New insights into the placebo and nocebo responses

A narrative review of the placebo effect: historical roots, current applications, and emerging insights

PURPOSE

Placebo is a term to define physiologically inactive compounds used in treatment that causes physical and emotional changes. The placebo effect, driven by expectation and conditioning, plays a significant role in various conditions like pain, depression, and Parkinson's disease, while the nocebo effect can hinder treatment outcomes. Understanding mechanisms such as neuromodulation and genetics has gained importance in modern medicine. This review aims to explore the clinical relevance of placebo responses, particularly in neuropsychiatric disorders, and their potential in personalized medicine. By integrating placebo research into healthcare, it highlights opportunities to enhance treatment efficacy, improve patient well-being, and reduce reliance on pharmacological interventions.

METHODS

A comprehensive literature search was conducted in PubMed, Scopus, and Google Scholar databases. Recent studies were reviewed to evaluate placebo effects, and the variability of the placebo response in neuropsychiatric disorders was summarized.

RESULTS

Placebo effects significantly impact treatment outcomes across various conditions, including Parkinson's disease, depression, pain syndromes, and epilepsy. The mechanisms involve neurobiological and psychological factors, with evidence suggesting that placebo interventions can modulate neurotransmitter activity and improve patient well-being.

CONCLUSION

Integrating placebo research into clinical practice may enhance treatment outcomes, reduce drug dependency, and support personalized medicine by tailoring interventions to individual placebo responsiveness. Understanding placebo and nocebo mechanisms can optimize therapeutic strategies while minimizing unnecessary pharmacological treatments.

Is It All in Your Head? Placebo Effects in Concussion Prevention

Sports-related concussions (SRCs) are a major health issue in athletes of varying ages, ability levels, and sports. Concerns over the short- and long-term consequences of SRCs have incentivized a wealth of products and policies aimed at reducing SRC risk. Research suggesting the effectiveness of such interventions at reducing SRCs has facilitated their adoption by sports organizations and, in some cases, product commercialization. However, the body of SRC mitigation research is almost entirely devoid of placebo or sham groups, which raises important questions about the true clinical effectiveness of these interventions. This Current Opinion explores the plausibility of placebo effects within the scope of SRC prevention, describes why the lack of placebo/sham groups in the current body of literature is problematic, and provides recommendations for including placebo/sham groups in future SRC research.

The prediction of the analgesic placebo response is moderated by outward-focused attention: A sham, randomized clinical trial of chronic back pain patients

The within-subject variability (WSV) of pain-intensity reports has gained attention as a predictor of the placebo response but has demonstrated mixed results. We hypothesized that participants' inward- and outward-directed attention will moderate WSV's prediction of the analgesic placebo response. In this sham randomized clinical trial (protocol number NCT05994118); placebo response was induced in chronic back-pain patients (n=113) through a saline injection plus verbal suggestion. The WSV assessed by the focused analgesia selection test (FAST) served as a predictor. The revised Self-Consciousness Scale (SCS-R), evaluating a person's tendency to focus attention inward or outward was used to moderate the prediction. The placebo response prediction was significantly moderated by 2 SCS-R subscales: public self-consciousness (b = 46.36, SE = 23.08, t = 2.0, p = 0.047) and social anxiety (b = 44.01, SE = 18.02, t = 2.44, p = 0.016). The prediction was significant at low levels of both moderators (p < 0.01), but not at high levels of these traits. Prediction of the placebo response is of value and could promote personalized medical care. Better understanding of factors shaping the placebo response could further contribute to both clinical practice and clinical trials. PERSPECTIVE: The current study demonstrates that the prediction of the analgesic placebo response could be improved if relevant personal characteristics are included as moderators of the prediction. Better predictions of the placebo response could contribute to improve both clinical research and clinical care.

Placebo Effects: Neurological Mechanisms Inducing Physiological, Organic, and Belief Responses-A Prospective Analysis

The placebo effect can induce physiological or clinical neurological and organic responses despite the recipient receiving no active ingredients; these responses are based instead on the recipient's perceptions. Placebo effects come from the rostral anterior cingulate cortex, pontine nucleus, and cerebellum of the brain; this information provides a better understanding of placebo effects and can also help us understand the mechanism of the modulation of neurotransmitters from the use of psychedelic substances, activity of selective serotonin reuptake inhibitors, the process of transcranial magnetic stimulation, and deep brain stimulation, as well as aid in developing novel therapies, challenging the validity of controlled clinical trials (RCTs) that the regulatory agencies now appreciate. Education about how placebo effects bring in social, political, and religious beliefs and whether these can be modulated may help reduce global confrontations.

The expectations humans have of a pleasurable sensation asymmetrically shape neuronal responses and subjective experiences to hot sauce

Expectations shape our perception, profoundly influencing how we interpret the world. Positive expectations about sensory stimuli can alleviate distress and reduce pain (e.g., placebo effect), while negative expectations may heighten anxiety and exacerbate pain (e.g., nocebo effect). To investigate the impact of the (an)hedonic aspect of expectations on subjective experiences, we measured neurobehavioral responses to the taste of hot sauce among participants with heterogeneous taste preferences. By identifying participants who "liked" versus those who strongly "disliked" spicy flavors and by providing contextual cues about the spiciness of the sauce to be tasted, we dissociated the effects of positive and negative expectations from sensory stimuli (i.e., visual and gustatory stimuli), which were the same across all participants. Our results indicate that positive expectations lead to modulations in the intensity of subjective experience. These modulations were accompanied by increased activity in brain regions previously linked to information integration and the placebo effect, including the anterior insula, dorsolateral prefrontal cortex, and dorsal anterior cingulate cortex, as well as a predefined "pleasure signature." In contrast, negative expectations decreased hedonic experience and increased neural activity in the previously validated "Neurological Pain Signature" network. These findings demonstrate that hedonic aspects of one's expectations asymmetrically shape how the brain processes sensory input and associated behavioral reports of one's subjective experiences of intensity, pleasure, and pain. Our results suggest a dissociable impact of hedonic information: positive expectations facilitate higher-level information integration and reward processing, while negative expectations prime lower-level nociceptive and affective processes. This study demonstrates the powerful role of hedonic expectations in shaping subjective reality and suggests potential avenues for consumer and therapeutic interventions targeting expectation-driven neural processes.

The Nocebo Effect: A Bias in Clinical Practice-An Ethical Approach

BACKGROUND

The nocebo effect is often disregarded in medical practice and is certainly much less known than the placebo effect, although, in reality, both can influence therapeutic decision making and the quality of life of patients. However, the nocebo effect raises a number of issues not only of a practical nature related to clinical activity but also ethical dilemmas related to the observance of the patient's autonomy, nonmaleficence, or informed consent and the information on which it is based.

AREAS OF UNCERTAINTY

The ethical dilemmas raised by the nocebo effect revolve around how informed consent can be achieved, the accuracy and volume of information that is transmitted to the patient, and how to report negative side effects of therapeutic treatment.

DATA SOURCES

In September 2023, a narrative analysis of the literature was conducted using a combination of keywords such as nocebo, placebo, ethics, therapeutic relationship from PubMed, Scopus, Google Scholar, and so on, as well as from official documents developed at an international level (World Health Organization), for a period of 10 years (2012-2021).

RESULTS

Analyzing the articles that remarked upon the significant impact of ethics in nocebo research or in the therapeutic relationship, we can state that the existence of several relevant issues of interest have been detected regarding the ethical use of nocebo and its impact in research or in clinics and thus the need for proper knowledge and management of the impact of nocebo effects. The ethical paradox of obtaining informed consent with the 2 goals, first, the need for complete information and second, the preservation of the autonomy of the patient, respectively, that of "primum non-nocere" and of avoiding unnecessary harm by revealing probable adverse effects is a point of interest for numerous studies. The potential for a nocebo effect is present when we inform patients about the risks and benefits of treatment, there being a clear link between the moral and ethical duty to inform patients and the need to avoid situations that increase the nocebo impact on how the disease or the adverse effects of the treatment are perceived. Adapting information about the side effects of medicines should focus on ensuring a balance between transparency and caution, especially in patients with a high potential for nocebo effect.

CONCLUSIONS

The nocebo effect had for a long time been unknown or denied, although it can interfere with the results of the treatment used. As the nocebo phenomenon becomes increasingly known in medical practice, the clinical and ethical implications are identified by medical staff, and nocebo's adverse responses are no longer ignored.

