The placebo puzzle: putting together the pieces

Masked Taper With Behavioral Intervention for Discontinuation of Benzodiazepine Receptor Agonists: A Randomized Clinical Trial

Importance

Placebo effects are commonly observed in benzodiazepine receptor agonist hypnotic clinical trials. Clinical guidelines recommend discontinuing benzodiazepine receptor agonist hypnotics (particularly in older adults) and administering cognitive behavioral therapy for insomnia (CBTI) as first-line therapy for insomnia. It is unknown whether a novel intervention that masks the daily dose of benzodiazepine receptor agonist during tapering and augments CBTI with novel cognitive and behavioral exercises targeting placebo effect mechanisms improves benzodiazepine receptor agonist discontinuation.

Objective

To compare a masked benzodiazepine receptor agonist taper plus augmented CBTI vs an unmasked taper plus standard CBTI.

Design, Setting, and Participants

This randomized clinical trial conducted at an academic medical center and a Department of Veterans Affairs medical center included adults aged 55 years or older who had used lorazepam, alprazolam, clonazepam, temazepam, and/or zolpidem for current or prior insomnia, at doses of less than 8-mg diazepam-equivalent 2 or more nights per week for at least 3 months. Data were collected between December 2018 and November 2023. Data analyses were conducted between November 2023 and July 2024.

Interventions

Masked taper plus cognitive behavioral therapy-augmented program (MTcap); standard CBTI plus supervised (unmasked) gradual taper (SGT).

Main Outcomes and Measures

The primary efficacy outcome was percentage achieving benzodiazepine receptor agonist discontinuation 6 months after treatment ended (6-month; intention-to-treat) measured with 7-day self-reported medication logs and for a subset, urine tests. Secondary outcomes were Insomnia Severity Index scores at 1 week posttreatment and 6 months posttreatment, percentage of participants that have discontinued benzodiazepine receptor agonist use at 1 week posttreatment, and benzodiazepine receptor agonist dose and the Dysfunctional Beliefs About Sleep-Medication subscale at 1 week and 6 months posttreatment.

Results

Of 338 participants who underwent in-depth screening, 188 participants (mean [SD] age, 69.8 [8.3] years, 123 male [65.4%] and 65 female [35.6%]) were randomly assigned to MTcap (n = 92) or SGT (n = 96). Compared with SGT, MTcap resulted in greater benzodiazepine receptor agonist discontinuation at 6 months (MTcap = 64 [73.4%], SGT = 52 [58.6%]; odds ratio [OR], 1.95; 95% CI 1.03-3.70; P = .04) and 1 week posttreatment (MTcap = 76 [88.4%], SGT =  62 [67.4%]; OR, 3.68; 95% CI, 1.67-8.12; P = .001) and reduced frequency of benzodiazepine receptor agonist use (nights/week) at 1 week posttreatment (-1.31; 95% CI, -2.05 to -0.57; P < .001). Insomnia Severity Index improved with no significant between-group difference at follow-up (baseline to 1 week posttreatment, 1.38; P = .16; baseline to 6 months, 0.16; P = .88).

Conclusions and Relevance

This randomized clinical trial found that a program combining masked tapering with novel cognitive and behavioral exercises targeting placebo mechanisms improved the percentage of long-term benzodiazepine receptor agonist discontinuation compared with standard CBTI plus an unmasked taper.

Trial Registration

ClinicalTrials.gov Identifier: NCT03687086.

Factors Predicting Nonadherence to Treatment Recommendations for Patients With Chronic Low Back Pain in India: A Cross-Sectional Survey

OBJECTIVE

The purpose of this study was to examine patients' expectations and factors that influence adherence to physiotherapists' treatment recommendations on chronic low back pain (CLBP).

METHOD

One hundred and forty seven patients with CLBP were included in this study. Predictive indicators including demographic information, views, expectations, and opinions regarding the health status and treatment expectations of patients were derived from questionnaires. The dependent outcome variables were the absence of trust in treatment recommendations provided by physiotherapists, the anticipation of treatment recommendations based on patient expectations, and the resistance to modifying expectations despite efforts by physiotherapists to persuade otherwise. The study was carried out between April 2022 and January 2023 in 2 regions located in India.

