of placebo responses. Large response to placebo (both in rate and magnitude) was observed when participants reported the belief that they were in the placebo arm. Conclusion: This study demonstrated large placebo responses in the context of injections for low-back pain and further characterised the importance of expectation and anxiety as important psychological mediators.
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Shinohara K, Tanaka S, Imai H, Noma H, Maruo K, Cipriani A, Yamawaki S, Furukawa TA. Development and validation of a prediction model for the probability of responding to placebo in antidepressant trials: a pooled analysis of individual patient data. EVIDENCE-BASED MENTAL HEALTH 2019; 22:10-16. [PMID: 30665989 PMCID: PMC10270413 DOI: 10.1136/ebmental-2018-300073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 12/12/2018] [Accepted: 12/21/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Identifying potential placebo responders among apparent drug responders is critical to dissect drug-specific and nonspecific effects in depression. OBJECTIVE This project aimed to develop and test a prediction model for the probability of responding to placebo in antidepressant trials. Such a model will allow us to estimate the probability of placebo response among drug responders in antidepressants trials. METHODS We identified all placebo-controlled, double-blind randomised controlled trials (RCTs) of second generation antidepressants for major depressive disorder conducted in Japan and requested their individual patient data (IPD) to pharmaceutical companies. We obtained IPD (n=1493) from four phase II/III RCTs comparing mirtazapine, escitalopram, duloxetine, paroxetine and placebo. Out of 1493 participants in the four clinical trials, 440 participants allocated to placebo were included in the analyses. Our primary outcome was response, defined as 50% or greater reduction on Hamilton Rating Scale for Depression at study endpoint. We used multivariable logistic regression to develop a prediction model. All available candidate of predictor variables were tested through a backward variable selection and covariates were selected for the prediction model. The performance of the model was assessed by using Hosmer-Lemeshow test for calibration and the area under the ROC curve for discrimination. FINDINGS Placebo response rates differed between 31% and 59% (grand average: 43%) among four trials. Four variables were selected from all candidate variables and included in the final model: age at onset, age at baseline, bodily symptoms, and study-level difference. The final model performed satisfactorily in terms of calibration (Hosmer-Lemeshow p=0.92) and discrimination (the area under the ROC curve (AUC): 0.70). CONCLUSIONS Our model is expected to help researchers discriminate individuals who are more likely to respond to placebo from those who are less likely so. CLINICAL IMPLICATIONS A larger sample and more precise individual participant information should be collected for better performance. Examination of external validity in independent datasets is warranted. TRIAL REGISTRATION NUMBER CRD42017055912.
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Affiliation(s)
- Kiyomi Shinohara
- Department of Health Promotion and Human Behavior and of Clinical Epidemiology, Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan
| | - Shiro Tanaka
- Department of Clinical Biostatistics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hissei Imai
- Department of Health Promotion and Human Behavior and of Clinical Epidemiology, Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan
| | - Hisashi Noma
- Department of Data Science, The Institute of Statistical Mathematics, Tokyo, Japan
| | - Kazushi Maruo
- Department of Biostatistics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Andrea Cipriani
- Department of Psychiatry, University of Oxford, Oxford, UK
- Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Shigeto Yamawaki
- Academic-Industrial Cooperation Office, Hiroshima University, Hiroshima, Japan
| | - Toshi A Furukawa
- Department of Health Promotion and Human Behavior and of Clinical Epidemiology, Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan
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Sagy I, Abres J, Winnick A, Jotkowitz A. Placebos in the era of open-label trials: An update for clinicians. Eur J Clin Invest 2019; 49:e13038. [PMID: 30316203 DOI: 10.1111/eci.13038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/07/2018] [Accepted: 10/10/2018] [Indexed: 12/19/2022]
Abstract
Placebos have been used extensively by vast numbers of physicians, in a majority of clinical trials. Placebo effects involve behavioural, psychological and genetic factors and have been subject to ethical controversies stemming from the use of deception in treating patients. The patient-physician encounter, endogenous pharmacological pathways, personality traits and genetic diversity have all been reported to be key players in placebo responses. In the last decade, a new methodological paradigm of placebo research has emerged, using open-label placebos to investigate their effects which showed promising results for various common medical conditions. In this review, we will summarize the current body of evidence on placebos in clinical practice, with a view to open-label placebo trials in particular. It is our view that future larger-scale randomized blinded open placebo trials will benefit physicians and improve patient outcomes.