Psychodynamically Informed Brain Stimulation: Building a Bridge from Brain to Mind

Since its inception, psychiatry has undergone several periods of radical identity transformation. Initially limited to psychotherapy alone, the advent of medications stimulated an era of biological psychiatry. For years, medications served as the mainstay of biological treatments, paralleled by a rise in treatment resistance. Brain stimulation therapies are psychiatry's newest arm of intervention and represent an area ripe for exploration. These techniques offer new hope to treatment-resistant patients, but in a manner often dissociated from psychoanalytic conceptualization and the practice of psychotherapy. There is growing interest in bridging this divide. In this article, we continue the efforts at interweaving what may seem to be disparate approaches through the topic of treatment resistance. This article aims to engage interventional psychiatrists in considering psychosocial dimensions of their treatments and to provide education for psychoanalytic clinicians on the history, mechanism of action, and applications of brain stimulation technologies.

Nocebo expectations rather than placebo expectations affect topical pain relief: A randomized clinical trial

Patients' expectations and beliefs regarding the potential benefits and harms of medical interventions may induce placebo and nocebo effects, and affect the response to pain therapies. In a randomized clinical trial, we examined the effect of placebo and nocebo expectations on pain relief and adverse events (AEs) in association with a topical treatment among 65 cancer survivors experiencing chronic musculoskeletal pain. Participants received either a 1% camphor-based topical pain patch or a placebo treatment for 14 days. We measured pain severity with the worst pain item of the Brief Pain Inventory (BPI) at baseline and 14 days and treatment expectations at baseline with validated expectation questionnaires. We found that high vs. low nocebo expectations decreased pain severity improvements by 2.5 points (95% confidence interval [CI] -3.8 to -1.2; p<0.001) on a 0-10 numeric rating scale of the BPI and pain response rate by 42.7% (95% CI 0.2-0.6; p<0.001) at day 14, irrespective of placebo expectation status or treatment arms. Patients with high vs. low nocebo expectations in the true arm reported 22.4% more unwanted AEs. High nocebo expectations were associated with increased AEs by 39.5% (odds ratio: 12.0, 95% CI 1.2, 145.5; p=0.029) and decreased pain response in the true arm vs. placebo. Our study demonstrated that nocebo expectations, rather than placebo expectations, elevate the risk of AEs and compromise the effect of topical pain interventions. The findings raise the possibility that nocebo expectations may worsen somatic symptoms through heightening central pain amplification and should be further investigated.

Exploratory study of nocebo effect in senior medical students

Background

Νocebo Effect is known to induce adverse symptoms after negative expectations which can be manifested on a physical and psychological level. As 6th year medical students often face a wide range of clinical challenges and may be prone to negative expectations or beliefs affecting their pre-clinical and clinical success, we want to investigate how they are affected by the Nocebo Effect.

Objective

To investigate whether a nocebo effect can be induced when exposing final-year students to the clinical context of their training.

Methods

We used verbal suggestions as a nocebo mechanism and by using three tools, the Illness Attitude Scales, the Symptom Checklist-90, and the State-Trait Anxiety Inventory, we examined the difference in scores on measures of psychometric parameters in 33 participants who were on their 6th year medical and attended three clinics for the first time during their education. The administrations were given before and after attending each clinic, and negative verbal suggestions were given prior to the first administration. We also measured whether the overall number of clinics, had an effect on psychometric parameters.

Results

The results revealed a significant increase in second administration overall in the three clinics in specific psychometric parameters but no statistically significant difference was observed after attending consecutive clinics.

Conclusion

Students reported the occurrence of adverse symptoms in the investigated psychometric parameters, which should be noted in order to avoid potential educational clinical failure.

Open-label placebos enhance test performance and reduce anxiety in learner drivers: a randomized controlled trial

Passing the driving school test can be very challenging, especially in big cities, where up to 52% of all students fail this test. Consequently, many learner drivers experience stress and anxiety. For some learner drivers these feelings can be extreme and negatively affect the performance in the driving test. Different strategies to face anxiety and stress are known, including, for example, psychological or pharmacological approaches and even placebo pills. Recent intriguing findings have also demonstrated that placebos without deception, so-called open-label placebos, successfully reduce anxiety. Here we aimed to test effects of this novel treatment for learner drivers. We investigated whether open-label placebos affect test performance and feelings of anxiety in learner drivers. Sixty-eight healthy participants (mean age 21.94 years, 26 females) were randomized into two groups. The open-label placebo group received placebo pills two weeks before the driving test (two pills each day). The control group received no treatment. Results revealed that the open-label placebo group experienced significantly less anxiety than the control group before the test (measured with the State-Trait-Anxiety-Inventory, STAI-S, and the German Test Anxiety Inventory, PAF). Moreover, in the open-label placebo group less learner drivers failed the driving test (29.41% vs. 52.95%). The results suggest that open-label placebos may provide an ethical unproblematic way to experience less anxiety and might also enhance the probability to pass the driving test. We discuss possible mechanisms of open-label placebos and limitations of our findings.

Placebo and Nocebo Responses in Pharmacological Trials of Tic Disorders: A Meta-Analysis

BACKGROUND

Clinical trials of new drugs for tic disorders (TD) often fail to yield positive results. Placebo and nocebo responses play a vital role in interpreting the outcomes of randomized controlled trials (RCTs), yet these responses in RCTs of TD remain unexplored.

OBJECTIVE

The aim was to assess the magnitude of placebo and nocebo responses in RCTs of pharmacological interventions for TD and identify influencing factors.

METHODS

A systematic search of the Embase, Medline, Cochrane Central Register of Controlled Trials, and PsycINFO databases was conducted. Eligible studies were RCTs that compared active pharmacological agents with placebos. Placebo response was defined as the change from baseline in TD symptom severity in the placebo group, and nocebo response as the proportion experiencing adverse events (AEs) in this group. Subgroup analysis and meta-regression were performed to explore modifying factors.

RESULTS

Twenty-four trials involving 2222 participants were included in this study. A substantial placebo response in TD symptom severity was identified, with a pooled effect size of -0.79 (95% confidence interval [CI] -0.99 to -0.59; I2 = 67%). Forty-four percent (95% CI 27% to 63%; I2 = 92%) of patients experienced AEs while taking inert pills. Sample size, study design, and randomization ratio were correlated with changes in placebo and nocebo responses.

CONCLUSION

There were considerable placebo and nocebo responses in TD clinical trials. These results are of great relevance for the design of future trials and for clinical practice in TD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration ID CRD42023388397. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Placebo and nocebo in the treatment of migraine: How much does real world effectiveness depend on contextual effects?

PURPOSE

Treatments in medicine impact individuals beyond their intended effects, due to phenomena such as the placebo and nocebo effects. The placebo effect arises from the positive expectation of a treatment being beneficial, while the nocebo effect stems from the negative expectation of a treatment causing harm. Both in real-world practice and clinical trials, treatments can lead to outcomes unrelated to their intended mechanism of action, which we categorize as placebo and nocebo responses. These responses, combined with the inherent fluctuation in a condition's natural progression, regression to the mean, and random comorbidities, make up a significant part of the therapeutic experience. Particularly in pain management, placebo and nocebo effects play a substantial role. By addressing modifiable contextual factors such as patient expectations, lifestyle choices, and the therapeutic relationship, healthcare providers can enhance the effectiveness of migraine treatments, paving the way for a more comprehensive, individualized approach to patient care. We must also consider non-modifiable factors like personal experiences, beliefs, and information from social media and the internet.

CONCLUSION

This review offers a summary of our current understanding of the placebo and nocebo effects in migraine management.

Role of expectations in clinical outcomes after deep brain stimulation in patients with Parkinson's disease: a systematic review

Deep brain stimulation (DBS) is a well-established treatment that significantly improves the motor symptoms of patients with Parkinson's disease (PD); however, patients may experience post-operative psychological distress and social maladjustments. This phenomenon has been shown to be related to patients' pre-operative cognitive representations, such as expectations. In this systematic review, we discuss the findings on the role of the expectations of patients with PD regarding the clinical outcomes of DBS to identify areas of intervention to improve pre-operative patient education and promote successful post-operative psychosocial adjustment. PubMed was searched for relevant articles published up to 16 January 2023. Of the 84 identified records, 10 articles focusing on the treatment expectations of patients with PD undergoing DBS were included in this review. The selected studies were conducted among cohorts of patients with different DBS targets, among which the most common was the bilateral subthalamic nucleus. Overall, the data showed that patients' expectations contribute to treatment efficacy. Experiments investigating the placebo effect itself have shown clinical improvement after the induction of positive therapeutic expectations; conversely, unrealistic treatment expectations can affect patient satisfaction after surgery, clinical outcomes, and subjective well-being. This review highlights the need for routine clinical practice to better investigate and manage patients' pre-operative expectations, as well as multidisciplinary education to improve patient satisfaction and psychosocial adjustment after DBS.

How Do Expectations Modulate Pain? A Motivational Perspective

Expectations can profoundly modulate pain experience, during which the periaqueductal gray (PAG) plays a pivotal role. In this article, we focus on motivationally evoked neural activations in cortical and brainstem regions both before and during stimulus administration, as has been demonstrated by experimental studies on pain-modulatory effects of expectations, in the hope of unraveling how the PAG is involved in descending and ascending nociceptive processes. This motivational perspective on expectancy effects on the perception of noxious stimuli sheds new light on psychological and neuronal substrates of pain and its modulation, thus having important research and clinical implications.

