How placebos change the patient's brain

Autosuggestion: a cognitive process that empowers your brain?

Autosuggestion is a cognitive process that is believed to enable control over one's own cognitive and physiological states. Despite its potential importance for basic science and clinical applications, such as in rehabilitation, stress reduction, or pain therapy, the neurocognitive mechanisms and psychological concepts that underlie autosuggestion are poorly defined. Here, by reviewing empirical data on autosuggestion and related phenomena such as mental imagery, mental simulation, and suggestion, we offer a neurocognitive concept of autosuggestion. We argue that autosuggestion is characterized by three major factors: reinstantiation, reiteration, and volitional, active control over one's own physiological states. We also propose that autosuggestion might involve the 'overwriting' of existing predictions or brain states that expect the most common (but not desired) outcome. We discuss potential experimental paradigms that could be used to study autosuggestion in the future, and discuss the strengths and weaknesses of current evidence. This review provides a first overview on how to define, experimentally induce, and study autosuggestion, which may facilitate its use in basic science and clinical practice.

Functional Neuroimaging Correlates of Placebo Response in Patients With Depressive or Anxiety Disorders: A Systematic Review

BACKGROUND

The mechanisms underlying placebo effects of psychotropic drugs remain poorly understood. We carried out the first, to our knowledge, systematic review of functional neuroimaging correlates of placebo response in adults with anxiety/depressive disorders.

METHODS

We systematically searched a large set of databases up to February 2021 based on a pre-registered protocol (PROSPERO CRD42019156911). We extracted neuroimaging data related to clinical improvement following placebo or related to placebo mechanisms. We did not perform a meta-analysis due to the small number of included studies and significant heterogeneity in study design and outcome measures.

RESULTS

We found 12 relevant studies for depressive disorders and 4 for anxiety disorders. Activity in the ventral striatum, rostral anterior cingulate cortex and other default mode network regions, orbitofrontal cortex, and dorsolateral prefrontal cortex correlated with placebo antidepressant responses. Activity in regions of the default mode network, including posterior cingulate cortex, was associated with placebo anxiolysis. There was also evidence for possible involvement of the endogenous opioid, dopamine, and serotonin systems in placebo antidepressant and anxiolytic effects.

CONCLUSIONS

Several brain regions and molecular systems may be involved in these placebo effects. Further adequately powered studies exploring causality and controlling for confounders are required.

Placebo nasal spray protects female participants from experimentally induced sadness and concomitant changes in autonomic arousal

BACKGROUND

To investigate the powerful placebo effects in antidepressant drug trials and their mechanisms, recent pioneering experimental studies showed that expectation manipulation combined with an active placebo attenuated induced sadness. In the present study, we aimed at extending these findings by assessing the psychophysiological response in addition to mere self-report.

METHODS

One hundred and thirteen healthy female students were randomly assigned to a drug expectation group (active placebo, positive treatment expectation), placebo expectation group (active placebo, no treatment expectation), or a no-treatment group (no placebo, no treatment expectation). After placebo intake, sadness was induced by self-deprecating statements using the Velten method combined with sad music, including a rumination phase. Sadness was measured using the Positive and Negative Affect Schedule Expanded Form (PANAS-X). Heart rate and skin conductance were assessed continuously.

RESULTS

After mood induction and after rumination, self-reported sadness was significantly lower, and skin conductance level was significantly higher, in the drug expectation group than in the no-treatment group. The mood induction was further accompanied by a heart rate deceleration within all groups.

LIMITATIONS

Generalizability is limited by sample selectivity and focusing on sadness as a symptom of depression, exclusively.

CONCLUSION

Expectation-induced placebo effects significantly influenced sadness-correlated changes in autonomic arousal, and not only subjectively reported sadness, indicating that placebo effects in the context of affect are not merely due to subjective response bias. The systematic modification of treatment expectation could be utilized in clinical practice to optimize current therapeutic approaches to improve mood regulation.

Diverse predictors of treatment response to active medication and placebo in gambling disorder

Gambling disorder creates a significant public health burden. Despite decades of clinical trials, there are no licensed pharmacological treatments for gambling disorder. Contributing factors to this are the high placebo response rates seen in clinical trials, the heterogeneity of the disorder and high rates of psychiatric comorbidities. Indeed, a number of demographic and clinical variables have previously been associated with altered responses to pharmacotherapy, psychotherapy and placebo. Which variables are likely to predict response to one modality over another remains uncertain. We carried out multiple linear regression analyses in a pooled dataset from six treatment studies in gambling disorder with the aim of identifying predictors of treatment response. Potential predictors were identified a priori through hypothesis and entered into models including all patients, and subsequently for those randomized to active medication or placebo separately. We found that baseline severity of gambling symptoms and number of weeks completed in a trial were predictors of active medication response, while decreased baseline symptoms of anxiety, increased baseline symptoms of depression, and non-Caucasian ethnicity were associated with placebo response. Sensitivity analyses showed that these associations were robust to choices made during the analysis. Further research is required to understand whether controlling for these variables, or using enriched samples, improves assay sensitivity in placebo-controlled clinical trials for gambling disorder.

The Role of Expectation and Beliefs on the Effects of Non-Invasive Brain Stimulation

Non-invasive brain stimulation (NIBS) techniques are used in clinical and cognitive neuroscience to induce a mild magnetic or electric field in the brain to modulate behavior and cortical activation. Despite the great body of literature demonstrating promising results, unexpected or even paradoxical outcomes are sometimes observed. This might be due either to technical and methodological issues (e.g., stimulation parameters, stimulated brain area), or to participants’ expectations and beliefs before and during the stimulation sessions. In this narrative review, we present some studies showing that placebo and nocebo effects, associated with positive and negative expectations, respectively, could be present in NIBS trials, both in experimental and in clinical settings. The lack of systematic evaluation of subjective expectations and beliefs before and after stimulation could represent a caveat that overshadows the potential contribution of placebo and nocebo effects in the outcome of NIBS trials.

Differential power of placebo across major psychiatric disorders: a preliminary meta-analysis and machine learning study

The placebo effect across psychiatric disorders is still not well understood. In the present study, we conducted meta-analyses including meta-regression, and machine learning analyses to investigate whether the power of placebo effect depends on the types of psychiatric disorders. We included 108 clinical trials (32,035 participants) investigating pharmacological intervention effects on major depressive disorder (MDD), bipolar disorder (BD) and schizophrenia (SCZ). We developed measures based on clinical rating scales and Clinical Global Impression scores to compare placebo effects across these disorders. We performed meta-analysis including meta-regression using sample-size weighted bootstrapping techniques, and machine learning analysis to identify the disorder type included in a trial based on the placebo response. Consistently through multiple measures and analyses, we found differential placebo effects across the three disorders, and found lower placebo effect in SCZ compared to mood disorders. The differential placebo effects could also distinguish the condition involved in each trial between SCZ and mood disorders with machine learning. Our study indicates differential placebo effect across MDD, BD, and SCZ, which is important for future neurobiological studies of placebo effects across psychiatric disorders and may lead to potential therapeutic applications of placebo on disorders more responsive to placebo compared to other conditions.