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Affiliation(s)
- Iftach Sagy
- Soroka University Medical Center and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel.,Clinical Research Center, Soroka University Medical Center, Beer-Sheva, Israel
| | - Jonathan Abres
- Soroka University Medical Center and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Ariel Winnick
- Soroka University Medical Center and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Alan Jotkowitz
- Soroka University Medical Center and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
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Weimer K, Hahn E, Mönnikes N, Herr AK, Stengel A, Enck P. Are Individual Learning Experiences More Important Than Heritable Tendencies? A Pilot Twin Study on Placebo Analgesia. Front Psychiatry 2019; 10:679. [PMID: 31620030 PMCID: PMC6759638 DOI: 10.3389/fpsyt.2019.00679] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 08/22/2019] [Indexed: 12/11/2022] Open
Abstract
Objective: Predicting who will be a placebo responder is a prerequisite to maximize placebo effects in pain treatment and to minimize them in clinical trials. First evidence exists that genetics could affect placebo effects. However, a classical twin study to estimate the relative contribution of genetic influences compared to common and individual environmental influences in explaining interindividual differences in placebo responsiveness has yet not been performed. Methods: In a first explorative twin study, 25 monozygotic (MZ) and 14 dizygotic (DZ) healthy twin pairs (27.5 ± 7.7 years; 73% female) were conditioned to the efficacy of a placebo analgesic ointment with an established heat pain paradigm on their non-dominant arm. Placebo analgesia was then tested on their dominant arm. Furthermore, warmth detection thresholds (WDTs) and heat pain thresholds (HPTs) were assessed, and participants filled in questionnaires for the assessment of psychological traits such as depression, anxiety, optimism, pain catastrophizing, and sensitivity to reward and punishment. Their expectations were determined with a visual analog scale. Results: There was a small but significant placebo analgesic effect in both MZ and DZ twins. Estimates of heritability were moderate for WDT only but negligible for HPT, the conditioning response, and placebo analgesia. Common environment did not explain any variance, and the individual environment explained the largest parts. Therefore, the placebo analgesia response can be seen as influenced by individual learning experiences during the conditioning procedure, whereas other variables assessed were not associated. Conclusions: Compared to the individual learning experience, genetic influences seem to play a minor role in explaining variation in placebo analgesia in this experimental paradigm. However, our results are restricted to placebo effects through conditioning on pain in healthy volunteers and should be replicated in larger samples and in patients. Furthermore, potential gene-environment interactions should be further investigated.
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Affiliation(s)
- Katja Weimer
- Department of Psychosomatic Medicine and Psychotherapy, Ulm University Medical Center, Ulm, Germany.,Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
| | - Elisabeth Hahn
- Department of Psychology, Saarland University, Saarbruecken, Germany
| | - Nils Mönnikes
- Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Ann-Kathrin Herr
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
| | - Andreas Stengel
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany.,Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Paul Enck
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
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Abstract
In this review, we explored different ways of controlling the placebo effects in clinical trials and described various factors that may increase/decrease the placebo effect in randomized placebo-controlled trials. These factors can be subdivided into four groups, and while not all factors are effective in every study and under all clinical conditions, they show on the whole that - even under the ideal condition of drug therapy, where blinded placebo provision is much easier and warranted than in, e.g., psychotherapy - many factors need to be controlled to ascertain that the goal of the clinical trials, fair assessment of superiority of the drug over placebo in placebo-controlled trials and fair assessment of non-inferiority of the drug compared to another drug in comparator trials, is reached. Ignorance towards the placebo effect, which was common in the past, is no longer acceptable; instead, it should be the goal of all therapeutic trials to minimize the placebo effect in clinical trials, while utilizing and maximizing it in clinical routine.