Can open label placebos improve pain and gluten tolerance via open label placebos in fibromyalgia patients? A study protocol for a randomised clinical trial in an outpatient centre

INTRODUCTION

Fibromyalgia syndrome (FMS) is defined as a medical condition with chronic widespread musculoskeletal pain accompanied by mood disorders, fatigue and sleep disturbances. Treatment of this condition can often be challenging. As nutrition in general and nutritional interventions in the context of illness management become more and more important, current research also focuses on the relevance of diets for FMS, including gluten as field of interest. To date, there is no clear evidence that a gluten-free diet or other nutritional interventions are significantly important for the reduction of pain in the context of FMS. Only a very few studies show that FMS patients respond to a gluten-free diet and that cytokine production (also in FMS) can be reduced through the change. However, these studies have not investigated whether and to what extent cognitive factors, such as the expectation of symptom reduction triggered by diet, play a role. Recent research shows that treatment expectation plays an important role in the course of the disease and in the effectiveness of treatment approaches. For example, there are promising pain treatment options using open-label placebos (OLPs), which show that expectation alone, rather than the pharmacological substance of medication, can reduce pain experience. In our study protocol, we hypothesise that treatment expectation can be positively influenced by the given information regarding the placebos, resulting in improved treatment outcomes for pain and indigestions.

METHODS AND ANALYSIS

In this trial, patients with FMS will undergo a food challenge and take an OLP (patients will be informed about the placebo), followed by a 3-week OLP treatment. The subjects will be randomised into four groups: (a) gluten-free porridge+neutral OLP instructions; (b) gluten-free porridge+positive OLP instructions; (c) gluten-containing porridge+neutral OLP instructions and (d) gluten-containing porridge+positive OLP instructions. Patients will be recruited via different institutions and support groups in Hamburg. The inclusion criteria are (a) diagnosed FMS, (b) absence of wheat allergy, coeliac disease or pain-related red flags and (c) being a minimum age of 18 years. The study requires 100 subjects to assess the primary outcomes: pain intensity and occurence of indigestion. Secondary outcomes are functional capacity, treatment expectation, and different pain-related and inflammation-related blood parameters. The measure time points will be before and after the food challenge and before and after the 3-week OLP treatment.

ETHICS AND DISSEMINATION

Ethical approval was obtained in October 2021 from the Hamburg Medical Ethics Council. The results of the study will be disseminated through publications, presentations and conference meetings.

TRIAL REGISTRATION NUMBER

German Clinical Trials Register (DRKS; DRKS00027130).

Quality of life in the adjuvant setting: A meta-analysis of US Food and Drug Administration approved anti-cancer drugs from 2018 to 2022

BACKGROUND

In oncology, quality of life (QoL) questionnaires were historically designed to be used in the advanced or metastatic setting. We sought to determine the effects of contemporary treatments on QoL in the adjuvant setting and to determine if the QoL instruments used in these studies provide a relevant assessment.

METHODS

We conducted a systematic identification of all anti-cancer drugs used in the adjuvant setting and approved by the US Food and Drug Administration from January 2018 to March 2022. We conducted a quality evaluation and a meta-analysis of reported QoL results. We used the global QoL results when multiple QoL outcomes were reported.

RESULTS

There were 224 FDA approvals reviewed, of which 12 met the inclusion criteria. The placebo was the control arm in 10 out of 12 trials. Of those, 11 trials (92 %) assessed QoL, and ten (83 %) reported results. In reports with QoL results, a moderate-risk of bias was found in 3 out of 10 (30 %) and a high-risk of bias in 6 out of 10 (60 %) of reports, respectively. No trial reported a meaningful difference between arms. The meta-analysis found an overall detrimental effect on QoL in the experimental arm, though it was not statistically different.

CONCLUSION

This study identified 12 FDA registration trials in the adjuvant setting between 2018 and 2022. We found a moderate- to high-risk of bias in 90 % of the ten trials reporting QoL data. Our meta-analysis suggested a detrimental effect on QoL in the experimental arm, questioning the relevancy, in the adjuvant setting, of thresholds that were mostly developed in the advanced or metastatic setting.

POLICY SUMMARY

Future works should focus on specificities of the adjuvant setting when considering QoL evaluation.

Comorbid alcohol use disorder and posttraumatic stress disorder: A proof-of-concept randomized placebo-controlled trial of buprenorphine and naltrexone combination treatment

BACKGROUND

Effective pharmacologic treatments for comorbid alcohol use disorder (AUD) and posttraumatic stress disorder (PTSD) are lacking. Kappa (κ) opioid receptor antagonists may address this unmet need. Buprenorphine is a κ-opioid antagonist and a partial agonist of mu (μ) opioid receptors. Whereas naltrexone blocks all μ-mediated effects combining it with buprenorphine yields a pharmacologic net effect of opioid receptor antagonism. Because no κ-opioid receptor antagonist it available for clinical use, we tested this combination in a proof-of-concept study.

METHODS

Consenting participants were enrolled in a Phase II, multisite, double-blind, randomized, placebo-controlled trial evaluating the effectiveness of sublingual (SL) buprenorphine combined with extended-release (XR) injectable naltrexone for the treatment of comorbid AUD and PTSD. Eligible participants (n = 75) were randomized (1:1:1) to receive either buprenorphine 2 mg/day plus naltrexone-XR (n = 35), buprenorphine 8 mg/day plus naltrexone-XR (n = 6) or SL plus injectable placebo (n = 34) for 12 weeks. The buprenorphine 8 mg/day plus naltrexone-XR arm was dropped early in the trial due to the negative impact of COVID-19 on enrollment. A binary primary outcome of response at week 8 was defined as a decrease from baseline of ≥10 points on the past week Clinician-Administered PTSD Scale (CAPS-5) and a reduction of ≥1 of past month alcohol risk level, as defined by the World Health Organization (WHO) and measured by the Timeline Follow-Back.

RESULTS

Based on the results of a futility analysis, enrollment was stopped prior to reaching the initial goal of 90 participants. At the week eight primary timepoint, there were no statistically significant differences between buprenorphine plus naltrexone-XR and placebo group for the primary composite outcome (OR = 0.63; p-value = 0.52), or the subcomponents of the PTSD outcome (OR = 0.76; p-value = 0.69) and AUD outcome (OR = 0.17; p-value = 0.08). The placebo arm had a significantly higher proportion of participants with ≥1 WHO risk level reduction than the buprenorphine plus naltrexone-XR arm (OR = 0.18, p value = 0.02).

CONCLUSIONS

This is the first study to evaluate the potential of κ-opioid receptor antagonism for the treatment of comorbid AUD and PTSD. The combination of buprenorphine and naltrexone-XR showed no significant improvement over placebo for the composite, PTSD, or alcohol measures.

Impact of comorbidity on symptomatology in various types of environmental intolerance in a general Swedish and Finnish adult population

Comorbidity with various health conditions is common in environmental intolerances (EIs), which restricts understanding for what symptoms that are associated with the intolerance per se. The present objectives were to study (i) prevalence of a broad range of specific symptoms in chemical, building-related, electromagnetic field- (EMF) related, and sound EI, irrespective of comorbidity, (ii) prevalence of symptoms in body systems in exclusive EIs, and (iii) increased risk of symptoms in body systems in exclusive EIs that cannot be referred to functional somatic syndromes, inflammatory diseases or mental disorders. Cross-sectional data (n = 4941) were used from two combined population-based surveys, the Västerbotten (Sweden) and Österbotten (Finland) Environmental Health Studies. Categorization of EI cases and controls were based on self-reports. Symptoms were assessed with the Environmental Hypersensitivity Symptom Inventory, and these were converted to 27 symptoms of the International Classification of Primary Care, 2nd edition, in eight chapters of body systems. The results showed, with few exceptions, that all assessed specific symptoms were significantly more prevalent in all four EIs than in referents. Although a large overlap between EIs, characteristic body system symptoms were eye and respiratory symptoms in chemical and building-related intolerance, skin symptoms in EMF-related intolerance, and general and unspecified, digestive, eye, cardiovascular, neurological, and psychological symptoms in sound intolerance. After controlling for various comorbidities, all studied body system symptoms were positively associated with chemical intolerance, fewer with sound intolerance, only one with building-related intolerance, and none with EMF-related EI. In conclusion, a broad range of symptoms are reported in all four EIs implying common mechanisms, but symptoms of certain body systems are more likely to be reported in a certain EI that cannot be explained by comorbidity.