(-)-OSU6162 in the treatment of fatigue and other sequelae after aneurysmal subarachnoid hemorrhage: a double-blind, randomized, placebo-controlled study

OBJECTIVE

Fatigue after aneurysmal subarachnoid hemorrhage (aSAH) is common and usually long-lasting, and it has a considerable negative impact on health-related quality of life (HRQOL), social functioning, and the ability to return to work (RTW). No effective treatment exists. The dopaminergic regulator (-)-OSU6162 has shown promising results regarding the mitigation of fatigue in various neurological diseases, and therefore the authors aimed to investigate the efficacy of (-)-OSU6162 in alleviating fatigue and other sequelae after aSAH.

METHODS

A double-blind, randomized, placebo-controlled, single-center trial was performed in which 96 participants with post-aSAH fatigue were administered 30-60 mg/day of (-)-OSU6162 or placebo over a period of 12 weeks. Efficacy was assessed using the Fatigue Severity Scale (FSS), the Mental Fatigue Scale (MFS), the Beck Anxiety Inventory (BAI), the Beck Depression Inventory II (BDI-II), the SF-36 questionnaire, and a neuropsychological test battery. Assessments were performed at baseline, after 1, 4, 8, and 12 weeks of treatment, and at follow-up, 8 weeks after treatment.

RESULTS

The 96 participants with post-aSAH fatigue were randomized to treatment with (-)-OSU6162 (n = 49) or placebo (n = 47). The FSS, MFS, and BDI scores improved significantly in both groups after 12 weeks of treatment, whereas the BAI scores improved in the placebo group only. HRQOL improved significantly in the SF-36 domain "Vitality" in both groups. Neuropsychological test performances were within the normal range at baseline and not affected by treatment. The FSS score was distinctly improved in patients with complete RTW upon treatment with (-)-OSU6162. Concomitant use of antidepressants improved the efficacy of (-)-OSU6162 on the FSS score at week 1 beyond the placebo response, and correspondingly the use of beta- or calcium-channel blockers improved the (-)-OSU6162 efficacy beyond the placebo response in MFS scores at week 4 of treatment. There was a significant correlation between improvement in FSS, BAI, and BDI scores and the plasma concentration of (-)-OSU6162 at the dose of 60 mg/day. No serious adverse events were attributable to the treatment, but dizziness was reported more often in the (-)-OSU6162 group.

CONCLUSIONS

Fatigue and other sequelae after aSAH were similarly alleviated by treatment with (-)-OSU6162 and placebo. (-)-OSU6162 improved fatigue, as measured with the FSS score, significantly in patients with complete RTW. There seemed to be synergetic effects of (-)-OSU6162 and medications interfering with dopaminergic pathways that should be explored further. The strong placebo response may be exploited in developing nonpharmacological treatment programs for post-aSAH fatigue.

Central sensitization, illness perception and obesity should be considered when interpreting disease activity in axial spondyloarthritis

OBJECTIVES

Many patients with axial spondyloarthritis (axSpA) report persistent pain even when treated with anti-inflammatory agents. Our aim was to explore the presence of central sensitization (CS) and different types of illness perceptions in patients with axSpA, and to assess their associations with disease activity assessments.

METHODS

Consecutive outpatients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort were included. Besides standardized assessments, patients filled out the Central Sensitization Inventory (CSI), Illness Perception Questionnaire (IPQ-R) and Pain Catastrophizing Scale (PCS). Univariable and multivariable linear regression analyses were used to investigate the association between questionnaire scores, patient characteristics and disease activity assessments ASDASCRP, BASDAI and CRP.

RESULTS

We included 182 patients with a mean symptom duration of 21.6 years. Mean ASDASCRP was 2.1, mean BASDAI 3.9, and median CRP 2.9. Mean CSI score was 37.8 (scale 0-100) and 45% of patients scored ≥40, indicating a high probability of CS. CSI score, IPQ-R domain identity (number of symptoms the patient attributes to their illness), and IPQ-R domain treatment control (perceived treatment efficacy), and obesity were significantly and independently associated with both ASDASCRP and BASDAI, explaining a substantial proportion of variation in these disease activity scores (R2=0.35 and R2=0.47, respectively). Only obesity was also independently associated with CRP.

CONCLUSION

CS may be common in patients with long-term axSpA. CS, as well as specific illness perceptions and obesity were all independently associated with the widely used (partially) patient-reported disease activity assessments ASDASCRP and BASDAI. Treating physicians should take this into account in the follow-up and treatment of their patients.

Cutoff criteria for the placebo response: a cluster and machine learning analysis of placebo analgesia

Computations of placebo effects are essential in randomized controlled trials (RCTs) for separating the specific effects of treatments from unspecific effects associated with the therapeutic intervention. Thus, the identification of placebo responders is important for testing the efficacy of treatments and drugs. The present study uses data from an experimental study on placebo analgesia to suggest a statistical procedure to separate placebo responders from nonresponders and suggests cutoff values for when responses to placebo treatment are large enough to be separated from reported symptom changes in a no-treatment condition. Unsupervised cluster analysis was used to classify responders and nonresponders, and logistic regression implemented in machine learning was used to obtain cutoff values for placebo analgesic responses. The results showed that placebo responders can be statistically separated from nonresponders by cluster analysis and machine learning classification, and this procedure is potentially useful in other fields for the identification of responders to a treatment.

[Scientific medicine and care relationship: From the therapeutic alliance to the therapeutic effect of the alliance]

The new paradigm of precision medicine in oncology questions today the respective place of evidence-based medicine and doctor-patient relationship. Based on the results of a randomized study comparing the efficacy of a homeopathic molecule in the prevention of nausea and vomiting induced by chemotherapy in non-metastatic breast cancer, this article extends and develops the discussion of maintaining an unresolved tension between medical art and medical science, between care and cure. This tension sets a base for the authors of the therapeutic alliance in medicine, defined as a dialectic constantly adjourned between the alliance of the doctor with the patient and his therapy, and the therapeutic effect of this alliance. Because if a policy or a public opinion were to promote an exclusively rational medicine deprived of the field of relation to care, or on the contrary a medicine based only on clinical sense and intuition, then respectively the ethics of care and the progress of therapy would be threatened. It is advisable to be aware of erring from the truth, amplified today by social networks, as much due to a tide of scientific positivism, as an excess of the "good caring soul". Taking into account the therapeutic alliance makes it possible to no longer oppose scientific medicine and care relationship.

Placebo effect in children: the role of expectation and learning

Classical conditioning and expectations are well-known underlying mechanisms of placebo hypoalgesia. Only little is known about their differential effect in adults, however, and even less in children. Previous studies in children evoked placebo hypoalgesia either with expectations alone or in combination with classical conditioning and revealed conflicting results. Furthermore, these studies investigated children of different ages making it even more difficult to draw conclusions. This study tried to disentangle classical conditioning and expectations by investigating them separately. To examine age effects, n = 172 children (6-9, 10-13, and 14-17 years) as well as n = 32 adults (> = 18 years) were tested using a heat pain paradigm investigating the effectiveness of creams some of which were bogusly introduced as analgesic. In addition to subjective pain intensity ratings, peripheral physiological measures were recorded. Results showed a successful induction of placebo hypoalgesia by both mechanisms for pain ratings and heart rate acceleration. Placebo hypoalgesia was particularly pronounced in children younger than 14 years. Furthermore, placebo hypoalgesia was more marked in children whose mothers raised the expectations. It was also stronger in participants who noticed a strong pain reduction during learning trials. These results encourage the use of placebo effect in clinical practice, particularly for younger children. They underline the relevance of an initial pain reduction and encourage the inclusion of parents in treatment.

