Medication regimens using conditioning via variable reinforcement have shown similar or improved therapeutic effects as full pharmacological treatment, but evidence in patient populations is scarce... Show moreMedication regimens using conditioning via variable reinforcement have shown similar or improved therapeutic effects as full pharmacological treatment, but evidence in patient populations is scarce. This proof-of-principle double-blind randomized clinical trial examined whether treatment effects in recent-onset rheumatoid arthritis (RA) can be optimized through pharmacological conditioning. After four months of standardized treatment (n = 46), patients in clinical remission (n = 19) were randomized to the Control group (C), continuing standardized treatment (n = 8), or the Pharmacological Conditioning (PC) group, receiving variable treatment according to conditioning principles (n = 11). After eight months, treatment was tapered and discontinued linearly (C) or variably (PC). Standard treatment led to large improvements in disease activity and HRQoL in both groups. The groups did not differ in the percentage of drug-free clinical remission obtained after conditioning or continued standard treatment. The PC group did show a larger decrease in self-reported disease activity (Cohen's d = 0.9) and a smaller increase in TNF-alpha levels (Cohen's d = 0.7) than the C group. During all phases, more differences between groups were found for the patients who followed protocol than for the intention-to-treat sample. Although the results are not conclusive, pharmacological conditioning may have some advantages in terms of disease progression and stability, especially during the conditioning phase, compared with standard clinical treatment. The effects may be particularly beneficial for patients who show a good initial response to increased medication dosages. Show less
This study investigated for the first time the effects of individual and combined application of 3 learning techniques (verbal suggestions, classical conditioning, and observational learning) on... Show moreThis study investigated for the first time the effects of individual and combined application of 3 learning techniques (verbal suggestions, classical conditioning, and observational learning) on placebo analgesia and extinction.Healthy participants (N = 206) were assigned to 8 different groups in which they were taught through either a verbal suggestion, a conditioning paradigm, a video observing someone, or any combination thereof that a placebo device (inactive transcutaneous electric nerve stimulation [TENS]) was capable of alleviating heat pain, whereas one group did not (control). Placebo analgesia was quantified as the within-group difference in experienced pain when the placebo device was (sham) 'activated' or 'inactivated' during equal pain stimuli, and compared between groups.Placebo analgesia was induced in groups with 2 or 3 learning techniques. Significantly stronger placebo analgesia was induced in the combination of all 3 learning techniques as compared to the individual learning techniques or control condition, underlining the additional contribution of 3 combined techniques. Extinction did not differ between groups. Furthermore, pain expectancies, but not state anxiety or trust, mediated placebo analgesia.Our findings emphasize the added value of combining 3 learning techniques to optimally shape expectancies that lead to placebo analgesia, which can be used in experimental and clinical settings. Perspective: This unique experimental study compared the individual versus combined effects of 3 important ways of learning (verbal suggestions, classical conditioning, and observational learning) on expectation-based pain relief. The findings indicate that placebo effects occurring in clinical practice could be optimally strengthened if healthcare providers apply these techniques in combination.(R) 2023 The Author(s). Published by Elsevier Inc. on behalf of United States Association for the Study of Pain, Inc This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Nocebo effects are adverse treatment outcomes that are not ascribed to active treatment components. Potentially, their magnitude might be higher in patients with chronic pain compared to healthy... Show moreNocebo effects are adverse treatment outcomes that are not ascribed to active treatment components. Potentially, their magnitude might be higher in patients with chronic pain compared to healthy controls since patients likely experience treatment failure more frequently. The current study investigated group differences in the induction and extinction of nocebo effects on pressure pain at baseline (N = 69) and 1-month follow-up (N = 56) in female patients with fibromyalgia and matched healthy controls. Nocebo effects were first experimentally induced via classical conditioning combined with instructions on the pain-increasing function of a sham transcutaneous electrical nerve stimulation device, then decreased via extinction. One month later, the same procedures were repeated to explore their stability. Results suggest that nocebo effects were induced in the healthy control group during baseline and follow-up. In the patient group, nocebo effects were only induced during follow-up, without clear group differences. Extinction was only observed during baseline in the healthy control group. Further comparisons of nocebo effects and extinction indicated no significant changes across sessions, possibly suggesting their overall magnitudes were stable over time and across groups. In conclusion, contrary to our expectations, patients with fibromyalgia did not have stronger nocebo hyperalgesia; instead, they might be less responsive to nocebo manipulations than healthy controls. Show less
