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Schaefer M, Kühnel A, Enge S. Open-label placebos reduce weight in obesity: a randomized controlled trial. Sci Rep 2024; 14:21311. [PMID: 39266589 PMCID: PMC11392943 DOI: 10.1038/s41598-024-69866-7] [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: 04/17/2024] [Accepted: 08/09/2024] [Indexed: 09/14/2024] Open
Abstract
Obesity is a major public health problem worldwide. Different approaches are known to face this problem, for example, dieting, surgery, or drug interventions. It has also been shown that placebos may help to reduce weight and hunger feelings, but the use of placebos is linked to problems with respect to the patient-healthcare-provider relationship. However, recent studies demonstrated that even placebos without deception (open-label placebos) affect symptoms such as pain, anxiety, or emotional distress. Here we aimed to examine whether an open-label placebo may help to lose weight in obesity. Our study included fifty-seven overweight and obese patients who aimed to lose weight using a combination of diet and sports. Patients were randomly divided into two groups. Participants in the open-label placebo group received two placebos each day. A treatment-as-usual group received no pills. Primary outcome included changes of body weight. Secondary outcomes were change of eating behavior and self-management abilities. After 4 weeks we found that participants in the open-label placebo condition lost more weight than the treatment-as-usual group. Furthermore, OLP treatment affected eating behavior. No effects for self-management abilities were found. Although further research is necessary, open-label placebos might help individuals to lose weight.
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Affiliation(s)
- Michael Schaefer
- MSB Medical School Berlin, Rüdesheimer Str. 50, 14197, Berlin, Germany.
| | - Anja Kühnel
- MSB Medical School Berlin, Rüdesheimer Str. 50, 14197, Berlin, Germany
| | - Sören Enge
- MSB Medical School Berlin, Rüdesheimer Str. 50, 14197, Berlin, Germany
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McCartney M, Cohen D. Does the METHOD study show that ZOE works? BMJ 2024; 386:q1720. [PMID: 39095073 DOI: 10.1136/bmj.q1720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
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Potthoff J, Schienle A. Effects of (non)deceptive placebos on reported sleep quality and food cue reactivity. J Sleep Res 2024; 33:e13947. [PMID: 37221456 DOI: 10.1111/jsr.13947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/28/2023] [Accepted: 05/05/2023] [Indexed: 05/25/2023]
Abstract
A lack of sleep can increase appetite, particularly for high-calorie food. The current study tested the effects of an open-label placebo for improving sleep quality and reducing food cue reactivity. In open-label placebo interventions, placebo recipients are informed that they are receiving a placebo without a pharmacologically active substance. Participants (n = 150) were randomly allocated to one of three groups that received either an open-label placebo to improve sleep quality, a deceptive placebo ("melatonin"), or no placebo. The placebo was administered daily before bedtime for 1 week. Sleep quality and reactivity to high-calorie food cues (appetite, visual attention to food images) were assessed. The deceptive placebo (but not the open-label placebo) reduced reported sleep-onset latency. The open-label placebo decreased perceived sleep efficiency. The placebo interventions did not change food cue reactivity. This study demonstrated that open-label placebos do not present an alternative to deceptive placebos for improving sleep quality. The undesirable open-label placebo effects found warrant further exploration.