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Affiliation(s)
- Paul Enck
- Department of Internal Medicine VI: Psychosomatic Medicine and Psychotherapy , University Hospital Tübingen, Tübingen, Germany.
| | - Sibylle Klosterhalfen
- Department of Internal Medicine VI: Psychosomatic Medicine and Psychotherapy , University Hospital Tübingen, Tübingen, Germany
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De Pascalis V, Scacchia P. The influence of reward sensitivity, heart rate dynamics and EEG-delta activity on placebo analgesia. Behav Brain Res 2018; 359:320-332. [PMID: 30439452 DOI: 10.1016/j.bbr.2018.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/10/2018] [Accepted: 11/08/2018] [Indexed: 02/07/2023]
Abstract
Personality traits have been shown to interact with environmental cues to modulate biological responses including treatment responses, and potentially having a role in the formation of placebo effects. Here we used the Reinforcement Sensitivity Theory Personality Questionnaire (RST-PQ) to identify personality traits that predict placebo analgesic responding. Cardiac inter-beat (RR) time series and electroencephalographic (EEG) band oscillations were recorded from healthy women in a cold-pain (Pain) and placebo analgesia (PA) condition. The measures of Hypnotizability, and self-reported ratings of Hypnotic Depth, Motivation, Pain Expectation, Involuntariness in PA responding, Pain and Distress intensity were obtained. Separate principal components factor analyses with varimax rotation were performed on summarized heart rate variability (HRV) measures of time, frequency, nonlinear Complexity, and EEG-band activity. Both analyses yielded a similar three-factor solution including Frequency HRV (factor-1), Complexity HRV dynamics (factor-2), and time HRV & EEG-delta activity (factor-3). Reward Interest sub-trait of the Behavioral Approach System (BAS-RI), Pain Expectation, Involuntariness in PA responding, and Hypnotic Depth were positively associated, whereas negative changes in time-HRV & EEG-delta scores were associated with Pain Reduction. Multiple mediation analyses disclosed that BAS-RI, potentially served by the dopaminergic system, through Involuntariness in PA responding can alter placebo responding to laboratory pain. Our results also show that a linear compound of HR slowing and higher EEG delta activity during PA explains a substantial proportion of the variance in placebo analgesic responses. Future studies should examine the potential role that these individual difference measures may play in patient responsiveness to treatments for clinical pain.
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Affiliation(s)
- V De Pascalis
- Department of Psychology "La Sapienza" University of Rome, Italy.
| | - P Scacchia
- Department of Psychology "La Sapienza" University of Rome, Italy
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Köteles F, Babulka P, Szemerszky R, Dömötör Z, Boros S. Inhaled peppermint, rosemary and eucalyptus essential oils do not change spirometry in healthy individuals. Physiol Behav 2018; 194:319-323. [DOI: 10.1016/j.physbeh.2018.06.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 06/14/2018] [Accepted: 06/14/2018] [Indexed: 10/14/2022]
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Brain and psychological determinants of placebo pill response in chronic pain patients. Nat Commun 2018; 9:3397. [PMID: 30209286 PMCID: PMC6135815 DOI: 10.1038/s41467-018-05859-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 07/12/2018] [Indexed: 12/18/2022] Open
Abstract
The placebo response is universally observed in clinical trials of pain treatments, yet the individual characteristics rendering a patient a ‘placebo responder’ remain unclear. Here, in chronic back pain patients, we demonstrate using MRI and fMRI that the response to placebo ‘analgesic’ pills depends on brain structure and function. Subcortical limbic volume asymmetry, sensorimotor cortical thickness, and functional coupling of prefrontal regions, anterior cingulate, and periaqueductal gray were predictive of response. These neural traits were present before exposure to the pill and most remained stable across treatment and washout periods. Further, psychological traits, including interoceptive awareness and openness, were also predictive of the magnitude of response. These results shed light on psychological, neuroanatomical, and neurophysiological principles determining placebo response in RCTs in chronic pain patients, and they suggest that the long-term beneficial effects of placebo, as observed in clinical settings, are partially predictable. People vary in the extent to which they feel better after taking an inert, placebo, treatment, but the basis for individual placebo response is unclear. Here, the authors show how brain structural and functional variables, as well as personality traits, predict placebo response in those with chronic back pain.