RESULTS

Multivariate regression analyses show that age, expectations about diagnosis, preference for passive therapies and medical care, and information seeking behavior emerged as independent predictors of a lack of trust in physiotherapists' treatment recommendations. The information-seeking behavior of the patients' alone predicted the anticipation of treatment recommendations based on patient expectations and the reluctance to alter those expectations despite the physiotherapists' persuasion.

CONCLUSION

Our results suggest that information seeking behavior is the most consistent independent predictor of treatment expectations that will align with physiotherapist recommendations. This indicates the importance of screening for such factors and the importance of patient education to optimize the management of CLBP. However, larger studies incorporating all variables associated with patient expectations in similar patient populations are needed to confirm these results.

Set and setting in microdosing: an oft-overlooked principle

RATIONALE

The use of psychedelics for medical and recreational purposes is rising. Contextual factors such as expectancy, intention, and sensory and social environment (set and setting) are widely recognized as moderating the effects of these substances. Nevertheless, clinical trials of microdosing - the ingestion of small, sub-hallucinogenic doses of psychedelics - rarely report their set and setting. This fact suggests that such factors are not considered important in the context of microdosing.

OBJECTIVE

This paper challenges this assumption and makes the case for the crucial relevance of set and setting in microdosing practice. Building on set and setting theory and placebo theory, we explain why set and setting are of crucial importance in the case of microdosing.

RESULTS

This reasoning helps elucidate the role of set and setting in determining the outcomes of microdosing and helps explain some of the contradictory results that have emerged in microdosing research in recent years.

CONCLUSION

Set and setting are important constructs to be considered especially in the context of microdosing psychedelics. By reporting set and setting, the results of microdosing research can be made more reliable and consistent.

Modalities of the psychedelic experience: Microclimates of set and setting in hallucinogen research and culture

Mid-20th-century American research on psychedelics evinced a stunning diversity of interpretations of hallucinogenic effects. While some researchers viewed psychedelics as invaluable tools for psychotherapy, others persisted in treating them as psychosis-inducing agents. As some groups considered psychedelics as catalysts for artistic creativity, others investigated their potential use as psychochemical weapons in the battlefield, or conversely as tools for spiritual ecstasy and revelation. This bewildering array of perceptions regarding the nature of hallucinogenic effects led to stark contrasts in the contexts (set and setting) of psychedelic research and experimentation, leading to wildly divergent outcomes and reports on the effects of the drugs, and strident disagreements between the actors in the field. Examining this remarkable historical moment of epistemological unclarity regarding psychedelics and their effects, this article describes how distinct scientific and cultural trends and moments of mid-20th-century America contributed to the creation of diverse microclimates of set and setting that reproduced investigator beliefs and attitudes and brought about a beguiling Pygmalion effect that left researchers befuddled and perplexed. I propose the concept of psychedelic modality to describe how distinct sociocultural microclimates lead to thematic aggregates in which distinct types of expectations, intentions as well as physical, social, and cultural environments all tend to cluster, producing characteristic outcomes and results. By exploring the historical context and consequences of the emergence of seven psychedelic modalities (psychotomimetic, military, psychotherapeutic, spiritual, artistic-creative, tech-innovative, and political) in mid-20th-century America, this article outlines the varieties of psychedelic experiences in their relationship with culture at large, and subcultures in particular.