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Affiliation(s)
- Jonas Potthoff
- Institute of Psychology, University of Graz, Graz, Austria
| | - Anne Schienle
- Institute of Psychology, University of Graz, Graz, Austria
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Khalid I, Rodrigues B, Dreyfus H, Frileux S, Meissner K, Fossati P, Hare TA, Schmidt L. Mapping expectancy-based appetitive placebo effects onto the brain in women. Nat Commun 2024; 15:248. [PMID: 38172100 PMCID: PMC10764825 DOI: 10.1038/s41467-023-44569-1] [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: 02/09/2023] [Accepted: 12/15/2023] [Indexed: 01/05/2024] Open
Abstract
Suggestions about hunger can generate placebo effects on hunger experiences. But, the underlying neurocognitive mechanisms are unknown. Here, we show in 255 women that hunger expectancies, induced by suggestion-based placebo interventions, determine hunger sensations and economic food choices. Functional magnetic resonance imaging in a subgroup (n = 57/255) provides evidence that the strength of expecting the placebo to decrease hunger moderates medial prefrontal cortex activation at the time of food choice and attenuates ventromedial prefrontal cortex (vmPFC) responses to food value. Dorsolateral prefrontal cortex activation linked to interference resolution formally mediates the suggestion-based placebo effects on hunger. A drift-diffusion model characterizes this effect by showing that the hunger suggestions bias participants' food choices and how much they weigh tastiness against the healthiness of food, which further moderates vmPFC-dlPFC psychophysiological interactions when participants expect decreased hunger. Thus, suggestion-induced beliefs about hunger shape hunger addressing economic choices through cognitive regulation of value computation within the prefrontal cortex.
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Affiliation(s)
- Iraj Khalid
- Sorbonne University, Institut du Cerveau-Paris Brain Institute - ICM, INSERM, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Belina Rodrigues
- Sorbonne University, Institut du Cerveau-Paris Brain Institute - ICM, INSERM, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Hippolyte Dreyfus
- Sorbonne University, Institut du Cerveau-Paris Brain Institute - ICM, INSERM, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Solène Frileux
- Sorbonne University, Institut du Cerveau-Paris Brain Institute - ICM, INSERM, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Karin Meissner
- Institute of Medical Psychology, Medical Faculty, LMU Munich, Munich, Germany
- Division of Health Promotion, Faculty of Applied Natural Sciences and Health, Coburg University of Applied Sciences and Arts, Coburg, Germany
| | - Philippe Fossati
- Sorbonne University, Institut du Cerveau-Paris Brain Institute - ICM, INSERM, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
- Adult Psychiatry Department, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Todd Anthony Hare
- Zürich Center for Neuroeconomics, Department of Economics, University of Zürich, Zürich, Switzerland
| | - Liane Schmidt
- Sorbonne University, Institut du Cerveau-Paris Brain Institute - ICM, INSERM, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France.
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Unger I, Schienle A. Taking Placebos as Needed to Reduce Appetite: A Randomized Controlled Trial with Ecological Momentary Assessment. Behav Sci (Basel) 2023; 13:bs13030207. [PMID: 36975231 PMCID: PMC10045637 DOI: 10.3390/bs13030207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 03/08/2023] Open
Abstract
Placebos can reduce appetite. However, when placebos are prescribed over a longer period of time, compliance and response rates are not always satisfactory. A new administration approach ‘as needed’ was tested to improve adherence to placebo treatment and its effectiveness. Participants could decide on the time of placebo intake (when their appetite had increased substantially). A randomized controlled trial was conducted over seven days. The participants were allocated to one of two groups: a placebo group (PG; n = 41) or a control group with no placebo treatment (CG; n = 34). During the intervention, participants used a mobile phone application to rate their daily appetite, mood, and the occurrence of binge-eating episodes in their normal environment. The placebo effect was short-lived; the placebo reduced self-reported appetite only on days 1 and 2 of the trial. The placebo neither influenced mood nor binge-eating frequency. This study found an app-assisted approach with continuous monitoring to be helpful for identifying the temporal course of the placebo response. Future placebo trials should implement this method.