The Effect of Information Placebo on Physical Activity in Overweight and Obese Children

PURPOSE

To assess the effect of 1 week of consuming a placebo "energy drink" compared with a week of drinking regular water on daily physical activity in obese children participating in a weight reduction multidisciplinary program.

METHODS

Seventeen prepubertal (age = 128.7 [26.6] m) overweight and obese children (7 females and 10 males) participated in the study. Participants received 7 bottles of mineral water per week for 2 weeks. Different types of information were randomly provided regarding the drink consumed in each week: standard (water) versus deliberate positive information (presumed energy drink and placebo). Daily step count was measured using pedometers and compared using paired t test.

RESULTS

After consuming the placebo drink, children demonstrated a significantly higher average daily step number (10,452 [4107]) compared with the days they drank water (8168 [2928], P < .005). This difference was attributed mainly to male participants.

CONCLUSION

The use of placebo in the form of deliberate positive information was associated with a significant increase in real-life physical activity in overweight and obese children, especially in boys. Positive information may be used to encourage children with obesity to enhance daily physical activity and energy expenditure.

Examining the Relationship Between Patient Fatigue-Related Symptom Clusters and Carer Depressive Symptoms in Advanced Cancer Dyads: A Secondary Analysis of a Large Hospice Data Set

BACKGROUND

Most symptom management takes place in the community, conducted by patient and/or informal carer dyads with guidance from clinicians. Given the prevalence of cancer, there is a critical need for examination of the impact of managing multiple symptoms, particularly those that cluster with fatigue, on informal carers.

OBJECTIVES

To (1) examine clustering of patient fatigue-related symptom severity and distress in individuals with cancer and (2) test the hypothesis that patient fatigue-related symptom clusters (severity, distress) will be positively associated with carer depressive symptoms.

METHODS

Secondary analysis of 689 hospice patient/informal carer dyads using exploratory factor analysis and structural equation modeling. Patient symptoms were measured by the Memorial Symptom Assessment Scale, and carer depressive symptoms were measured by the Center for Epidemiological Study-Depression Scale.

RESULTS

Patients were 73 (SD, 12) years old, and 43% were female. Carers were 65 years (SD, 14) years old, and 74% were female. For symptom severity, dyspnea, dry mouth, lack of appetite, drowsiness, cough, dizziness, and difficulty swallowing clustered with fatigue. For symptom distress, dyspnea, cough, and dry mouth clustered with fatigue. Structural equation modeling results indicated that the patient fatigue severity cluster was positively related to carer depressive symptoms (b = 0.12, P < .05), but distress was not.

CONCLUSION

Managing multiple symptoms that cluster with fatigue negatively impacts informal carers.

IMPLICATIONS FOR PRACTICE

When patients complain of severe fatigue, clinicians need to explore all causes and ask about other symptoms while exploring whether the informal carer is feeling burdened or depressed.

Unblinding in Randomized Controlled Trials: A Research Ethics Case

A pregnant woman was enrolled in a double-blind randomized controlled trial (RCT) in which participants were randomized to a placebo or a drug being tested to prevent a hypertensive complication. After completing the trial, the research participant insisted on being told which drug she received to prepare for a future pregnancy. This case highlights an element of RCT procedure that has received minimal attention-whether to unblind study participants at the end of their participation. Given that unblinding is not standard practice for nonserious adverse events, what actions are justifiable for the investigators to take? To synthesize the information about this case, we used the CASES model, created by the National Center for Ethics in Health Care to analyze ethics cases. Ethical principles that guide research emphasize communication with participants and the importance of reducing harm within the constraints of the scientific goals. Participants may value knowing which drug they received for future health care decision-making. We review information about the benefits and harms of unblinding.

Placebo effects in allergen immunotherapy-An EAACI Task Force Position Paper

The placebo (Latin "I will please") effect commonly occurs in clinical trials. The psychological and physiological factors associated with patients' expectations about a treatment's positive and negative effects have yet to be well characterized, although a functional prefrontal cortex and intense bidirectional communication between the central nervous system and the immune system appear to be prerequisites for a placebo effect. The use of placebo raises certain ethical issues, especially if patients in a placebo group are denied an effective treatment for a long period of time. The placebo effect appears to be relatively large (up to 77%, relative to pretreatment scores) in controlled clinical trials of allergen immunotherapy (AIT), such as the pivotal, double-blind, placebo-controlled (DBPC) randomized clinical trials currently required by regulatory authorities worldwide. The European Academy of Allergy and Clinical Immunology (EAACI) therefore initiated a Task Force, in order to better understand the placebo effect in AIT and its specific role in comorbidities, blinding issues, adherence, measurement time points, variability and the natural course of the disease. In this Position Paper, the EAACI Task Force highlights several important topics regarding the placebo effect in AIT such as a) regulatory aspects, b) neuroimmunological and psychological mechanisms, c) placebo effect sizes in AIT trials, d) methodological limitations in AIT trial design and e) potential solutions in future AIT trial design. In conclusion, this Position Paper aims to examine the methodological problem of placebo in AIT from different aspects and also to highlight unmet needs and possible solutions for future trials.

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.

Medication Beliefs and Adherence to Antiseizure Medications

Introduction

The primary objective of our study was to determine the nature of medication beliefs and their association with adherence to antiseizure medications (ASMs) among elderly epilepsy patients. Our secondary objective was to enhance the psychometric properties and factor structure parameters of the Beliefs about Medications Questionnaire (BMQ) adapted to epilepsy and affected aged subjects.

Methods

A population-based survey was performed in which older adults (≥60 years of age) were invited for a free face-to-face consultation with the specialists as well as for the collection of necessary data. The eligible subjects were those who are affected with epilepsy and having epileptic seizures of any type. In addition, the participants were required to be of any sex, currently under treatment with ASMs, resident of Tehran, and able and interested to participate independently. All were carefully examined with a reasonably detailed case-history examination. Two Persian questionnaires used were Medication Adherence Rating Scale (MARS) and BMQ. Those with a MARS score of ≥6 were considered as adherent to ASMs. All data were described in descriptive terms. We did a group comparison of means and proportions for all possible independent variables between adherents and nonadherents. Then, we did a hierarchical multiple linear regression. For this, independent variables were categorized into three different blocks: (a) sociodemographic block (Block-1), (b) treatment side-effect block (Block-2), and (c) BMQ block that included ten items of the BMQ scale (Block-3). We also did a forward step-wise linear regression by beginning with an empty model. We also estimated the psychometric properties and factor structure parameters of BMQ and its two subdomains.