Placebo effects during the waiting period for psychotherapy in patients with depression

Patients with mental health problems typically have to wait for psychological therapies. This study aimed to investigate the effects of a placebo administered to patients with depression while they were waiting for cognitive-behavioral therapy. Sixty-seven patients were randomly assigned to a three-week waiting period with or without treatment with a take-home placebo for daily usage (herbal medicine to mobilize the body’s natural healing powers to be taken orally). Symptoms of depression (self-rated and clinician-rated) were assessed at the beginning and end of the waiting period. Moreover, each week the patients evaluated levels of energy, concentration, relaxation, well-being, and sleep quality. The placebo group showed a greater reduction in symptoms of depression (self-rated and clinician-rated) compared to the standard group. Moreover, placebo treatment was associated with improved overall well-being during the waiting period. In conclusion, placebo treatment can make the wait time for psychotherapy more tolerable for patients with depression.

Clinical trial registration: German Clinical Trials Register (DRKS00028118)

Pre-surgery optimization of patients' expectations to improve outcome in heart surgery: Study protocol of the randomized controlled multi-center PSY-HEART-II trial

The PSY-HEART-I trial indicated that a brief expectation-focused intervention prior to heart surgery improves disability and quality of life 6 months after coronary artery bypass graft surgery (CABG). However, to investigate the clinical utility of such an intervention, a large multi-center trial is needed to generalize the results and their implications for the health care system. The PSY-HEART-II study aims to examine whether a preoperative psychological intervention targeting patients' expectations (EXPECT) can improve outcomes 6 months after CABG (with or without heart valve replacement). EXPECT will be compared to Standard of Care (SOC) and an intervention providing emotional support without targeting expectations (SUPPORT). In a 3-arm multi-center randomized, controlled, prospective trial (RCT), N = 567 patients scheduled for CABG surgery will be randomized to either SOC alone or SOC and EXPECT or SOC and SUPPORT. Patients will be randomized with a fixed unbalanced ratio of 3:3:1 (EXPECT: SUPPORT: SOC) to compare EXPECT to SOC and EXPECT to SUPPORT. Both psychological interventions consist of 2 in-person sessions (à 50 minute), 2 phone consultations (à 20 minute) during the week prior to surgery, and 1 booster phone consultation post-surgery 6 weeks later. Assessment will occur at baseline approx. 3-10 days before surgery, preoperatively the day before surgery, 4-6 days later, and 6 months after surgery. The study's primary end point will be patients' illness-related disability 6 months after surgery. Secondary outcomes will be patients' expectations, subjective illness beliefs, quality of life, length of hospital stay and blood sample parameters (eg, inflammatory parameters such as IL-6, IL-8, CRP). This large multi-center trial has the potential to corroborate and generalize the promising results of the PSY-HEART-I trial for routine care of cardiac surgery patients, and to stimulate revisions of treatment guidelines in heart surgery.

Manipulating expectancies in optometry practice: Ocular accommodation and stereoacuity are sensitive to placebo and nocebo effects

INTRODUCTION

There is scientific evidence that an individual's beliefs and/or expectations play a role in the behavioural and physiological response to a given treatment. This study aimed to assess whether the dynamics of the accommodative response and stereoacuity are sensitive to experimentally induced placebo and nocebo effects.

METHODS

Nineteen healthy university students performed three experimental sessions (placebo, nocebo and control) in randomised order, with the dynamics of the accommodative response (magnitude and variability), stereoacuity and subjective measures being assessed in all sessions. For the experimental manipulation, participants ingested an inert capsule that was alleged to have positive (white capsule, placebo condition) or negative (yellow capsule, nocebo conditions) effects on the human physiology. In the control condition, participants did not ingest a capsule.

RESULTS

The data revealed that the variability of accommodation was sensitive to experimentally induced placebo and nocebo effects, showing a more stable accommodative response for the placebo compared with the nocebo condition (corrected p-value = 0.04, Cohen's d = 0.60). In addition, better stereoacuity was found with the placebo, compared with the nocebo (corrected p-value = 0.01, Cohen's d = 0.69) and control (corrected p-value = 0.03, Cohen's d = 0.59) conditions. Successful experimental manipulation was confirmed by the analysis of subjective perceptions.

CONCLUSIONS

These findings provide evidence that manipulating expectations about the efficacy of an inert treatment affect the dynamics of the accommodative response (variability of accommodation) and stereoacuity. The results have important applications in both clinical and research outcomes, where individuals´ beliefs/expectations could modulate the visual function.

Optimized Informed Consent for Psychotherapy: Protocol for a Randomized Controlled Trial

Background

Informed consent is a legal and ethical prerequisite for psychotherapy. However, in clinical practice, consistent strategies to obtain informed consent are scarce. Inconsistencies exist regarding the overall validity of informed consent for psychotherapy as well as the disclosure of potential mechanisms and negative effects, the latter posing a moral dilemma between patient autonomy and nonmaleficence.

Objective

This protocol describes a randomized controlled web-based trial aiming to investigate the efficacy of a one-session optimized informed consent consultation.

Methods

The optimized informed consent consultation was developed to provide information on the setting, efficacy, mechanisms, and negative effects via expectation management and shared decision-making techniques. A total of 122 participants with an indication for psychotherapy will be recruited. Participants will take part in a baseline assessment, including a structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders-fifth edition (DSM-5) disorders. Eligible participants will be randomly assigned either to a control group receiving an information brochure about psychotherapy as treatment as usual (n=61) or to an intervention group receiving treatment as usual and the optimized informed consent consultation (n=61). Potential treatment effects will be measured after the treatment via interview and patient self-report and at 2 weeks and 3 months follow-up via web-based questionnaires. Treatment expectation is the primary outcome. Secondary outcomes include the capacity to consent, decisional conflict, autonomous treatment motivation, adherence intention, and side-effect expectations.

Results

This trial received a positive ethics vote by the local ethics committee of the Center for Psychosocial Medicine, University-Medical Center Hamburg-Eppendorf, Hamburg, Germany on April 1, 2021, and was prospectively registered on June 17, 2021. The first participant was enrolled in the study on August 5, 2021. We expect to complete data collection in December 2022. After data analysis within the first quarter of 2023, the results will be submitted for publication in peer-reviewed journals in summer 2023.

Conclusions

If effective, the optimized informed consent consultation might not only constitute an innovative clinical tool to meet the ethical and legal obligations of informed consent but also strengthen the contributing factors of psychotherapy outcome, while minimizing nocebo effects and fostering shared decision-making.

Trial Registration

PsychArchives; http://dx.doi.org/10.23668/psycharchives.4929

International Registered Report Identifier (IRRID)

DERR1-10.2196/39843

Effect of acupuncture on brain regions modulation of mild cognitive impairment: A meta-analysis of functional magnetic resonance imaging studies

Background

As a non-pharmacological therapy, acupuncture has significant efficacy in treating Mild Cognitive Impairment (MCI) compared to pharmacological therapies. In recent years, advances in neuroimaging techniques have provided new perspectives to elucidate the central mechanisms of acupuncture for MCI. Many acupuncture brain imaging studies have found significant improvements in brain function after acupuncture treatment of MCI, but the underlying mechanisms of brain regions modulation are unclear.

Objective

A meta-analysis of functional magnetic resonance imaging studies of MCI patients treated with acupuncture was conducted to summarize the effects of acupuncture on the modulation of MCI brain regions from a neuroimaging perspective.

Methods

Using acupuncture, neuroimaging, magnetic resonance, and Mild Cognitive Impairment as search terms, PubMed, EMBASE, Web of Science, Cochrane Library, Cochrane Database of Systematic Reviews, Cochrane Database of Abstracts of Reviews of Effects (DARE), Google Scholar, China National Knowledge Infrastructure (CNKI), China Biology Medicine disk (CBM disk), Wanfang and Chinese Scientific Journal Database (VIP) for brain imaging studies on acupuncture on MCI published up to April 2022. Voxel-based neuroimaging meta-analysis of fMRI data was performed using voxel-based d Mapping with Permutation of Subject Images (SDM-PSI), allowing for Family-Wise Error Rate (FWER) correction correction for correction multiple comparisons of results. Subgroup analysis was used to compare the differences in brain regions between the acupuncture treatment group and other control groups. Meta-regression was used to explore demographic information and altered cognitive function effects on brain imaging outcomes. Linear models were drawn using MATLAB 2017a, and visual graphs for quality evaluation were produced using R software and RStudio software.

Results

A total of seven studies met the inclusion criteria, with 94 patients in the treatment group and 112 patients in the control group. All studies were analyzed using the regional homogeneity (ReHo) method. The experimental design of fMRI included six task state studies and one resting-state study. The meta-analysis showed that MCI patients had enhanced activity in the right insula, left anterior cingulate/paracingulate gyri, right thalamus, right middle frontal gyrus, right median cingulate/paracingulate gyri, and right middle temporal gyrus brain regions after acupuncture treatment. Further analysis of RCT and longitudinal studies showed that Reho values were significantly elevated in two brain regions, the left anterior cingulate/paracingulate gyrus and the right insula, after acupuncture. The MCI group showed stronger activity in the right supramarginal gyrus after acupuncture treatment compared to healthy controls. Meta-regression analysis showed that the right anterior thalamic projection ReHo index was significantly correlated with the MMSE score after acupuncture treatment in all MCI patients.