Nocebo effects on pain are widely thought to be driven by negative expectations. This suggests that anticipatory processing, or some other form of top-down cognitive activity prior to the... Show moreNocebo effects on pain are widely thought to be driven by negative expectations. This suggests that anticipatory processing, or some other form of top-down cognitive activity prior to the experience of pain, takes place to form sensory-augmenting expectations. However, little is known about the neural markers of anticipatory processing for nocebo effects. In this event-related potential study on healthy participants (n = 42), we tested whether anticipatory processing for classically conditioned nocebo-augmented pain differed from pain without nocebo augmentation using stimulus preceding negativity (SPN), and Granger Causality (GC). SPN is a slow-wave ERP component thought to measure top-down processing, and GC is a multivariate time series analysis used to measure functional connectivity between brain regions. Fear of pain was assessed with the Fear of Pain Questionnaire-III and tested for correlation with SPN and GC metrics. We found evidence that both anticipatory processing measured with SPN and functional connectivity from frontal to temporoparietal brain regions measured with GC were increased for nocebo pain stimuli relative to control pain stimuli. Other GC node pairs did not yield significant effects, and a lag in the timing of nocebo pain stimuli limited interpretation of the results. No correlations with trait fear of pain measured after the conditioning procedure were detected, indicating that while differences in neural activity could be detected between the anticipation of nocebo and control pain trials, they likely were not related to fear. These results highlight the role that top-down processes play in augmenting sensory perception based on negative expectations before sensation occurs. Show less
Objective: The objective of this study was to investigate whether placebo effect induced by pharmacological conditioning with intranasal insulin can affect glucose, insulin, C-peptide, hunger, and... Show moreObjective: The objective of this study was to investigate whether placebo effect induced by pharmacological conditioning with intranasal insulin can affect glucose, insulin, C-peptide, hunger, and memory in patients with diabetes type 2 and healthy controls. Methods: Placebo effect was induced by pharmacological conditioning. Thirty-two older patients (mean age = 68.3 years) with diabetes type 2 and age- and sex-matched thirty-two healthy older adults (mean age = 67.8 years) were randomly assigned to a conditioned or a control group. On day 1, conditioned group received six administrations of intranasal insulin with a conditioned stimulus (CS; smell of rosewood oil), whereas the control group received a placebo with the CS. On day 2, both groups received a placebo spray with the CS. Glucose, insulin, and C-peptide were repeatedly measured in blood. Hunger and memory were assessed with validated measures. Results: Intranasal insulin stabilized dropping glucose levels in patients (B = 0.03, SE = 0.02, p = .027) and healthy men (B = 0.046, SE = 0.02, p = .021), and decreased C-peptide levels in healthy controls (B = 0.01, SE = 0.001, p = .008). Conditioning also prevented the drop of glucose levels but only in men (both healthy and patients; B = 0.001, SE = 0.0003, p = .024). Conditioning significantly decreased hunger in healthy participants (B = 0.31, SE = 0.09, p < .001). No effects were found on other measures. Conclusions: Placebo effect induced by conditioning with intranasal insulin modifies blood glucose levels and decreases hunger in older adults, but its effects depend on health status and sex. Insulin conditioning might be beneficial for groups suffering from intensive hunger but seems not be particularly suitable for blood glucose reduction.Trial Registration: Netherlands Trial Register, NL7783 Show less
ObjectiveThe objective of this study was to investigate whether placebo effect induced by pharmacological conditioning with intranasal insulin can affect glucose, insulin, C-peptide, hunger, and... Show moreObjectiveThe objective of this study was to investigate whether placebo effect induced by pharmacological conditioning with intranasal insulin can affect glucose, insulin, C-peptide, hunger, and memory in patients with diabetes type 2 and healthy controls.MethodsPlacebo effect was induced by pharmacological conditioning. Thirty-two older patients (mean age = 68.3 years) with diabetes type 2 and age- and sex-matched thirty-two healthy older adults (mean age = 67.8 years) were randomly assigned to a conditioned or a control group. On day 1, conditioned group received six administrations of intranasal insulin with a conditioned stimulus (CS; smell of rosewood oil), whereas the control group received a placebo with the CS. On day 2, both groups received a placebo spray with the CS. Glucose, insulin, and C-peptide were repeatedly measured in blood. Hunger and memory were assessed with validated measures.ResultsIntranasal insulin stabilized dropping glucose levels in patients (B = 0.03, SE = 0.02, p = .027) and healthy men (B = 0.046, SE = 0.02, p = .021), and decreased C-peptide levels in healthy controls (B = 0.01, SE = 0.001, p = .008). Conditioning also prevented the drop of glucose levels but only in men (both healthy and patients; B = 0.001, SE = 0.0003, p = .024). Conditioning significantly decreased hunger in healthy participants (B = 0.31, SE = 0.09, p < .001). No effects were found on other measures.ConclusionsPlacebo effect induced by conditioning with intranasal insulin modifies blood glucose levels and decreases hunger in older adults, but its effects depend on health status and sex. Insulin conditioning might be beneficial for groups suffering from intensive hunger but seems not be particularly suitable for blood glucose reduction. Show less