Results

Of all (N = 123, mean age: 63.3 years, 74.0% males), 78.0% were adherent (mean score: 7.0, 95% CI 6.2–7.8) to ASMs. The MARS scores were not different between males and females. The mean BMQ score was 23.4 (95% CI 19.8–27.0) with the mean need score of 20.0 (95% CI 18.0–22.0) and mean concern score of 16.5 (95% CI 14.3–18.7). A positive need-concern differential was 20.4%. Upon hierarchical regression, the adjusted R² for Block-1 was 33.8%, and it was 53.8% for Block-2 and 92.2% for Block-3. Upon forward step-wise linear regression, we found that “ASMs disrupt my life” (ß −1.9, ES = −1.1, p=0.008) as the only belief associated with adherence. The alpha coefficient of BMQ was 0.81.

Conclusions

Ours is one of the very few studies that evaluated medication beliefs and their association with adherence to ASMs among elderly epilepsy patients in a non-western context. In our context, medication beliefs are likely to have an independent role in effecting adherence to ASMs, particularly the concern that “ASMs disrupt life.” Treating physicians should cultivate good conscience about ASMs and evaluate the patient's medication beliefs early-on to identify those who might be at the risk of becoming nonadherent.

Why we need more research into the placebo response in psychiatry

Placebos are not inert, but exert measurable biological effects. The placebo response in psychiatric illness is important and clinically relevant, but remains poorly understood. In this paper, we review current knowledge about the placebo response in psychiatric medicine and identify research directions for the future. We argue that more research is needed into the placebo response in psychiatric medicine for three broad reasons. First, awareness of factors that cause placebo response, for whom, and when, within clinical trials will allow us to better evidence efficacy of new treatments. Second, by understanding how placebo mechanisms operate in the clinic, we can take advantage of these to optimise the effects of current treatments. Finally, exploring the biological mechanisms of placebo effects might reveal tractable targets for novel treatment development.

Glucose metabolism responds to perceived sugar intake more than actual sugar intake

The authors examine study participants who have Type 2 diabetes to determine whether cognition affects glucose levels in contrast to widely held suppositions. Thirty participants who have type 2 diabetes consume beverages that have identical ingredients but have deceptive nutrition facts labels. Blood glucose levels measured four times before and after beverage consumption show that blood glucose levels increase when participants believe the beverage has high sugar content as portrayed on the labels. Also, individual eating behaviors and nutritional satisfaction are linked to changes in blood glucose levels. The study results support the concept of anticipatory budgeting on glucose metabolism. The findings provide pressing evidence for the psychobiological model of chronic disease, suggesting that psychological intervention programs may be important for diabetes management, beyond current programs in which type 2 diabetes is managed through diet, exercise, and medications only.

Antipruritic Placebo Effects by Conditioning H1-antihistamine

OBJECTIVE

Allergic rhinitis symptoms can be reduced by behaviorally conditioning antihistamine. It is unclear whether these findings extend to histamine-induced itch or work when participants are informed about the conditioning procedure (open-label conditioning). The current study aims to investigate the efficacy of (open-label) antipruritic behavioral conditioning for histamine-induced itch.

METHODS

Healthy participants (n = 92; 84% female) were randomized to I) an open-label conditioned, II) closed-label conditioned, III) conditioned-not-evoked control, or IV) nonconditioned control group. A two-phase conditioning paradigm was used. During acquisition, a conditioned stimulus (CS; distinctively tasting beverage) was repeatedly paired with the H1-antihistamine levocetirizine (groups I-III). During evocation, the CS was paired with placebo (I, II), or instead of the CS, water was paired with placebo (III). The nonconditioned control group (IV) received CS with placebo in both phases. Itch after histamine iontophoresis and physiological data (i.e., spirometry, heart rate, skin conductance) were assessed. Combined conditioned and combined control groups were first compared, and analyses were repeated for separate groups.

RESULTS

Marginally lower itch was reported in the combined conditioned compared with the control groups (F(1,88) = 2.10, p = .076, ηpartial = 0.02); no differences between separate groups were found. No effects on physiological data were found, except for heart rate, which reduced significantly and consistently for control groups, and less consistently for conditioned groups (group by time interaction: F(7,80) = 2.35, p = .031, ηpartial = 0.17).

CONCLUSION

Limited support was found for the efficacy of antipruritic behavioral conditioning, regardless of whether participants were informed about the conditioning procedure. The application of open-label conditioning in patient populations should be further researched.

TRIAL REGISTRATION

www.trialregister.nl; ID NTR5544.

Context matters: the psychoneurobiological determinants of placebo, nocebo and context-related effects in physiotherapy

Background

Placebo and nocebo effects embody psychoneurobiological phenomena where behavioural, neurophysiological, perceptive and cognitive changes occur during the therapeutic encounter in the healthcare context. Placebo effects are produced by a positive healthcare context; while nocebo effects are consequences of negative healthcare context. Historically, placebo, nocebo and context-related effects were considered as confounding elements for clinicians and researchers. In the last two decades this attitude started to change, and the understanding of the value of these effects has increased. Despite the growing interest, the knowledge and the awareness of using the healthcare context to trigger placebo and nocebo effects is currently limited and heterogeneous among physiotherapists, reducing their translational value in the physiotherapy field.

Objectives

To introduce the placebo, nocebo and context-related effects by: (1) presenting their psychological models; (2) describing their neurophysiological mechanisms; (3) underlining their impact for the physiotherapy profession; and (4) tracing lines for future researches.

Conclusion

Several psychological mechanisms are involved in placebo, nocebo and context-related effects; including expectation, learning processes (classical conditioning and observational learning), reinforced expectations, mindset and personality traits. The neurophysiological mechanisms mainly include the endogenous opioid, the endocannabinoid and the dopaminergic systems. Neuroimaging studies have identified different brain regions involved such as the dorsolateral prefrontal cortex, the rostral anterior cingulate cortex, the periaqueductal gray and the dorsal horn of spine. From a clinical perspective, the manipulation of the healthcare context with the best evidence-based therapy represents an opportunity to trigger placebo effects and to avoid nocebo effects respecting the ethical code of conduct. From a managerial perspective, stakeholders, organizations and governments should encourage the assessment of the healthcare context aimed to improve the quality of physiotherapy services. From an educational perspective, placebo and nocebo effects are professional topics that should be integrated in the university program of health and medical professions. From a research perspective, the control of placebo, nocebo and context-related effects offers to the scientific community the chance to better measure the impact of physiotherapy on different outcomes and in different conditions through primary studies.

Determinants of placebo effects

Determinants of placebo effects and placebo response can be considered from multiple intrinsic and extrinsic perspectives. Intrinsic factors may influence the patient and the clinician/researcher. Patient expectations and previous experiences are considered two of the major intrinsic determinants of placebo response. Other patient determinants include the neural systems under treatment/study, situational factors and reactions to the environment, and personality traits. Clinician/researcher determinants of placebo response include personality factors such as empathy, perceived expertise, the clinical relationship with the patient, and the clinician's belief in the efficacy of the treatment. Extrinsic determinants include the type of study design, influence of advertising or branding, and forces expressed by the cultural milieu. These determinants do not act in isolation, but rather form a complex interaction that ultimately impacts the promotion or deterrence of the placebo effect in clinical and research settings.