Conclusions

Acupuncture therapy has a modulating effect on the brain regions of MCI patients. However, due to the inadequate experimental design of neuroimaging studies, multi-center neuroimaging studies with large samples are needed better to understand the potential neuroimaging mechanisms of acupuncture for MCI. In addition, machine learning algorithm-based predictive models for evaluating the efficacy of acupuncture for MCI may become a focus of future research.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022287826, identifier: CRD 42022287826.

Nocebo Response in Attention Deficit Hyperactivity Disorder: Meta-Analysis and Meta-Regression of 105 Randomized Clinical Trials

OBJECTIVE

To determine nocebo response in ADHD, identify covariates modifying nocebo response, and study the relationship between nocebo response and drug safety.

METHOD

Systematic review of randomized, double-blind, placebo-controlled clinical trials (RCT) investigating the efficacy and safety of pharmacological interventions for ADHD patients. The influence of covariates was studied using meta-regression.

RESULTS

A total of 105 studies with 8,743 patients in placebo arms were included. Slightly over half (55.5%) of the patients experienced adverse events (AE) while receiving placebo. Nocebo response was associated positively with age, treatment length and method for collecting AEs. Studies with the largest nocebo response showcased the greatest drug response and the best outcome for drug safety.

CONCLUSION

Nocebo response in ADHD RCTs is remarkable, showing a positive relationship with drug response, and a negative relationship with drug safety.

Open-label placebos as adjunctive therapy for patients with depression

Background

Placebos prescribed as 'regular' medication can reduce symptoms of depression. However, using a placebo without patients' informed consent presents ethical issues. Therefore, the present study assessed the efficacy of an open-label placebo (OLP), which was administered concurrently with cognitive-behavioral therapy (CBT).

Methods

Sixty patients (mean age: 48 years) diagnosed with major depressive disorder were randomly assigned to a 4-week CBT outpatient program with or without daily OLP treatment. The patients were assessed directly before and after the program as well as three months after the therapy.

Results

Compared to the CBT group, the CBT + OLP group showed a greater reduction in symptoms of depression at the end of the program. Changes in categories pertaining to severity of depression did not differ between groups. All patients completed the program. Noncompliance with the follow-up appointment differed significantly between CBT + OLP (27%) and CBT (7%). Noncompliance was associated with a negative evaluation of the OLP.

Conclusions

The OLP intervention reduced symptoms of depression, however, these changes were not clinically meaningful. The OLP increased the risk for loss to follow-up. The high dropout rate in the present study raises questions concerning the acceptance of OLPs in the treatment of depression.

The ABC Model of Happiness-Neurobiological Aspects of Motivation and Positive Mood, and Their Dynamic Changes through Practice, the Course of Life

Simple Summary

This article proposes a new model for exploring happiness primarily from a neurobiological perspective. Such understanding includes the dynamics of positive mood states and how they change throughout life. Happiness is not a cognitive construct: it is an immediate emotional experience—a feeling that relies on neurophysiological activation in the brain’s reward system. With this in mind, three types of happiness are proposed: (A) wanting, approaching, and pleasure, (B) avoiding, departing, and relief, (C) non-wanting, staying, and satisfaction. Behind this is a sophisticated (neuro)biological dynamic, ranging from the search for autonomy and ecstasy, which is particularly characteristic of young people, to the way we cope with stress, as we find it pronounced in the middle-aged, to deep contentment, peace, and inner joy, as it is mainly attributed to older people. Paradoxically, it is in fact the elderly who appear to be the happiest and most content—this phenomenon is also known as the “satisfaction paradox”. Apparently, these dynamic changes in happiness can be amplified with practice. Happiness is biological in this context, but can still be “learned”. Contemplative practices can serve as an example here to demonstrate this trainability, and they may themselves influence the course of happiness.

Abstract

Background: Happiness is a feeling, an immediate experience, not a cognitive construct. It is based on activity in the brain’s neurobiological reward and motivation systems, which have been retained in evolution. This conceptual review provides an overview of the basic neurobiological principles behind happiness phenomena and proposes a framework for further classification. Results: Three neurobiologically distinct types of happiness exist: (A) wanting, (B) avoiding, and (C) non-wanting. Behind these types lies a dynamic gradation, ranging from the more youthful anticipation, pleasure and ecstasy (A), to stress processing, escape and relief (B) as we find them accentuated in the middle-aged, to deep satisfaction, quiescence and inner joy (C), which is particularly attributed to older people. As a result, the development of happiness and satisfaction over the course of life typically takes the form of a U-curve. Discussion: The outlined triad and dynamic of happiness leads to the paradoxical finding that the elderly seem to be the happiest—a phenomenon that is termed “satisfaction paradox”. This assumed change in happiness and contentment over the life span, which includes an increasing “emancipation” from the idea of good health as a mandatory prerequisite for happiness and contentment, can itself be changed—it is trainable. Conclusions: Programs for mindfulness, contemplation, or stress reduction, including positive psychology and mind–body/behavioral medicine training, seem to be capable of influencing the course happiness over time: Happiness can be shaped through practice.

[Psychosocial factors in pain and pain management : A statement]

Although psychosocial factors have a profound impact on the experience of pain and pain recovery, the transfer to clinical application has so far been insufficient. With this article, a task force of the special interest group "Psychosocial Aspects of Pain" of the German Pain Society (Deutsche Schmerzgesellschaft e. V.) would like to draw attention to the considerable discrepancy between existing scientific evidence on the importance of psychosocial factors in the development of chronic pain disorders and the translation of these findings into the care of pain patients. Our objective is a stronger integration of psychological and psychosomatic expertise in pain treatment and research, as well as the improvement of structural and institutional conditions, to achieve an increased consideration of psychosocial aspects. In this way, modern, integrative and complex pain concepts can reach the patient. Based on these fundamental findings on the importance of psychosocial factors in pain and pain treatment, implications for the transfer to clinic and further research will be shown.

Nocebo Response in the Pharmacological Management of Overactive Bladder: A Systematic Review and Meta-analysis

CONTEXT

The role of a nocebo response in managing urology patients is unclear.

OBJECTIVE

To assess the nocebo response in randomized placebo-controlled overactive bladder (OAB) trials of pharmacological treatment by investigating the adverse events in the placebo arms.

EVIDENCE ACQUISITION

PubMed, Scopus, Embase, and Cochrane Central Register of Controlled Trials were searched to identify potential randomized controlled trials published from 1998 to November 2019. After evaluating the risk of bias in the selected studies, all selected full-text articles were included due to their overall acceptable quality. We extracted the event rate of the most commonly reported adverse events in the placebo arms of OAB trials, and finally, we performed a meta-analysis to calculate the cumulative rate of certain adverse events. The primary outcomes were the event rate of adverse events in the placebo arms of OAB trials of pharmacological treatment, and differences in adverse events in the placebo groups based on drug type and routes of administration.

EVIDENCE SYNTHESIS

After a systematic search and risk of bias assessment, 57 trials comprising 15 446 patients were included in this systematic review. We selected 13 commonly reported adverse events for the meta-analysis. Owing to the possible differences in study samples and design, we used a random model for the analysis. The average age of the patients was 59.5 yr and 79.8% were female. Dry mouth was the most commonly evaluated adverse event reported in 57 studies comprising 15 324 patients; the mean event rate was 4.9% (95% confidence interval [CI] 0.042-0.057, p < 0.001). Constipation was the second most commonly reported adverse event in 49 studies comprising 14 556 patients; the mean event rate of constipation was 2.6% (95% CI 0.022-0.031, p < 0.001). The event rate of headache was evaluated in 33 studies comprising 10 202 patients, with a mean event rate of 3.1% (95% CI 0.026-0.037, p < 0.001).

CONCLUSIONS

Dry mouth, constipation, headache, and nasopharyngitis were the most prevalent events in the included studies. The nocebo response plays a statistically significant role in causing and/or facilitating adverse events. Health care providers should have a better understanding of the positive and negative expectations associated with therapies to achieve the best possible outcomes for each individual patient. Finally, identification of the real effect of nocebo requires studies that also include a no-treatment arm. Research could help us better understand and potentially modify the nocebo response.

PATIENT SUMMARY

In this meta-analysis of 57 studies comprising 15 446 patients, we reviewed the adverse events extracted from the placebo arms of randomized controlled trials studying therapies for overactive bladder. Dry mouth, constipation, headache, and urinary tract infection were the most common adverse events. Adverse events varied based on the drug type and the route of administration. Negative expectations from the therapy and giving verbal information to the patient can cause/alleviate adverse events.