Objectives:The current paper explores the psychological predictors of nocebo hyperalgesia and whether the reduction of nocebo hyperalgesia can be predicted by susceptibility to nocebo hyperalgesia... Show moreObjectives:The current paper explores the psychological predictors of nocebo hyperalgesia and whether the reduction of nocebo hyperalgesia can be predicted by susceptibility to nocebo hyperalgesia and psychological characteristics. Methods:Nocebo effects on pressure pain were first experimentally induced in 83 healthy female participants through conditioning with open-label instructions about the pain-worsening function of a sham TENS device to assess susceptibility to nocebo hyperalgesia. Participants were then randomized to 1 out of 2 nocebo-reduction conditions (counterconditioning/extinction) or to continued nocebo-conditioning (control), each combined with open-label instructions about the new sham device function. Dispositional optimism, trait and state anxiety, pain catastrophizing, fear of pain, and body vigilance were assessed at baseline. Results:The results showed that lower optimism and higher trait anxiety were related to a stronger induction of nocebo hyperalgesia. Moreover, a stronger induction of nocebo hyperalgesia and higher trait anxiety predicted a larger nocebo reduction across interventions. Also, nocebo hyperalgesia and optimism moderated the effects of the nocebo-reduction interventions, whereby larger nocebo hyperalgesia and lower optimism were associated with a larger nocebo reduction after counterconditioning, compared with control, and also extinction for larger nocebo hyperalgesia. Discussion:Our findings suggest that open-label conditioning leads to stronger nocebo hyperalgesia when trait anxiety is high and dispositional optimism is low, while these psychological characteristics, along with larger nocebo hyperalgesia, also predict open-label counterconditioning to be an effective nocebo-reduction strategy. Susceptibility to nocebo hyperalgesia, trait anxiety, and dispositional optimism might be indicators of a flexible pain regulatory system. Show less
Karacaoglu, M.; Meijer, S.; Peerdeman, K.J.; Dusseldorp, E.M.L.; Veldhuijzen, D.S.; Middendorp, H. van; Evers, A.W.M. 2023
BackgroundNocebo effects can adversely affect the experience of physical symptoms, such as pain and itch. Nocebo effects on itch and pain have shown to be induced by conditioning with thermal heat... Show moreBackgroundNocebo effects can adversely affect the experience of physical symptoms, such as pain and itch. Nocebo effects on itch and pain have shown to be induced by conditioning with thermal heat stimuli and reduced by counterconditioning. However, open-label counterconditioning, in which participants are informed about the placebo content of the treatment, has not been investigated, while this can be highly relevant for clinical practice. Furthermore, (open-label) conditioning and counterconditioning has not been investigated for pain modalities relevant to musculoskeletal disorders, such as pressure pain. MethodsIn a randomized controlled trial, we investigated in 110 healthy female participants whether nocebo effects on pressure pain combined with open-label verbal suggestions can be (1) induced via conditioning and (2) reduced via counterconditioning. Participants were allocated to either a nocebo- or sham-conditioning group. Next, the nocebo group was allocated to either counterconditioning, extinction or continued nocebo conditioning; sham conditioning was followed by placebo conditioning. ResultsNocebo effects were significantly larger after nocebo conditioning than sham conditioning (d = 1.27). Subsequently, a larger reduction of the nocebo effect was found after counterconditioning than after extinction (d = 1.02) and continued nocebo conditioning (d = 1.66), with effects similar to placebo conditioning (following sham conditioning). ConclusionsThese results show that (counter)conditioning combined with open-label suggestions can modulate nocebo effects on pressure pain, which provides promise in designing learning-based treatments to reduce nocebo effects in patients with chronic pain disorders, particularly for musculoskeletal disorders. SignificanceFew studies have investigated the efficacy counterconditioning to reduce nocebo effects. Whereas typically deceptive procedures are used, these are not ethically appropriate for use in clinical practice. The current study demonstrates that open-label counterconditioning in a pain modality relevant for many chronic pain conditions may be a promising new strategy for reducing nocebo effects in a non-deceptive and ethical manner, which provides promise in designing learning-based treatments to reduce nocebo effects in patients with chronic pain disorders. Show less