Placebo Brain Stimulation Affects Subjective but Not Neurocognitive Measures of Error Processing

The aim of this preregistered EEG study was to show how expectations about enhanced or impaired performance through transcranial stimulation affect feelings of agency and error processing. Using a single-blind experimental design, participants (N = 57) were attached to a transcranial direct current stimulation (tDCS) device, and in different blocks, they were verbally instructed to expect enhanced or impaired cognitive performance, or no effects of the brain stimulation. In all cases, but unbeknownst to the participants, we used an inert sham tDCS protocol. Subsequently, we measured their response to errors on a cognitive control task. Our expectancy manipulation was successful: participants reported improved subjective performance in the enhancement compared with the impairment condition—even though objective performance was kept at a constant level across conditions. Participants reported the highest feelings of agency over their task performance in the control condition, and lowest feelings of agency in the impairment condition. The expectancy manipulation did not affect the error-related negativity (ERN) in association with incorrect responses. During the induction phase, expecting impaired versus enhanced performance increased frontal theta power, potentially reflecting a process of increased cognitive control allocation. Our findings show that verbally induced manipulations can affect subjective performance on a cognitive control task, but that stronger manipulations (e.g., through conditioning) are necessary to induce top-down effects on neural error processing.

Advancing the understanding of placebo effects in psychological outcomes of exercise: Lessons learned and future directions

Despite the apparent strength of scientific evidence suggesting that psychological benefits result from both acute and chronic exercise, concerns remain regarding the extent to which these benefits are explained by placebo effects. Addressing these concerns is methodologically and at times conceptually challenging. However, developments in the conceptualisation and study of placebo effects from the fields of psychology, neuroscience, pharmacology, and human performance offer guidance for advancing the understanding of placebo effects in psychological responses to exercise. In clinical trials, expectations can be measured and experimentally manipulated to better understand the influence of placebo effects on treatment responses. Further, compelling evidence has shown that the contribution of placebo effects and their underlying neurobiological mechanisms to treatment effects can be measured without administering a traditional placebo (e.g. inert substance) by leveraging psychological factors such as expectations and conditioning. Hence, the purpose of this focused review is to integrate lessons such as these with the current body of literature on placebo effects in psychological responses to exercise and provide recommendations for future research directions.

Incorporating methods and findings from neuroscience to better understand placebo and nocebo effects in sport

Placebo and nocebo effects are a factor in sports performance. However, the majority of published studies in sport science are descriptive and speculative regarding mechanisms. It is therefore not unreasonable for the sceptic to argue that placebo and nocebo effects in sport are illusory, and might be better explained by variations in phenomena such as motivation. It is likely that, in sport at least, placebo and nocebo effects will remain in this empirical grey area until researchers provide stronger mechanistic evidence. Recent research in neuroscience has identified a number of consistent, discrete and interacting neurobiological and physiological pathways associated with placebo and nocebo effects, with many studies reporting data of potential interest to sport scientists, for example relating to pain, fatigue and motor control. Findings suggest that placebos and nocebos result in activity of the opioid, endocannabinoid and dopamine neurotransmitter systems, brain regions including the motor cortex and striatum, and measureable effects on the autonomic nervous system. Many studies have demonstrated that placebo and nocebo effects associated with a treatment, for example an inert treatment presented as an analgesic or stimulant, exhibit mechanisms similar or identical to the verum or true treatment. Such findings suggest the possibility of a wide range of distinct placebo and nocebo mechanisms that might influence sports performance. In the present paper, we present some of the findings from neuroscience. Focussing on fatigue as an outcome and caffeine as vehicle, we propose three approaches that researchers in sport might incorporate in their studies in order to better elucidate mechanisms of placebo/nocebo effects on performance.

Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials

Bremelanotide significantly improves sexual desire and related distress in premenopausal women with hypoactive sexual distress disorder and has a favorable safety profile.

To evaluate the safety and efficacy of bremelanotide for the treatment of premenopausal women with hypoactive sexual desire disorder.

Placebo Responses Among Men With Erectile Dysfunction Enrolled in Phosphodiesterase 5 Inhibitor Trials: A Systematic Review and Meta-analysis

IMPORTANCE

Placebo responses in the treatment of erectile dysfunction (ED) are poorly described in the literature to date.

OBJECTIVE

To quantify the association of placebo with ED outcomes among men enrolled in placebo-controlled, phosphodiesterase 5 inhibitor (PDE5I) trials.

DATA SOURCES

For this systematic review and meta-analysis, a database search was conducted to identify double-blind, placebo-controlled studies using PDE5Is for the treatment of ED published from January 1, 1998, to December 31, 2018, within MEDLINE, Embase, Cochrane Library, and Web of Science. Only articles published in the English language were included.

STUDY SELECTION

Double-blind, placebo-controlled randomized clinical trials of PDE5Is for ED were included. Studies were excluded if they did not provide distribution measures for statistical analysis. Study selection review assessments were conducted by 2 independent investigators. A total of 2215 studies were identified from the database search, and after review, 63 studies that included 12 564 men were analyzed.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in abstracting data and assessing validity. Data were extracted from published reports by 2 independent reviewers. Quality assessment was performed using the Jadad scale. Data were pooled using a random-effects model.

MAIN OUTCOMES AND MEASURES

The main outcome was improvement in the erectile function domain of the International Index of Erectile Function questionnaire in the placebo arm of the included studies. Effect size was reported as bias-corrected standardized mean difference (Hedges g). The hypothesis was formulated before data extraction.

RESULTS

A total of 63 studies that included 12 564 men (mean [SD] age, 55 [7] years; age range, 36-68 years) were included. Erectile function was significantly improved among participants in the placebo arm, with a small to moderate effect size (Hedges g [SE], 0.35 [0.03]; P < .001). Placebo effect size was larger among participants with ED associated with posttraumatic stress disorder (Hedges g [SE], 0.78 [0.32]; P = .02) compared with the overall analysis. No significant difference was found between placebo and PDE5Is for ED after prostate surgery or radiotherapy (Hedges g [SE], 0.30 [0.17]; P = .08).

CONCLUSIONS AND RELEVANCE

In this study, placebo was associated with improvement of ED, especially among men with ED-related posttraumatic stress disorder. No difference was found between placebo and PDE5I among men treated for ED after prostate surgery.

Significant effect of information placebo on exercise test results in children with normal weight, overweight and obesity

AIM

The aim of the study was to examine the effect of information placebo on fitness test results in normal weight, overweight and obese children.

METHODS

Twenty-four pre-pubertal children with overweight or obesity and 24 age and maturity-matched normal weight children performed a progressive treadmill exercise test twice. Different types of information were randomly provided regarding a water drink consumed prior to testing; standard (water) vs deliberate positive (presumed energy drink, placebo) information.

RESULTS

Following the placebo drink, both groups demonstrated significantly higher peak heart rate (overweight 165.8 ± 16.7 vs 174.2 ± 14.8 bpm and normal weight 177.9 ± 13.6 vs 189.8 ± 12.2 bpm) and longer time to exhaustion (overweight 396.9 ± 161.9 vs 521.5 ± 182.5 seconds; normal weight: 700.1 ± 155.2 vs 893.3 ± 150.1 seconds). Despite longer exercise duration and higher peak heart rate, average and peak rate of perceived exertion were significantly lower after the placebo drink (overweight 14.1 ± 2.5 vs 12.5 ± 2.5; normal weight 12.1 ± 1.4 vs 10.7 ± 1.5), with significantly shorter recovery time (overweight 132.2 ± 28.5 vs 118.4 ± 31.6; normal weight: 106.7 ± 18.6 vs 96.7 ± 17.8 seconds).