The Nocebo Effect: A Review of Contemporary Experimental Research

BACKGROUND

Nocebo effect, the occurrence of adverse symptoms fallowing an inactive treatment, is much less understood than its opposite, placebo effect. This systematic review of contemporary studies exploring the nocebo effect focuses on (1) the mechanisms underlying the nocebo effect, (2) the characteristics of participants exhibiting a more intensive nocebo response, and (3) the circumstances that might reduce or prevent the nocebo effect.

METHOD

We included experimental nocebo studies published in English that examined the occurrence of nocebo in various domains (i.e., types of sensations and symptoms) and different levels of nocebo response (e.g., performance, self-assessment) and in different populations of participants (healthy and clinical). Using Web of Science, PsycInfo and PubMed, we identified 25 papers (35 studies) that met our criteria with a total of N = 2614 participants, mostly healthy volunteers.

RESULTS

Nocebo was invoked by manipulating expectations, conditioning or both. A narrative content synthesis was conducted. Nocebo was successfully invoked in a range of domains (e.g., pain, nausea, itch, skin dryness) and levels (sensory, affective, psychological, and behavioral). Various characteristics of the conditioning procedure and participants' emotions, expectations, and dispositions are found to be related to the nocebo response, which sheds insight into the possible mechanisms of the nocebo effect. Strategies successful and unsuccessful in diminishing the nocebo response are identified. Limitations of this review include a small sample of studies.

CONCLUSION

These findings point to the universality of nocebo as well as to the importance of participant characteristics and experimental circumstances in invoking the nocebo effect. Further research should examine the nocebo effect in clinical populations.

The Potential Mechanisms of High-Velocity, Low-Amplitude, Controlled Vertebral Thrusts on Neuroimmune Function: A Narrative Review

The current COVID-19 pandemic has necessitated the need to find healthcare solutions that boost or support immunity. There is some evidence that high-velocity, low-amplitude (HVLA) controlled vertebral thrusts have the potential to modulate immune mediators. However, the mechanisms of the link between HVLA controlled vertebral thrusts and neuroimmune function and the associated potential clinical implications are less clear. This review aims to elucidate the underlying mechanisms that can explain the HVLA controlled vertebral thrust--neuroimmune link and discuss what this link implies for clinical practice and future research needs. A search for relevant articles published up until April 2021 was undertaken. Twenty-three published papers were found that explored the impact of HVLA controlled vertebral thrusts on neuroimmune markers, of which eighteen found a significant effect. These basic science studies show that HVLA controlled vertebral thrust influence the levels of immune mediators in the body, including neuropeptides, inflammatory markers, and endocrine markers. This narravtive review discusses the most likely mechanisms for how HVLA controlled vertebral thrusts could impact these immune markers. The mechanisms are most likely due to the known changes in proprioceptive processing that occur within the central nervous system (CNS), in particular within the prefrontal cortex, following HVLA spinal thrusts. The prefrontal cortex is involved in the regulation of the autonomic nervous system, the hypothalamic-pituitary-adrenal axis and the immune system. Bi-directional neuro-immune interactions are affected by emotional or pain-related stress. Stress-induced sympathetic nervous system activity also alters vertebral motor control. Therefore, there are biologically plausible direct and indirect mechanisms that link HVLA controlled vertebral thrusts to the immune system, suggesting HVLA controlled vertebral thrusts have the potential to modulate immune function. However, it is not yet known whether HVLA controlled vertebral thrusts have a clinically relevant impact on immunity. Further research is needed to explore the clinical impact of HVLA controlled vertebral thrusts on immune function.

Placebo Effects in the Context of Religious Beliefs and Practices: A Resting-State Functional Connectivity Study

Background: Placebos (inert substances or procedures) can positively influence a person’s psychological and physical well-being, which is accompanied by specific changes in brain activity. There are many different types of placebos with different effects on health-related variables. This study investigated placebo effects in the context of religious beliefs and practices. The participants received an inert substance (tap water) along with the verbal suggestion that the water would come from the sanctuary in Lourdes (a major Catholic pilgrimage site with reports of miracle cures). We investigated changes in resting-state functional connectivity (rsFC) in three brain networks (default-mode, salience, cognitive control) associated with the drinking of the placebo water.

Methods: A total of 37 females with the belief that water from the sanctuary in Lourdes has positive effects on their spiritual, emotional, and physical well-being participated in this placebo study with two sessions. The participants drank tap water that was labeled “Lourdes water” (placebo) before a 15-min resting-state scan in one session. In the other (control) session, they received tap water labeled as tap water. The participants rated their affective state (valence, arousal) during the session and were interviewed concerning specific thoughts, feelings, and bodily sensations directly after each of the two sessions.

Results: The placebo reduced rsFC in the frontoparietal cognitive control network and increased rsFC in the salience network (insular-cerebellar connectivity). During the session, the participants rated their affective state as very pleasant and calm. The ratings did not differ between the two conditions. Immediately after the session, the participants reported increased intensity of pleasant bodily sensations (e.g., feelings of warmth, tingling) and feelings (e.g., gratefulness) for the “Lourdes water” condition.

Conclusions: The present findings provide the first evidence that placebos in the context of religious beliefs and practices can change the experience of emotional salience and cognitive control which is accompanied by connectivity changes in the associated brain networks.

Manipulating placebo analgesia and nocebo hyperalgesia by changing brain excitability

Harnessing placebo and nocebo effects has significant implications for research and medical practice. Placebo analgesia and nocebo hyperalgesia, the most well-studied placebo and nocebo effects, are thought to initiate from the dorsal lateral prefrontal cortex (DLPFC) and then trigger the brain's descending pain modulatory system and other pain regulation pathways. Combining repeated transcranial direct current stimulation (tDCS), an expectancy manipulation model, and functional MRI, we investigated the modulatory effects of anodal and cathodal tDCS at the right DLPFC on placebo analgesia and nocebo hyperalgesia using a randomized, double-blind and sham-controlled design. We found that compared with sham tDCS, active tDCS could 1) boost placebo and blunt nocebo effects and 2) modulate brain activity and connectivity associated with placebo analgesia and nocebo hyperalgesia. These results provide a basis for mechanistic manipulation of placebo and nocebo effects and may lead to improved clinical outcomes in medical practice.

Sociability-based fitness approach in Parkinson's disease: Comparison with conventional rehabilitation

BACKGROUND AND PURPOSE

The effect of a sociability-based fitness approach on parkinsonian disability in patients with Parkinson's disease (PD) was assessed.

METHODS

Eighty patients diagnosed with PD were randomly assigned to either the group-based rehabilitation (GBR) group (n = 40) or the individual-based rehabilitation (IBR) group (n = 40). The primary outcome was the difference between the two groups in the mean change from baseline to post-training in the total score on the Unified Parkinson's Disease Rating Scale (UPDRS). The secondary outcomes included the change in mental status and the difference in the mean change from baseline to month 3 and month 6 in the total score on the UPDRS.

RESULTS

The mean (±SD) UPDRS scores were 72.0 ± 21.0 in the GBR group and 72.1 ± 18.6 in the IBR group. The UPDRS scores from baseline to post-training were 22.8 ± 13.5 in the GBR group and 10.9 ± 8.8 in the IBR group (difference 11.8 points; 95% confidence interval [CI] 5.0-18.6; p = 0.001). The difference between the groups from baseline to month 3 (difference 10.06 points; 95% CI 3.3-16.8) and the difference between the groups from baseline to month 6 (difference 11.7 points; 95% CI 4.9-18.5) were also significant (p = 0.004 and p = 0.001, respectively). The scores of cognitive function and depression had not changed significantly.

CONCLUSIONS

Patients receiving GBR demonstrated significant improvements in parkinsonian symptoms, suggesting that the sociability-based fitness can be applied to clinical treatment by sustaining the motivation in PD.

Effects of tDCS on neuroplasticity and inflammatory biomarkers in bipolar depression: Results from a sham-controlled study

OBJECTIVES

We investigated the role of peripheral biomarkers associated with neuroplasticity and immune-inflammatory processes on the effects of transcranial direct current stimulation (tDCS), a safe, affordable, and portable non-invasive neuromodulatory treatment, in bipolar depression.

METHODS

This is an exploratory analysis using a dataset from the sham-controlled study the Bipolar Depression Electrical Treatment Trial (BETTER)(clinicaltrials.govNCT02152878). Participants were 52 adults with type I or II bipolar disorder in a moderate-to-severe depressive episode, randomized to 12 bifrontal active or sham tDCS sessions over a 6-week treatment course. Plasma levels of brain derived neurotrophic factor (BDNF), glial cell derived neurotrophic factor (GDNF), interleukins (IL) 2, 4, 6, 8, 10, 18, 33, 1β, 12p70, 17a, interferon gamma (IFN), tumor necrosis factor alpha (TNF) and its soluble receptors 1 and 2, ST2, and KLOTHO were investigated at baseline and endpoint. We performed analyses unadjusted for multiple testing to evaluate whether baseline biomarkers were predictive for depression improvement and changed during treatment using linear regression models.