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Neumann M, Wirtz MA, Lutz G, Ernesti A, Edelhäuser F. Why context matters when changing the diet: A narrative review of placebo, nocebo, and psychosocial context effects and implications for outcome research and nutrition counselling. Front Nutr 2022; 9:937065. [PMID: 36386910 PMCID: PMC9650541 DOI: 10.3389/fnut.2022.937065] [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: 05/05/2022] [Accepted: 10/11/2022] [Indexed: 09/19/2023] Open
Abstract
Placebo (PE) and nocebo effects (NE) have been subjects of systematic research in medicine and psychotherapy for many decades to distinguish between the (specific) pharmacological effect of medication and the (unspecific) effect of the context. Despite this significant research, the awareness, operationalisation, and reflection of the multiplicity of PE, NE, and psychosocial context effects (PSCE) is currently limited when researching outcomes of diet changes in studies without randomisation and placebo control. This neglection is critical as it could systematically influence outcomes by moderating and mediating them and thus reducing the validity and evidence base of these studies. Therefore, we performed a (non-systematic) narrative review (NR) on the following objectives: (1) present a concise overview about the relevance of PE, NE, and PSCE in medicine and nutrition research; (2) review the current state of research on reflecting context effects when studying diet changes; (3) provide useful theoretical foundations via consideration and integration of micro- and macro context effects; (4) operationalise as hypotheses the potential PE, NE, and PSCE which are specific for researching diet changes; and (5) derive their impact for future research as well as for nutrition counselling. The electronic search in this NR for objective (2) identified N = 5 publications and for objective (4) we found N = 61 articles retrieved in the first round of search, additional references were identified by a manual and snowball search among the cited references resulting finally in N = 37. This NR offers a synoptical basis to foster awareness and operationalisation of a variety of PE, NE, and PSCE. Interdisciplinary research teams should monitor these factors using, e.g., qualitative, mixed-method studies, process evaluation, item bank approaches, moderator and mediator analysis that might reveal substantially new insights, and outcomes of relevance to science and nutrition counselling. Nevertheless, the present NR has several limitations, especially as it is non-systematic, because it is a very heterogeneous field of research, in which the topic we are investigating is usually regarded as marginal and subordinate. Therefore, future research should conduct systematic reviews and particularly theory-based primary studies (experimental research) on hypotheses of PE, NE, and PSCE in outcome research in diet changes.
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Affiliation(s)
- Melanie Neumann
- Department of Medicine, Faculty of Health, Integrated Curriculum for Anthroposophic Medicine (ICURAM) and Institute of Integrative Medicine, Witten/Herdecke University, Witten, Germany
| | | | - Gabriele Lutz
- Department of Psychosomatic Medicine, Gemeinschaftskrankenhaus Herdecke, Herdecke, Germany
- Department of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Alina Ernesti
- Department of Psychology and Psychotherapy, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Friedrich Edelhäuser
- Department of Medicine, Faculty of Health, Integrated Curriculum for Anthroposophic Medicine (ICURAM) and Institute of Integrative Medicine, Witten/Herdecke University, Witten, Germany
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Schlintl C, Schienle A. Effects of Coloring Food Images on the Propensity to Eat: A Placebo Approach With Color Suggestions. Front Psychol 2020; 11:589826. [PMID: 33192928 PMCID: PMC7658407 DOI: 10.3389/fpsyg.2020.589826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/07/2020] [Indexed: 12/20/2022] Open
Abstract
Background Research findings on the appetite-enhancing effect of the color red and the appetite-reducing effect of blue have been inconsistent. The present study used a placebo approach and investigated whether verbal suggestions can enhance color-appetite effects. Method A total of 448 women participated in two experiments. They viewed images with differently colored sweet foods (original color, blue, red, colorless (black-and-white); experiment 1; n = 217) or sweet foods on blue, red, white, and gray backgrounds; experiment 2; n = 231). Before viewing the images, half of the participants received information about the effects of red and blue food color on appetite (color suggestion). The other half received no suggestion. For each of the experiments, the reported propensity to eat (food wanting) was compared between the conditions. Results All colored food items were associated with a lower propensity to eat compared to the food items in the original color. The color suggestion (compared to no suggestion) additionally decreased the propensity to eat blue and black-and-white food items. Colored backgrounds did not influence food wanting. Conclusion This study demonstrated that red and blue coloring of visual food cues did not have the predicted effects on food wanting. However, the combination of specific food colors with specific color suggestions might be useful to change the willingness to eat sweet products.