CONCLUSION

Our results demonstrate a significant effect of information placebo on fitness test results that is unrelated to body weight. Children with obesity may enhance their physical activity levels and energy expenditure if properly encouraged.

The effect of treatment regimens on salivary cortisol levels in patients with chronic musculoskeletal disorders

BACKGROUND

Increased levels of circulating cortisol have been associated with pain severity in patients with chronic musculoskeletal disorders (CMD). Little is known about the potential association between pain management and salivary cortisol alterations in CPM patients treated with different regimens.

OBJECTIVES

This prospective feasibility study aimed to determine the effect of two treatment regimens in comparison with sham therapy on pain intensity and disability and salivary cortisol concentration (SCC) in patients with CMD.

METHODS

Thirty patients were randomly assigned to 3 groups of 10: two experimental groups (A and B) and a control group (C). The experimental groups followed physiotherapy treatment (A) or acupuncture (B), while the control group (C) followed a sham therapy for 10 sessions. Pain data were collected using the Chronic Pain Grade (CPG) questionnaire and SCC was measured by enzyme-linked immunosorbent assay at pre- and posttreatment.

RESULTS

Repeated-measures analysis of variance showed that patients treated with acupuncture experienced greater decreases in pain intensity/pain disability (P < 0.05) than the physiotherapy and sham therapy groups. No statistical differences were found between the three groups for the SCC outcome variable. Bonferroni adjustments showed that the mean values of SCC were significantly decreased at posttreatment (P < 0.05) across the three groups.

CONCLUSION

There was a significant decrease in both pain and cortisol outcomes at posttreatment in patients with CMD. Because of the limitations of this study, we cannot draw conclusions regarding whether the lower SCC could be an indication of pain reduction in patients with CMD.

Current pharmacotherapy for gambling disorder: a systematic review

Introduction: Gambling disorder is classified as an addictive disorder and is associated with significant distress and impairment in personal, social, occupational or other important areas of functioning. Although no pharmacotherapy has a formal indication for gambling disorder, data suggest potential benefits of specific medications.Area covered: This systematic review evaluated findings from 19 randomized controlled trials testing pharmacotherapies for the treatment of gambling disorder.Expert opinion: Few randomized controlled trials have studied pharmacotherapies for gambling disorder. Though results are limited, opioid antagonists like naltrexone showed promise in the pharmacological treatment of gambling disorder. Pharmacotherapy combined with psychotherapy treatments for gambling disorder may provide better rates of patient retention in comparison to pharmacology-only treatments, though further research is needed in this area. Future studies should address gaps relating to considerations of racial, ethnic, gender and other individual differences in clinical studies. Because gambling disorder often co-occurs with other psychiatric disorders, additional research is needed to test treatments for dually diagnosed patients.

Can an Open-Label Placebo Be as Effective as a Deceptive Placebo? Methodological Considerations of a Study Protocol

Background: Placebo has been studied for many years and is ever-present in healthcare. In clinical practice, its use is limited by ethical issues raised by the deception entailed by its administration. Objective: To investigate whether, when given detailed information about pain and underlying placebo mechanisms, subjects will have a response similar to that of those subjected to a procedure in which they receive a conventional placebo treatment. Methods: The study is designed as a non-inferiority randomized, parallel with a nested crossover trial. In addition, 126 subjects without any known pathology will be included. They will be randomized into two groups. Each subject will undergo three Cold Pressor Tests (CPT): calibration, condition of interest (deceptive placebo or educated placebo), and control. Our main judgment criterion will be the comparison in pain intensity experienced on the visual analog scale between the two CPTs with placebo conditions. Results: This study will allow us to rule on the non-inferiority of an "educated" placebo compared to a deceptive placebo in the context of an acute painful stimulation. It is another step towards the understanding of open-label placebo and its use in clinical practice. Conclusions: This study has been approved by the ethics committee in France (2017-A01643-50) and registered on ClinicalTrials.gov (NCT03934138).

The placebo effect on aerobic fitness test results is preserved following a multidisciplinary intervention program for treating childhood obesity

BACKGROUND

The aim of the study was to examine the placebo effect on fitness test results in trained and untrained overweight and obese children.

METHODS

Twenty pre-pubertal overweight children performed two pairs of progressive treadmill exercise tests before and 12 weeks into a multidisciplinary program for the treatment of childhood obesity. In each test pair, at random order, participants received different types of information regarding a water drink consumed prior to testing-standard information (water) vs deliberate positive information (presumed energy drink, placebo).

RESULTS

The intervention led to a significant change (P < .05) in BMI%ile (95.6 ± 4.4 vs 93.6 ± 6.9), % fat (35.4 ± 6.0 vs 31.6 ± 5.8), baseline heart rate (104.2 ± 11.6 vs 94.0 ± 7.0 bpm), total leisure activity score-Godin (9.3 ± 8.8 vs 41.5 ± 15.2), total screen time (6.9 ± 5.8 vs 3.1 ± 1.4 h/d), and a significant improvement in fitness. Following the placebo drink, both groups achieved a significantly higher peak heart rate (untrained: 176.1 ± 13.7 vs 167.5 ± 16.8; trained: 170.7 ± 11.6 vs 166.2 ± 11.4 bpm) and longer running time (untrained: 559.9 ± 151.0 vs 434.4 ± 140.3 seconds; trained: 728.3 ± 177.3 vs 667.1 ± 176.1 seconds). Despite longer exercise duration and higher peak exercise heart rate, average, and peak RPE were lower after the placebo drink (untrained: 12.1 ± 2.3 vs 13.6 ± 2.1; trained:10.0 ± 1.8 vs 11.6 ± 2.1), recovery time was shorter (untrained: 119.2 ± 25.3 vs 133.2 ± 23.7 seconds; trained: 92.6 ± 18.9 vs 102.7 ± 18.3 seconds). The placebo-induced change in running time and peak RPE were significantly greater prior to training.

CONCLUSION

The significant information placebo effect is preserved in trained overweight children. Information, as well as other motivating aids and fatigue distractors may be useful in enhancing physical performance in obese children.

Hypnosis and communication reduce pain and anxiety in peripheral intravenous cannulation: Effect of Language and Confusion on Pain During Peripheral Intravenous Catheterization (KTHYPE), a multicentre randomised trial

BACKGROUND

Clinicians traditionally warn patients of pain before peripheral i.v. cannulation (PIVC). However, using words related to pain or undesirable experiences can result in greater pain and anxiety. The use of positive words can improve pain perception and subjective patient experience. We aimed to compare the effects of three types of communication, including hypnotic communication, on pain, comfort, and anxiety in patients during PIVC.

METHODS

The Effect of Language and Confusion on Pain During Peripheral Intravenous Catheterization (KTHYPE) trial is a randomised, parallel, single-blind, multicentre study of patients undergoing PIVC on the dorsal face of the hand before surgery. Patients from three hospitals were randomly allocated to one of three groups: PIVC performed with a hypnosis technique (hypnosis group), negative connotation (nocebo group), and neutral connotation (neutral group). The primary outcome measure was the occurrence of pain measured with a 0-10 numerical rating scale just after PIVC.