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Abstract
OBJECTIVE Naturalistic studies suggest that expectation of adverse experiences such as pain exerts particularly strong effects on anxious youth. In healthy adults, expectation influences the experience of pain. The current study uses experimental methods to compare the effects of expectation on pain among adults, healthy youth, and youth with an anxiety disorder. METHODS Twenty-three healthy adults, 20 healthy youth, and 20 youth with an anxiety disorder underwent procedures in which auditory cues were paired with noxious thermal stimulation. Through instructed conditioning, one cue predicted low-pain stimulation and the other predicted high-pain stimulation. At test, each cue was additionally followed by a single temperature calibrated to elicit medium pain ratings. We compared cue-based expectancy effects on pain across the three groups, based on cue effects on pain elicited on medium heat trials. RESULTS Across all groups, as expected, participants reported greater pain with increasing heat intensity (β = 2.29, t(41) = 29.94, p < .001). Across all groups, the critical medium temperature trials were rated as more painful in the high- relative to low-expectancy condition (β = 1.72, t(41) = 10.48, p < .001). However, no evidence of between-group differences or continuous associations with age or anxiety was observed. CONCLUSIONS All participants showed strong effects of expectancy on pain. No influences of development or anxiety arose. Complex factors may influence associations among anxiety, development, and pain reports in naturalistic studies. Such factors may be identified using experiments that employ more complex, yet controlled manipulations of expectancy or assess neural correlates of expectancy.
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Kessels R, Mozer R, Bloemers J. Methods for assessing and controlling placebo effects. Stat Methods Med Res 2017; 28:1141-1156. [DOI: 10.1177/0962280217748339] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The placebo serves as an indispensable control in many randomized trials. When analyzing the benefit of a new treatment, researchers are often confronted with large placebo effects that diminish the treatment effect. Various alternative methods have been proposed for analyzing placebo and treatment effects in studies where large placebo effects are expected or have already occurred. This paper presents an overview of methodological work that has been proposed for assessing and/or controlling for placebo effects in randomized trials. Throughout this paper, two main approaches are discussed. The first approach considers designs that represent alternatives to the classical placebo-controlled randomized trial design. Separately, the second approach considers adopting new methods for the statistical analysis of placebo and treatment effects to be implemented after the data have been collected using a classical randomized trial design.
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Affiliation(s)
- Rob Kessels
- Emotional Brain B.V., Almere, the Netherlands
| | - Reagan Mozer
- Department of Statistics, Harvard University, Cambridge, MA, USA
| | - Jos Bloemers
- Emotional Brain B.V., Almere, the Netherlands
- Utrecht Institute for Pharmaceutical Sciences and Rudolf Magnus Institute of Neuroscience, Utrecht University, Utrecht, The Netherlands
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Lower Placebo Responses After Long-Term Exposure to Fibromyalgia Pain. THE JOURNAL OF PAIN 2017; 18:835-843. [DOI: 10.1016/j.jpain.2017.02.434] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 02/13/2017] [Accepted: 02/21/2017] [Indexed: 12/14/2022]
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Coste J, Montel S. Placebo-related effects: a meta-narrative review of conceptualization, mechanisms and their relevance in rheumatology. Rheumatology (Oxford) 2017; 56:334-343. [PMID: 27477808 DOI: 10.1093/rheumatology/kew274] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Indexed: 12/19/2022] Open
Abstract
For decades in medicine, the placebo effect has been conceptualized as a subjective psychological effect associated with an inert substance and considered to be a nuisance noise in the assessment of therapeutic effects in clinical trials. However, research on placebo has undergone substantial developments since the mid-1980s in several fields of knowledge (including methodology, psychology and neurosciences) that challenge this traditional view. Using a meta-narrative approach, this review of conceptualizations, determinants, mechanisms and models of placebo effects shows that placebo effects are genuine biopsychosocial phenomena strongly affected by context and factors surrounding the patient and treatments. Psychological experiments and neurobiological and neuroimaging studies have identified various types of placebo responses, driven by different mechanisms (especially but not only expectation and conditioning) and associated with different chemical, structural and functional features. Insights into the mechanisms involved in placebo responses have led to opportunities for ethical enhancements of these mechanisms in clinical practice, notably by improving the patient-doctor interaction and refining the therapeutic ritual. These developments should be carefully considered in rheumatology settings, in which placebo effects are both prevalent and significant, with the potential to improve patient care.