RESULTS

A time x group interaction (Cohen's d: -1.16, 95% CI = -1.96 to -0.3, p = .005) was found for IL-8, with greater reductions after active tDCS. Higher baseline IL-6 plasma levels was associated with symptomatic improvement after tDCS (F_(1,43) = 5.43; p = .025). Other associations were not significant.

CONCLUSIONS

Our exploratory findings suggested that IL-6 is a potential predictor of tDCS response and IL-8 might decrease after tDCS; although confirmatory studies are warranted due to the multiplicity of comparisons.

Distinct neural networks subserve placebo analgesia and nocebo hyperalgesia

Neural networks involved in placebo analgesia and nocebo hyperalgesia processes have been widely investigated with neuroimaging methods. However, few studies have directly compared these two processes and it remains unclear whether common or distinct neural circuits are involved. To address this issue, we implemented a coordinate-based meta-analysis and compared neural representations of placebo analgesia (30 studies; 205 foci; 677 subjects) and nocebo hyperalgesia (22 studies; 301 foci; 401 subjects). Contrast analyses confirmed placebo-specific concordance in the right ventral striatum, and nocebo-specific concordance in the dorsal anterior cingulate cortex (dACC), left posterior insula and left parietal operculum during combined pain anticipation and administration stages. Importantly, no overlapping regions were found for these two processes in conjunction analyses, even when the threshold was low. Meta-analytic connectivity modeling (MACM) and resting-state functional connectivity (RSFC) analyses on key regions further confirmed the distinct brain networks underlying placebo analgesia and nocebo hyperalgesia. Together, these findings indicate that the placebo analgesia and nocebo hyperalgesia processes involve distinct neural circuits, which supports the view that the two phenomena may operate via different neuropsychological processes.

Magnetic Resonance Imaging Studies on Acupuncture Therapy in Depression: A Systematic Review

Accumulating studies had been performed using magnetic resonance imaging (MRI) to understand the neural mechanism of acupuncture therapy for depression. However, inconsistencies remain due to differences in research designs and MRI analytical methods. Therefore, we aim to summarize the current MRI research and provide useful information for further research by identifying papers published in English and Chinese about MRI studies on acupuncture for depression up to November 2020. A total of 22 studies met the inclusion criteria, including 810 depression patients and 416 health controls (HCs). The applied designs of these studies are mainly random control trial and pre-post designs. The MRI analytical methods are mainly (fractional) amplitude of low-frequency fluctuation (fALFF/ALFF) and functional connectivity (FC), whereas a small subset of studies used voxel-based morphometry (VBM) and diffusion tensor imaging (DTI). The most consistent functional MRI (fMRI) results showed increased N-acetylaspartate/creatine (NAA/Cr) ratios, increased ALFF in the right precuneus, decreased ALFF in the inferior frontal gyrus (IFG), and increased FC of the anterior cingulate cortex (ACC). In contrast, no significant neurological changes were identified in any of the DTI or VBM studies. However, clear, reliable conclusions cannot be drawn due to the use of different designs, analytical methods, seed points selected, types of depression, acupuncture points, and so on. Improved report specifications, well-designed studies, consistent analytical methods, and larger sample sizes will enable the field to better elucidate the underlying mechanisms of acupuncture in depressed patients.

Neuronal regulation of immunity: why, how and where?

Neuroimmunology is one of the fastest-growing fields in the life sciences, and for good reason; it fills the gap between two principal systems of the organism, the nervous system and the immune system. Although both systems affect each other through bidirectional interactions, we focus here on one direction - the effects of the nervous system on immunity. First, we ask why is it beneficial to allow the nervous system any control over immunity? We evaluate the potential benefits to the immune system that arise by taking advantage of some of the brain's unique features, such as its capacity to integrate and synchronize physiological functions, its predictive capacity and its speed of response. Second, we explore how the brain communicates with the peripheral immune system, with a focus on the endocrine, sympathetic, parasympathetic, sensory and meningeal lymphatic systems. Finally, we examine where in the brain this immune information is processed and regulated. We chart a partial map of brain regions that may be relevant for brain-immune system communication, our goal being to introduce a conceptual framework for formulating new hypotheses to study these interactions.

The subthalamic nucleus and the placebo effect in Parkinson's disease

The study of the placebo effect, or response, is related to the investigation of the psychologic component of different therapeutic rituals. The high rate of placebo responses in Parkinson's disease clinical trials provided the impetus for investigating the underlying mechanisms. Ruling out spontaneous remission and regression to the mean through the appropriate experimental designs, genuine psychologic placebo effects have been identified, in which both patients' expectations of therapeutic benefit and learning processes are involved. Specifically, placebo effects are associated with dopamine release in the striatum and changes in neuronal activity in the subthalamic nucleus, substantia nigra pars reticulata, and motor thalamus in Parkinson's disease, as assessed through positron emission tomography and single-neuron recording during deep brain stimulation, respectively. Conversely, verbal suggestions of clinical worsening or drug dose reduction induce nocebo responses in Parkinson's disease, which have been detected at both behavioral and electrophysiologic level. Important implications and applications emerge from this new knowledge. These include better clinical trial designs, whereby patients' expectations should always be assessed, as well as better drug dosage in order to reduce drug intake.

Back to nature: herbal treatment, environmental enrichment, and social play can protect against unpredictable chronic stress in Long-Evans rats (Rattus norvegicus)

The importance of integrative biobehavioral responses to complex challenges cannot be overlooked. In this study, the synergetic effects of icariin (a flavonoid present in the plant Epimedium brevicornum), natural enrichment (NaEn), and play behavior were investigated. Rats (n = 60) were assigned to standard housing or NaEn; these two groups were subsequently divided into controls, rats receiving icariin treatments, and rats receiving icariin and allowed to play with an individual from another cage. All rats were exposed to unpredictable mild stressors for 4 weeks. At the end of the treatment, a Forced Swim Task (FST) was conducted to assess emotional regulation during an inescapable acute challenge. Biological samples were collected weekly and before and after the FST to monitor endocrine changes. Corticosterone (CORT), dehydroepiandrosterone (DHEA), and testosterone (T) were assayed. We found that icariin had a significant effect on DHEA/CORT ratios and T levels. NaEn also had a significant effect on both CORT and DHEA, but not on T levels. Play did not appear to be significantly related to the endocrine changes. The strongest positive effects on emotional resilience were observed in NaEn rats that also received icariin. Our results confirmed that using multiple channels to stimulate adaptive responses can be effective in increasing the ability of an organism to face uncertainty. Considering how quickly our life can change due to unpredictable events, our data is instrumental to a better comprehension of the many aspects of integrative biobehavioral responses.

The Effects of Low Dose Naltrexone on Opioid Induced Hyperalgesia and Fibromyalgia

Objectives: While opioids temporarily alleviate pain, the overshoot of balancing pain drivers may increase pain, leading to opioid induced hyperalgesia (OIH). Our goal was to find out what chronic opioid treatment does to pain tolerance as measured by the cold pressor test (CPT), an objective measure of pain tolerance, and to find an alternative effective treatment for chronic pain and FM. Materials and Methods: The setting was an academic addiction medicine service that has an embedded pain service. Patients had routine clinical care starting with an evaluation that included assessment of medical and psychiatric conditions. Participants were 55 patients with OIH and 21 patients with fibromyalgia; all had at least two CPTs. Treatment included a single dose of buprenorphine for detoxification. In this open-label case series, patients were treated with low dose naltrexone (LDN), a pure opioid receptor antagonist that, we hypothesize, treats OIH and FM by restoring endogenous opioid tone. Results: Comparing initial and last CPT times, those with OIH more than quadrupled their pain tolerance, and those with FM doubled theirs. This improved pain tolerance for OIH and FM was statistically significant (p < 0.0001 and p = 0.003, respectively) and had a large effect size (r = 0.82 and r = 0.63, respectively). Discussion: Results suggest that patients on chronic opioid therapy should have pain tolerance measured by CPT with detoxification and LDN provided to correct opioid induced hyperalgesia if found. FM may also be treated with LDN. The main limitation of the findings was lack of a randomized control group treated with placebo.