RESULTS

Of the 272 subjects analysed (hypnosis, n=89; nocebo, n=92; neutral, n=91), pain after PIVC was lower in the hypnosis group (mean [standard deviation]; range) (1.5 [1.9]; 0-5) compared with the neutral (3.5 [2.3]; 0-9; P<0.0001) and nocebo groups (3.8 [2.5]; 0-10; P<0.0001). Whilst anxiety was higher and comfort lower before PIVC in the hypnosis group, anxiety decreased and comfort perception increased after PIVC when hypnosis was used.

CONCLUSIONS

This is one of the first well-designed RCTs showing a significant benefit of a hypnosis technique during a routine procedure, such as PIVC. The results could facilitate implementation of hypnosis in daily clinical care.

CLINICAL TRIAL REGISTRATION

NCT02662322.

Between placebo and nocebo: Response to control treatment is mediated by amygdala activity and connectivity

BACKGROUND

In experimental placebo and nocebo studies, neutral control treatments are often administered for comparison with active treatments, but are of little interest, as, on average, they result in little change. Yet, when considered at an individual level, they fluctuate between baseline and subsequent measurements and may reveal important information about participants' placebo/nocebo responding tendencies.

METHODS

In a paradigm involving application of creams paired with positive, negative and neutral expectations, some subjects rated identical stimuli in the neutral condition as more painful while others as less painful after treatment with inert cream. We divided subjects into two groups based on the median split in these pre-post responses in the neutral control condition, and investigated (a) fMRI signal differences (post minus pre) between the two groups in neutral condition, and (b) seed-based resting state connectivity of the bilateral amygdala, known to be involved in emotional self-regulation, as well as ambiguous stimulus processing and aversive learning.

RESULTS

The results suggested that subjects who rated the same pain stimuli after treatment with explicitly neutral cream as more painful showed stronger fMRI activation of the amygdala during the experiment and had higher connectivity between the left amygdala and the striatum at rest. Neutral pre-post changes predicted behavioural placebo/nocebo response in this and two independent datasets.

CONCLUSION

These findings suggest that measuring pre-post change in the neutral control condition might provide important information about subjects' individual differences in placebo/nocebo response.

SIGNIFICANCE

Pre-post changes in pain ratings in neutral conditions are modulated by amygdala activity and connectivity and can be used to predict placebo/nocebo responses.

The role of the dorsolateral prefrontal cortex in the motor placebo effect

The neural correlates of the placebo effect in the motor domain are still unknown. The aim of this study was to tackle the role of a frontal cortical region, the dorsolateral prefrontal cortex (dlPFC). To this end, we stimulated the cortical site corresponding to the left dlPFC with transcranial direct current stimulation (tDCS) during a placebo procedure and measured any change in the motor placebo effect in all the participants and more specifically in placebo-responders. Three different experiments were conducted in which healthy volunteers performed a force motor task with the index finger. The placebo treatment consisted of transcutaneous electrical nerve stimulation (TENS). In Experiment 1 (expectation alone), participants were only verbally suggested about the positive effects of TENS. In Experiment 2 (expectation and conditioning), participants were verbally suggested about TENS and conditioned with a surreptitious increase in a visual feedback of force. In Experiment 3 (control procedure), participants were told that TENS was inefficient. Each participant was tested in three different days with anodal, cathodal and sham tDCS over the dlPFC. Results showed that in Experiment 1 and 2 force increased after the procedure, independently of tDCS. By focusing on placebo-responders, we found that in Experiment 1 force remained stable after active tDCS, whereas it increased after inactive tDCS. These findings bring new evidence on the neural underpinnings of the motor placebo effect, by showing that independently of the polarity, active tDCS over the left dlPFC may undermine the expectation-induced enhancement of force in placebo-responders.

Translingual Neurostimulation for the Treatment of Chronic Symptoms Due to Mild-to-Moderate Traumatic Brain Injury

OBJECTIVE

To compare the efficacy of high- and low-frequency noninvasive translingual neurostimulation (TLNS) plus targeted physical therapy (PT) for treating chronic balance and gait deficits due to mild-to-moderate traumatic brain injury (mmTBI).

DESIGN

Participants were randomized 1:1 in a 26-week double-blind phase 1/2 study (NCT02158494) with 3 consecutive treatment stages: in-clinic, at-home, and no treatment. Arms were high-frequency pulse (HFP) and low-frequency pulse (LFP) TLNS.

SETTING

TLNS plus PT training was initiated in-clinic and then continued at home.

PARTICIPANTS

Participants (N=44; 18-65y) from across the United States were randomized into the HFP and LFP (each plus PT) arms. Forty-three participants (28 women, 15 men) completed at least 1 stage of the study. Enrollment requirements included an mmTBI ≥1 year prior to screening, balance disorder due to mmTBI, a plateau in recovery with current PT, and a Sensory Organization Test (SOT) score ≥16 points below normal.

INTERVENTIONS

Participants received TLNS (HFP or LFP) plus PT for a total of 14 weeks (2 in-clinic and 12 at home), twice daily, followed by 12 weeks without treatment.

MAIN OUTCOME MEASURES

The primary endpoint was change in SOT composite score from baseline to week 14. Secondary variables (eg, Dynamic Gait Index [DGI], 6-minute walk test [6MWT]) were also collected.

RESULTS

Both arms had a significant (P<.0001) improvement in SOT scores from baseline at weeks 2, 5, 14 (primary endpoint), and 26. DGI scores had significant improvement (P<.001-.01) from baseline at the same test points; 6MWT evaluations after 2 weeks were significant. The SOT, DGI, and 6MWT scores did not significantly differ between arms at any test point. There were no treatment-related serious adverse events.

CONCLUSIONS

Both the HFP+PT and LFP+PT groups had significantly improved balance scores, and outcomes were sustained for 12 weeks after discontinuing TLNS treatment. Results between arms did not significantly differ from each other. Whether the 2 dosages are equally effective or whether improvements are because of provision of PT cannot be conclusively established at this time.

Cingulate-basal ganglia-thalamo-cortical aspects of catatonia and implications for treatment

The catatonic syndrome is an example of a multifactorial neurobehavioral disorder that causes much morbidity and mortality but also has the potential to unlock the mystery of how motivation and movement interact to produce behavior. In this chapter, an attempt is made to understand better the catatonic syndrome through the lens of neurobiology and neuropathophysiology updated by recent studies in molecular biology, genomics, inflammasomics, neuroimaging, neural network theory, and neuropsychopathology. This will result in a neurostructural model for the catatonic syndrome that centers on paralimbic regions including the anterior and midcingulate cortices, as they interface with striatal and thalamic nodes in the salience decision-making network. Examination of neurologic disorders like the abulic syndrome, which includes in its extreme catatonic form, akinetic mutism, will identify the cingulate cortex and paralimbic neighbors as regions of interest. This exploration has the potential to unlock mysteries of the brain cascade from motivation to movement and to clarify catatonia therapeutics. Such a synthesis may also help us discern meaning inherent in this complex neurobehavioral syndrome.