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Affiliation(s)
- Joël Coste
- APEMAC, EA 4360, Paris Descartes University, University of Lorraine.,Biostatistics and Epidemiology Unit, Hôtel Dieu, Assistance Publique, Hôpitaux de Paris
| | - Sébastien Montel
- APEMAC, EA 4360, Paris Descartes University, University of Lorraine.,Department of Psychology, University Paris Saint Denis, Paris, France
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Unsolved, Forgotten, and Ignored Features of the Placebo Response in Medicine. Clin Ther 2017; 39:458-468. [DOI: 10.1016/j.clinthera.2016.11.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 12/14/2022]
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Hartogsohn I. Set and setting, psychedelics and the placebo response: An extra-pharmacological perspective on psychopharmacology. J Psychopharmacol 2016; 30:1259-1267. [PMID: 27852960 DOI: 10.1177/0269881116677852] [Citation(s) in RCA: 220] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Placebo response theory and set and setting theory are two fields which examine how non-biological factors shape the response to therapy. Both consider factors such as expectancy, preparation and beliefs to be crucial for understanding the extra-pharmacological processes which shape the response to drugs. Yet there are also fundamental differences between the two theories. Set and setting concerns itself with response to psychoactive drugs only; placebo theory relates to all therapeutic interventions. Placebo theory is aimed at medical professionals; set and setting theory is aimed at professionals and drug users alike. Placebo theory is primarily descriptive, describing how placebo acts; set and setting theory is primarily prescriptive, educating therapists and users on how to control and optimize the effects of drugs. This paper examines how placebo theory and set and setting theory can complement and benefit each other, broadening our understanding of how non-biological factors shape response to drugs and other treatment interventions.
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Affiliation(s)
- Ido Hartogsohn
- Science, Technology and Society Program, Bar Ilan University, Ramat Gan, Israel
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Tétreault P, Mansour A, Vachon-Presseau E, Schnitzer TJ, Apkarian AV, Baliki MN. Brain Connectivity Predicts Placebo Response across Chronic Pain Clinical Trials. PLoS Biol 2016; 14:e1002570. [PMID: 27788130 PMCID: PMC5082893 DOI: 10.1371/journal.pbio.1002570] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 09/23/2016] [Indexed: 12/17/2022] Open
Abstract
Placebo response in the clinical trial setting is poorly understood and alleged to be driven by statistical confounds, and its biological underpinnings are questioned. Here we identified and validated that clinical placebo response is predictable from resting-state functional magnetic-resonance-imaging (fMRI) brain connectivity. This also led to discovering a brain region predicting active drug response and demonstrating the adverse effect of active drug interfering with placebo analgesia. Chronic knee osteoarthritis (OA) pain patients (n = 56) underwent pretreatment brain scans in two clinical trials. Study 1 (n = 17) was a 2-wk single-blinded placebo pill trial. Study 2 (n = 39) was a 3-mo double-blinded randomized trial comparing placebo pill to duloxetine. Study 3, which was conducted in additional knee OA pain patients (n = 42), was observational. fMRI-derived brain connectivity maps in study 1 were contrasted between placebo responders and nonresponders and compared to healthy controls (n = 20). Study 2 validated the primary biomarker and identified a brain region predicting drug response. In both studies, approximately half of the participants exhibited analgesia with placebo treatment. In study 1, right midfrontal gyrus connectivity best identified placebo responders. In study 2, the same measure identified placebo responders (95% correct) and predicted the magnitude of placebo's effectiveness. By subtracting away linearly modeled placebo analgesia from duloxetine response, we uncovered in 6/19 participants a tendency of duloxetine enhancing predicted placebo response, while in another 6/19, we uncovered a tendency for duloxetine to diminish it. Moreover, the approach led to discovering that right parahippocampus gyrus connectivity predicts drug analgesia after correcting for modeled placebo-related analgesia. Our evidence is consistent with clinical placebo response having biological underpinnings and shows that the method can also reveal that active treatment in some patients diminishes modeled placebo-related analgesia. Trial Registration ClinicalTrials.gov NCT02903238 ClinicalTrials.gov NCT01558700.