Clinician-Patient Movement Synchrony Mediates Social Group Effects on Interpersonal Trust and Perceived Pain

Pain is an unfortunate consequence of many medical procedures, which in some patients becomes chronic and debilitating. Among the factors affecting medical pain, clinician-patient (C-P) similarity and nonverbal communication are particularly important for pain diagnosis and treatment. Participants (N = 66) were randomly assigned to clinician and patient roles and were grouped into C-P dyads. Clinicians administered painful stimuli to patients as an analogue of a painful medical procedure. We manipulated the perceived C-P similarity of each dyad using groups ostensibly based on shared beliefs and values, and each patient was tested twice: Once with a same group clinician (concordant, CC) and once with a clinician from the other group (discordant, DC). Movement synchrony was calculated as a marker of nonverbal communication. We tested whether movement synchrony mediated the effects of group concordance on patients' pain and trust in the clinician. Movement synchrony was higher in CC than DC dyads. Higher movement synchrony predicted reduced pain and increased trust in the clinician. Movement synchrony also formally mediated the group concordance effects on pain and trust. These findings increase our understanding of the role of nonverbal C-P communication on pain and related outcomes. Interpersonal synchrony may be associated with better pain outcomes, independent of the specific treatment provided. PERSPECTIVE: This article demonstrates that movement synchrony in C-P interactions is an unobtrusive measure related to their relationship quality, trust toward the clinician, and pain. These findings suggest that interpersonal synchrony may be associated with better patient outcomes, independent of the specific treatment provided.

Placebo effects on the quantity and quality of relaxation training

Many people find it difficult to practice progressive muscle relaxation (PMR) regularly. We attempted to improve relaxation quantity (i.e. adherence), and relaxation quality via placebo. A total of 100 women were randomly assigned to a standard group, which practiced PMR at home every day for two weeks, or a placebo group, which practiced PMR for two weeks with additional daily placebo treatment. To monitor adherence to relaxation practice, we used a smartphone app. The placebo group practiced more often than the standard group. Both groups did not differ in their reported relaxation level after the daily exercises.

Psychological interventions to foster resilience in healthcare students

BACKGROUND

Resilience can be defined as maintaining or regaining mental health during or after significant adversities such as a potentially traumatising event, challenging life circumstances, a critical life transition or physical illness. Healthcare students, such as medical, nursing, psychology and social work students, are exposed to various study- and work-related stressors, the latter particularly during later phases of health professional education. They are at increased risk of developing symptoms of burnout or mental disorders. This population may benefit from resilience-promoting training programmes.

OBJECTIVES

To assess the effects of interventions to foster resilience in healthcare students, that is, students in training for health professions delivering direct medical care (e.g. medical, nursing, midwifery or paramedic students), and those in training for allied health professions, as distinct from medical care (e.g. psychology, physical therapy or social work students).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, 11 other databases and three trial registries from 1990 to June 2019. We checked reference lists and contacted researchers in the field. We updated this search in four key databases in June 2020, but we have not yet incorporated these results.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any form of psychological intervention to foster resilience, hardiness or post-traumatic growth versus no intervention, waiting list, usual care, and active or attention control, in adults (18 years and older), who are healthcare students. Primary outcomes were resilience, anxiety, depression, stress or stress perception, and well-being or quality of life. Secondary outcomes were resilience factors.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data, assessed risks of bias, and rated the certainty of the evidence using the GRADE approach (at post-test only).

MAIN RESULTS

We included 30 RCTs, of which 24 were set in high-income countries and six in (upper- to lower-) middle-income countries. Twenty-two studies focused solely on healthcare students (1315 participants; number randomised not specified for two studies), including both students in health professions delivering direct medical care and those in allied health professions, such as psychology and physical therapy. Half of the studies were conducted in a university or school setting, including nursing/midwifery students or medical students. Eight studies investigated mixed samples (1365 participants), with healthcare students and participants outside of a health professional study field. Participants mainly included women (63.3% to 67.3% in mixed samples) from young adulthood (mean age range, if reported: 19.5 to 26.83 years; 19.35 to 38.14 years in mixed samples). Seventeen of the studies investigated group interventions of high training intensity (11 studies; > 12 hours/sessions), that were delivered face-to-face (17 studies). Of the included studies, eight compared a resilience training based on mindfulness versus unspecific comparators (e.g. wait-list). The studies were funded by different sources (e.g. universities, foundations), or a combination of various sources (four studies). Seven studies did not specify a potential funder, and three studies received no funding support. Risk of bias was high or unclear, with main flaws in performance, detection, attrition and reporting bias domains. At post-intervention, very-low certainty evidence indicated that, compared to controls, healthcare students receiving resilience training may report higher levels of resilience (standardised mean difference (SMD) 0.43, 95% confidence interval (CI) 0.07 to 0.78; 9 studies, 561 participants), lower levels of anxiety (SMD -0.45, 95% CI -0.84 to -0.06; 7 studies, 362 participants), and lower levels of stress or stress perception (SMD -0.28, 95% CI -0.48 to -0.09; 7 studies, 420 participants). Effect sizes varied between small and moderate. There was little or no evidence of any effect of resilience training on depression (SMD -0.20, 95% CI -0.52 to 0.11; 6 studies, 332 participants; very-low certainty evidence) or well-being or quality of life (SMD 0.15, 95% CI -0.14 to 0.43; 4 studies, 251 participants; very-low certainty evidence). Adverse effects were measured in four studies, but data were only reported for three of them. None of the three studies reported any adverse events occurring during the study (very-low certainty of evidence).

AUTHORS' CONCLUSIONS

For healthcare students, there is very-low certainty evidence for the effect of resilience training on resilience, anxiety, and stress or stress perception at post-intervention. The heterogeneous interventions, the paucity of short-, medium- or long-term data, and the geographical distribution restricted to high-income countries limit the generalisability of results. Conclusions should therefore be drawn cautiously. Since the findings suggest positive effects of resilience training for healthcare students with very-low certainty evidence, high-quality replications and improved study designs (e.g. a consensus on the definition of resilience, the assessment of individual stressor exposure, more attention controls, and longer follow-up periods) are clearly needed.

Electroacupuncture for post-stroke overactive bladder: a multi-centre pilot randomized controlled trial

BACKGROUND

Although acupuncture has been shown to be effective at treating overactive bladder (OAB) following stroke, to our knowledge, no randomized controlled trial (RCT) examining the effects of acupuncture on patients with post-stroke OAB has been conducted. The aim of this preliminary study was to explore the effects of electroacupuncture (EA) in the treatment of post-stroke OAB.

METHODS

This study was a multi-site randomized, assessor-blind, controlled pilot trial of patients with post-stroke OAB. In all, 34 post-stroke subjects (mean age: 71.0 years; 32.4% female) with OAB symptoms were randomly assigned to the treatment group or control group in a 1:1 ratio. The subjects in the treatment group were treated with six sessions of EA for 4 weeks, while the subjects in the control group received usual care. The primary outcome measure was the overactive bladder symptom scale (OABSS). Secondary outcome measures included a three day bladder diary and the stroke-specific quality-of-life scale (SSQoL).

RESULTS

EA showed a moderate effect size (ES) on the perceived severity of OAB symptoms as measured by the OABSS at week 5 (one week post-treatment, ES 0.57; p = 0.034) and week 8 (three weeks post-treatment, ES 0.60; p = 0.021), although the results did not remain statistically significant after Bonferroni correction for multiple testing. No significant differences in bladder diary parameters or SSQoL score were found. The EA treatment was well tolerated by the post-stroke subjects.

CONCLUSION

A six-session EA treatment was feasible and appeared to reduce OAB symptoms in post-stroke patients. Further fully powered trials are warranted to confirm the efficacy of EA for those with post-stroke OAB.

Nocebo and lessebo effects

The power of placebos is commonly associated with the placebo effect. In contrast, detrimental effects related to the use of a placebo are little studied and less well recognized. This chapter covers the nocebo and lessebo effects defined, respectively, as expectation of harm in the form of adverse events in a placebo arm and reduction of therapeutic benefit due to the uncertainty of being allocated to placebo. The lessebo effect is a more recent concept and has been described only in depression, schizophrenia and Parkinson's disease. The nocebo response was evaluated in many neurological diseases, including epilepsy, multiple sclerosis, Parkinson's disease, Alzheimer's disease, restless leg syndrome, among others. Meta-analyses of randomized controlled trials in these conditions reveal a significant variability of the magnitude of the nocebo response and that factors related to study design, study participants or neurological disease can be associated with a nocebo response, although with the opposing findings across conditions. The knowledge about neurobiological mechanisms of the nocebo effect is poor for neurological diseases, and most of the information has been generated in pain. Functional neuroimaging suggests the existence of a distinct network for the anticipation and the experience of a hyperalgesia nocebo response. Different types of neurotransmitters have been involved, including cholecystokinin, dopamine and opioids. Recognizing the potential impact of nocebo and lessebo effects, mitigating strategies are in development with application to clinical research and clinical practice, such as a contextualized informed consent process, alternative study designs and enhancement of patient-physician communication.