Treating pain in patients with dementia and the possible concomitant relief of symptoms of agitation

Dementia is an irreversible, progressive form of cognitive dysfunction that can affect memory, learning ability, thinking, orientation, comprehension, calculation, linguistic skills and executive function but which does not impair consciousness. Pain prevalence is high among the elderly who are also at elevated risk for dementia. Pain control for dementia patients is important but can be challenging for clinicians as cognitive deficits can make it difficult to identify, localize and assess pain. Cerebral changes associated with dementia may change how people process and experience pain in ways that are not entirely elucidated. Agitation is a frequent symptom of dementia and may be associated with untreated pain as agitation and aggression symptoms decrease when pain is effectively addressed.

Baseline functional connectivity may predict placebo responses to accelerated rTMS treatment in major depression

Although in theory sham repetitive transcranial magnetic stimulation (rTMS) has no inherent therapeutic value, nonetheless, such placebo stimulations may have relevant therapeutic effects in clinically depressed patients. On the other hand, antidepressant responses to sham rTMS are quite heterogeneous across individuals and its neural underpinnings have not been explored yet. The current brain imaging study aims to detect baseline neural fingerprints resulting in clinically beneficial placebo rTMS treatment responses. We collected resting‐state functional magnetic resonance imaging data prior to a registered randomized clinical trial of accelerated placebo stimulation protocol in patients documented with treatment‐resistant depression (http://clinicaltrials.gov/show/NCT01832805). In addition to global brain connectivity and rostral anterior cingulate cortex (rACC) seed‐based functional connectivity (FC), elastic‐net regression and cross‐validation procedures were used to identify baseline intrinsic brain connectivity biomarkers for sham‐rTMS responses. Placebo responses to accelerated sham rTMS were correlated with baseline global brain connectivity in the rACC/ventral medial prefrontal cortex (vmPFC). Concerning the rACC seed‐based FC analysis, the placebo response was associated positively with the precuneus/posterior cingulate (PCun/PCC) cortex and negatively with the middle frontal gyrus. Our findings provide first brain imaging evidence for placebo responses to sham stimulation being predictable from rACC rsFC profiles, especially in brain areas implicated in (re)appraisal and self‐focus processes.

Reconceptualizing the measurement of expectations to better understand placebo and nocebo effects in psychological responses to exercise

The understanding of placebo and nocebo effects in psychological responses to exercise may be improved by measuring expectations. Despite availability of several validated expectation measures, we argue for using scales that take both positive and negative expectations for exercise-induced changes into account. A cross-sectional survey was used to collect information on positive and negative expectations pertaining to how exercise would affect 14 different outcomes related to psychological health (n = 966). Outcomes for which a majority of the sample (>50%) reported positive expectations for exercise-induced changes included: psychological well-being (75.3%), depression (74.3%), relaxation (74.2%), sleep quality (73.3%), stress (72.2%), anxiety (69.8%), energy (67.1%), and attention (60.2%). Outcomes for which a majority of the sample (>50%) reported a negative expectation for exercise-induced changes were muscle pain (66.3%), fatigue (57.3%), and joint pain (50.7%). Across all 14 outcomes, the percentage of participants with negative expectations for exercise-induced changes ranged from 5.9 to 66.3%. Elucidating the potential presence of placebo and nocebo effects through measurement of expectations may improve the understanding of variability in the direction and magnitude of exercise-related effects on psychological health. Although there were only 3 outcomes for which the majority of participants reported negative expectations, we found that negative expectations were present to some degree for all 14 outcomes. Thus, for researchers who wish to characterize expectations in studies of psychological responses to exercise, we recommend using measures that give equal consideration to positive and negative expectations.

Placebo effects and the molecular biological components involved

Pharmacologically inactive substances have been used in medicine for more than 700 years and can trigger beneficial responses in the human body, which is referred to as the placebo effects or placebo responses. This effect is robust enough to influence psychosocial and physiological responses to the placebo and to active treatments in many settings, which has led to increased interest from researchers. In this article, we summarise the history of placebo, the characteristics of placebo effects and recent advancements reported from the studies on placebo effects and highlight placebome studies to identify various molecular biological components associated with placebo effects. Although placebos have a long history, the placebome concept is still in its infancy. Although behavioural, neurobiological and genetic studies have identified that molecules in the dopamine, opioid, serotonin and endocannabinoid systems might be targets of the placebo effect, placebome studies with a no-treatment control (NTC) are necessary to identify whole-genome genetic targets. Although bioinformatics analysis has identified the molecular placebome module, placebome studies with NTCs are also required to validate the related findings.

Neurobiology of placebo effect in Parkinson's disease: What we have learned and where we are going

The placebo effect is a phenomenon produced when an inert substance administered like a regular treatment improves the clinical outcome. Parkinson's disease (PD) is one of the main clinical disorders for which the placebo response rates are high. The first evidence of the neurobiological mechanisms underlying the placebo effect in PD stems from 2001, when de la Fuente-Fernandez and colleagues demonstrated that a placebo injection led to the release of dopamine in the striatal nuclei of PD measured with positron emission tomography technology. Since then, several studies have been conducted to investigate the neurobiological underpinnings of placebo responses. This article presents a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Of an initial yield of 143 papers, 19 were included. The lessons learned from these studies are threefold: (i) motor improvement is dependent on the activation of the entire nigrostriatal pathway induced by dopamine release in the dorsal striatum; (ii) the magnitude of placebo-induced effects is modulated by an expectancy of improvement, which is in turn related to the release of dopamine within the ventral striatum; (iii) the functioning of the neural pathways underlying the placebo response can be tuned by prior exposure and learning strategies. In conclusion, although the neural network underlying the placebo effect in PD has been largely confirmed and accepted, what remains to be established is how, when, and where the expectation of reward (mediated by the ventral striatum) interacts with the primary motor system (mediated by the dorsal striatum) to induce clinical improvement in motor symptoms. © 2018 International Parkinson and Movement Disorder Society.

Placebo mechanisms in depression: An experimental investigation of the impact of expectations on sadness in female participants

INTRODUCTION

We aimed to examine whether drug-associated expectations have an impact on the experience of sadness. We hypothesized that participants who received an active placebo nasal spray (but were told that it was an antidepressant that would protect them from experiencing negative emotions) would become less sad than the control groups.

METHODS

128 healthy female participants were randomly allocated to one of four groups: the experimental group, which received an active placebo and the expectancy-modifying instructions ("Protection: the spray protects from experiencing negative emotions", n = 32), or one of three different control groups ("Sensitization": the spray sensitizes to negative emotions", n = 31; "Placebo: the spray is a placebo", n = 32; and "Control: no nasal spray", n = 32) RESULTS: In line with our hypotheses, the experimental group experienced significantly less sadness after having watched a sadness provoking film sequence compared to the three control groups, with medium- to large effect sizes (Hedge´s gs 0.59-0.87).

DISCUSSION

Our results suggest that sadness can be significantly influenced by placebos in the short-term. Our study further suggests that knowledge about the effect of placebos on depressive symptoms should be utilized in clinical practice. However, depression is a complex disorder and antidepressants address a wide range of symptoms associated with depression such as suicidal thoughts, disturbed sleep and loss of energy. Further research on the placebo effects associated with the antidepressant treatment is needed.

LIMITATIONS

concern generalizability to treatment because sadness is only one potential symptom of depression and antidepressants often also address other symptoms.