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Affiliation(s)
- Pascal Tétreault
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Ali Mansour
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Etienne Vachon-Presseau
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Thomas J. Schnitzer
- Department of Physical Medicine and Rehabilitation, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
- Department of Internal Medicine, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - A. Vania Apkarian
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
- Department of Physical Medicine and Rehabilitation, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
- Department of Anesthesia, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
- * E-mail: (AVA); (MNB)
| | - Marwan N. Baliki
- Department of Physical Medicine and Rehabilitation, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States of America
- Rehabilitation Institution of Chicago, Chicago, Illinois, United States of America
- * E-mail: (AVA); (MNB)
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Rosén A, Yi J, Kirsch I, Kaptchuk TJ, Ingvar M, Jensen KB. Effects of subtle cognitive manipulations on placebo analgesia - An implicit priming study. Eur J Pain 2016; 21:594-604. [PMID: 27748563 PMCID: PMC5363385 DOI: 10.1002/ejp.961] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2016] [Indexed: 12/17/2022]
Abstract
Background Expectancy is widely accepted as a key contributor to placebo effects. However, it is not known whether non‐conscious expectancies achieved through semantic priming may contribute to placebo analgesia. In this study, we investigated if an implicit priming procedure, where participants were unaware of the intended priming influence, affected placebo analgesia. Methods In a double‐blind experiment, healthy participants (n = 36) were randomized to different implicit priming types; one aimed at increasing positive expectations and one neutral control condition. First, pain calibration (thermal) and a credibility demonstration of the placebo analgesic device were performed. In a second step, an independent experimenter administered the priming task; Scrambled Sentence Test. Then, pain sensitivity was assessed while telling participants that the analgesic device was either turned on (placebo) or turned off (baseline). Pain responses were recorded on a 0–100 Numeric Response Scale. Results Overall, there was a significant placebo effect (p < 0.001), however, the priming conditions (positive/neutral) did not lead to differences in placebo outcome. Prior experience of pain relief (during initial pain testing) correlated significantly with placebo analgesia (p < 0.001) and explained 34% of placebo variance. Trait neuroticism correlated positively with placebo analgesia (p < 0.05) and explained 21% of placebo variance. Conclusions Priming is one of many ways to influence behaviour, and non‐conscious activation of positive expectations could theoretically affect placebo analgesia. Yet, we found no SST priming effect on placebo analgesia. Instead, our data point to the significance of prior experience of pain relief, trait neuroticism and social interaction with the treating clinician. Significance Our findings challenge the role of semantic priming as a behavioural modifier that may shape expectations of pain relief, and affect placebo analgesia.
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Affiliation(s)
- A Rosén
- Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - J Yi
- Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - I Kirsch
- Program in Placebo Studies and Therapeutic Encounters, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
| | - T J Kaptchuk
- Program in Placebo Studies and Therapeutic Encounters, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
| | - M Ingvar
- Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - K B Jensen
- Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden.,Program in Placebo Studies and Therapeutic Encounters, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
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Future Targets for Female Sexual Dysfunction. J Sex Med 2016; 13:1147-65. [DOI: 10.1016/j.jsxm.2016.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/22/2016] [Accepted: 05/27/2016] [Indexed: 12/18/2022]
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Darragh M, Booth RJ, Consedine NS. 'Oxytocin' for the outwardly oriented: Evidence for interactive effects in placebo responding. J Psychosom Res 2016; 83:10-5. [PMID: 27020070 DOI: 10.1016/j.jpsychores.2016.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 02/02/2016] [Accepted: 02/05/2016] [Indexed: 12/19/2022]
Abstract
OBJECTIVE In order to harness the placebo effect for clinical benefit, more research is needed to determine who might be responsive to a placebo treatment. Recently, a two-faceted Transactional Model of Placebo Responding (TMPR) was offered, which suggests different personality types might respond to different contextual cues. The current study directly tested this model by manipulating treatment descriptors to match the two purported facets of responsiveness. METHODS Physically healthy volunteers (N=77) experiencing life stress were randomised to either the: (1) wait-list control, (2) 'serotonin treatment' group; or (3) 'oxytocin treatment' group. Both treatment groups received an 'antistress' intranasal spray (placebo). The 'serotonin' and 'oxytocin' treatments were described to appeal to the two purported facets responsiveness set out in the TMPR, inward and outward orientation. The BIS/BAS scale was used as proxies for inward (BIS) and outward (BAS) orientation. It was hypothesised that high BAS types would be more responsive to the 'oxytocin' and high BIS types would be more responsive to the 'serotonin'. RESULTS Findings provide partial support for hypotheses, with high but not low BAS types having a greater response to the 'oxytocin' placebo; but the pattern of responses from high BIS types were contrary to predictions. CONCLUSIONS Findings indicate interactions between personality type and environmental cues may contribute to placebo responding, but more research is needed to investigate possible operationalisations of responsiveness and the contextual cues to which different types may respond.
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Affiliation(s)
| | - Roger J Booth
- Department of Molecular Medicine & Pathology, New Zealand
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