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Affiliation(s)
- Carina Schlintl
- Department of Clinical Psychology, University of Graz, Graz, Austria
| | - Anne Schienle
- Department of Clinical Psychology, University of Graz, Graz, Austria
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Brown S, Duncan J, Crabtree D, Powell D, Hudson M, Allan J. We are what we (think we) eat: The effect of expected satiety on subsequent calorie consumption. Appetite 2020; 152:104717. [DOI: 10.1016/j.appet.2020.104717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 01/30/2023]
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Maximizing placebo response in neurological clinical practice. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 153:71-101. [PMID: 32563294 DOI: 10.1016/bs.irn.2020.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The placebo effect is a widely recognized phenomenon in clinical research, with a negative perception that it could hide the "true" drug effect. In clinical care its positive potential to increase known drug effects has been neglected for too long. The placebo and nocebo responses have been described in many neurologic disorders such as Parkinson's, Huntington's and Alzheimer's diseases, restless leg syndrome, tics, essential tremor, dystonia, functional movement disorders, neuropathic pain, headaches, migraine, amyotrophic lateral sclerosis, myasthenia gravis, chronic inflammatory demyelinating polyneuropathy, multiple sclerosis and epilepsy. Knowledge regarding placebo mechanisms and their consequences on clinical outcome have greatly improved over the last two decades. This evolution has led to reconsiderations of the importance of placebo response in the clinic and has given several clues on how to improve it in daily practice. In this chapter, we first illustrate "why," e.g. the reasons (relevance to clinical practice, help in differential diagnosis/treatment of psychogenic movements, clinical impact, proven neurobiological grounds, health economic potential), and "how," e.g. the means (increase patients' knowledge, increase learning, improve patient-doctor relationship, increase Hawthorne effect, increase positive/decrease negative expectations (the Rosenthal effect), personalize placebo response), the placebo should be maximized (and nocebo avoided) in neurological clinical practice. Future studies regarding more specific neurobiological mechanisms will allow a finer tuning of placebo response in clinical practice. The use of placebo in clinical practice raises ethical issues, and a recent expert consensus regarding placebo use in the clinic is a first step to future guidelines necessary to this field.
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Potthoff J, Jurinec N, Schienle A. Placebo Effects on Visual Food Cue Reactivity: An Eye-Tracking Investigation. Front Psychiatry 2019; 10:525. [PMID: 31396116 PMCID: PMC6667658 DOI: 10.3389/fpsyt.2019.00525] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 07/03/2019] [Indexed: 11/22/2022] Open
Abstract
Background: Enhanced visual food cue reactivity has been associated with overeating and weight gain. Due to the increasing prevalence of high-fat food images that we are constantly exposed to in both the real and the virtual world, methods that are able to reduce the reactivity to these types of cues are urgently needed. This eye-tracking study investigated whether food cue reactivity, especially toward high-caloric food, can be reduced with a placebo intervention. Method: Fifty-two women [mean body mass index (BMI) = 23.5] were presented with pictures depicting combinations of food (high-caloric, low-caloric) and non-food items, which were shown once with and once without a placebo in a repeated-measures design. The placebo was a pill introduced as a medication targeting peptide YY that is able to reduce appetite specifically for high-caloric food. Gaze data (dwell time, fixations) and self-reported appetite were assessed during the two eye-tracking sessions (with/without placebo). Results: The placebo reduced general appetite as well as specific appetite for the depicted food items. Additionally, the placebo decreased the percentage of fixations and dwell time on the food images. The placebo was not able to specifically change visual food cue reactivity to high-caloric stimuli but reduced responses to both high-caloric and low-caloric food. Reported appetite reduction and weight concerns were positively associated with the placebo-related decrease in visual attention for food. Conclusions: The placebo was able to reduce visual food cue reactivity. This finding demonstrates that placebos are able to alter early visual-attentional processes.
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Affiliation(s)
- Jonas Potthoff
- Department of Clinical Psychology, University of Graz, Graz, Austria
| | - Nina Jurinec
- Department of Clinical Psychology, University of Graz, Graz, Austria
| | - Anne Schienle
- Department of Clinical Psychology, University of Graz, Graz, Austria
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