AimsImplicit gender biases (IGBs) are unconscious evaluations about a person based on gender. IGBs of healthcare providers may affect medical decision making. This study investigated whether IGBs... Show moreAimsImplicit gender biases (IGBs) are unconscious evaluations about a person based on gender. IGBs of healthcare providers may affect medical decision making. This study investigated whether IGBs and genders of patients and general practitioners (GPs) influence diagnostics and treatment decisions in the context of diabetes type 2.MethodsNinety-nine GPs participated in this randomized online study. Implicit Associations Tasks were used to measure two IGBs, related to lifestyle (women have a healthier lifestyle than men) and communication (men are less communicative than women). Clinical decisions regarding type 2 diabetes were measured with vignettes that included a fictional male or female patient case.ResultsFemale GPs exhibited a significant lifestyle IGB (p < 0.001). GPs of both genders exhibited a significant communication IGB (p < 0.001). Several associations between IGBs and clinical decisions were found. The gender of the vignette character affected several outcomes, for example GPs were less certain in the diabetes diagnosis when the character was a woman (p < 0.001).ConclusionWe demonstrated that GPs have IGBs and these biases as well as patient's gender affect decisions of GP's when they are solving a diabetes vignette case. Future research is needed to understand the most important consequences of IGBs in the context of type 2 diabetes. Show less
Learning and negative outcome expectations can increase pain sensitivity, a phenomenon known as nocebo hyperalgesia. Here, we examined how a targeted pharmacological manipulation of learning would... Show moreLearning and negative outcome expectations can increase pain sensitivity, a phenomenon known as nocebo hyperalgesia. Here, we examined how a targeted pharmacological manipulation of learning would impact nocebo responses and their brain correlates. Participants received either a placebo (n = 27) or a single 80 mg dose of d-cycloserine (a partial NMDA receptor agonist; n = 23) and underwent fMRI. Behavioral conditioning and negative suggestions were used to induce nocebo responses. Participants underwent pre-conditioning outside the scanner. During scanning, we first delivered baseline pain stimulations, followed by nocebo acquisition and extinction phases. During acquisition, high intensity thermal pain was paired with supposed activation of sham electrical stimuli (nocebo trials), whereas moderate pain was administered with inactive electrical stimulation (control trials). Nocebo hyperalgesia was induced in both groups (p < 0.001). Nocebo magnitudes and brain activations did not show significant differences between d-cycloserine and placebo. In acquisition and extinction, there were significantly increased activations bilaterally in the amygdala, ACC, and insula, during nocebo compared to control trials. Nocebo acquisition trials also showed increased vlPFC activation. Increased opercular activation differentiated nocebo-augmented pain aggravation from baseline pain. These results support the involvement of integrative cognitive-emotional processes in nocebo hyperalgesia. Show less
Background: We investigated whether COVID-19 leads to persistent impaired pulmonary function, fibrotic -like abnormalities or psychological symptoms 12 months after discharge and whether severely... Show moreBackground: We investigated whether COVID-19 leads to persistent impaired pulmonary function, fibrotic -like abnormalities or psychological symptoms 12 months after discharge and whether severely ill patients (ICU admission) recover differently than moderately ill patients. Methods: This single-centre cohort study followed adult COVID-19 survivors for a period of one year after dis-charge. Patients underwent pulmonary function tests 6 weeks, 3 months and 12 months after discharge and were psychologically evaluated at 6 weeks and 12 months. Computed tomography (CT) was performed after 3 months and 12 months. Results: 66 patients were analysed, their median age was 60.5 (IQR: 54-69) years, 46 (70%) patients were male. 38 (58%) patients had moderate disease and 28 (42%) patients had severe disease. Most patients had spirometric values within normal range after 12 months of follow-up. 12 (23%) patients still had an impaired lung diffusion after 12 months. Impaired pulmonary diffusion capacity was associated with residual CT abnormalities (OR 5.1,CI-95: 1.2-22.2), shortness of breath (OR 7.0, CI-95: 1.6-29.7) and with functional lim-itations (OR 5.8, CI-95: 1.4-23.8). Ground-glass opacities resolved in most patients during follow-up. Resorp-tion of reticulation, bronchiectasis and curvilinear bands was rare and independent of disease severity. 81% of severely ill patients and 37% of moderately ill patients showed residual abnormalities after 12 months (OR 8.1, CI-95: 2.5-26.4). A minority of patients had symptoms of post-traumatic stress disorder, anxiety, depres-sion and cognitive failure during follow-up. Conclusion: Some patients still had impaired lung diffusion 12 months after discharge and fibrotic-like resid-ual abnormalities were notably prevalent, especially in severely ill patients. (c) 2022 The Authors. Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) Show less
Becker, J.M.; Holle, H.; Ryckeghem, D.M.L. van; Damme, S. van; Crombez, G.; Veldhuijzen, D.S.; ... ; Laarhoven, A.I.M. van 2022