Perceived Consumption of a High-Dose Caffeine Drink Delays Neuromuscular Fatigue

ABSTRACT

Elhaj, HM, Imam, O, Page, BW, Vitale, JM, and Malek, MH. Perceived consumption of a high-dose caffeine drink delays neuromuscular fatigue. J Strength Cond Res 36(5): 1185-1190, 2022-The placebo effect is a concept in which a desired outcome arises, mainly from the belief that the treatment (i.e., supplement or drug) was beneficial although no active ingredient was given. The results of studies related to the placebo effect primarily examine functional performance. What remains unanswered, however, is whether these changes in performance are associated with neuromuscular alterations in the exercised muscles. The purpose of the study, therefore, was to determine the influence of the placebo effect on the physical working capacity fatigue threshold (PWCFT) for a continuous exercise paradigm. To achieve this aim, subjects were told that they were participating in a study to determine the dosage response (low or high) of caffeine on neuromuscular fatigue when in fact no caffeine was given during the experiment. We hypothesized that the perceived consumption of the high-dose caffeine drink would result in a higher PWCFT than the perceived consumption of the low-dose caffeine drink and placebo. Secondarily, we hypothesized that the perceived consumption of the high-dose caffeine drink would result in a higher power output than the perceived consumption of the placebo. Nine healthy college-aged men (mean ± SEM: age, 25.7 ± 1.3 years; body mass, 84.4 ± 3.1 kg; and height: 1.82 ± 0.02 m) volunteered to be in the study. For each of the visits, subjects were given an 8 oz. bottle of water with dissolved crystal light. After the drink was consumed, subjects rested in the laboratory for 1 hour before performing the incremental single-leg knee-extensor ergometry. Immediately after the termination of the incremental single-leg knee-extensor ergometry, the subject was asked which caffeine dose (placebo, low, or high) they believed they consumed for that visit. There were no significant mean differences for maximal power output for the 3 perceived conditions (placebo: 62 ± 3, low-dose caffeine: 62 ± 4, and high-dose caffeine: 65 ± 3 W). When the subjects perceived consuming the high-dose caffeine drink, there were significant mean differences (all p-values < 0.01), for PWCFT, between the other conditions (mean ± SEM: placebo: 23 ± 3 W, low-dose caffeine: 26 ± 2 W, and high-dose caffeine: 42 ± 3 W). This corresponded to a significant mean difference (all p-values < 0.01) when the PWCFT was presented as a percentage of the maximal power output (mean ± SEM: placebo: 37 ± 5%, low-dose caffeine: 42 ± 3%, and high-dose caffeine: 64 ± 3%). The application of our results may indicate that the subject's expectancy, to caffeine consumption, plays a critical role in delaying the onset of neuromuscular fatigue despite not receiving any caffeine in their drinks.

Set and Setting in the Santo Daime

Set and setting is a fundamental concept in the field of psychedelic drug research, which points to the profound dependence of psychedelic effects on psychological, social, and cultural factors. Santo Daime is a Brazilian religion that makes elaborate use of ordering principles, techniques, and symbology to shape and direct the effects of the hallucinogenic brew ayahuasca. This paper systematically explores the tapestry of, inter alia, symbolic, social, cultural, psychological, aesthetic and musical elements that participate in the shaping of the psychedelic experience in the context of the Santo Daime ayahuasca religion. The methodically rich under the hood description of the mechanics of entheogenic initiation within the Santo Daime tradition provides a template for future studies of the role of context in psychedelic experimentation.

Experimentally-manipulated perceptions of good sleep predict greater reactivity to and poorer recovery from a social stressor in university students

OBJECTIVE

The present study was conducted to examine the impact of experimentally-manipulated perceptions of sleep on self-reported affective reactivity and recovery from a social stressor in undergraduate students.

DESIGN

The study design is experimental, as the participants were randomly assigned to either good or poor perceived sleep quality conditions.

MAIN OUTCOME MEASURES

The impact of condition on self-reported affective responses to and recovery from the social stressor were assessed as well as whether the observed effects were moderated by stress, rumination, and depression.

RESULTS

Participants in the good sleep condition reported increased negative affect (NA) after the social stressor and after a six-minute recovery period relative to participants in the poor sleep condition; participants in the former condition also reported heightened NA post-recovery relative to baseline (a comparison that was non-significant for participants in the poor sleep condition). The effect of condition on NA post-stressor and post-recovery was moderated by depression and rumination, with important implications for participants in the good sleep condition in particular.

CONCLUSIONS

These findings may have resulted from participant expectations about the impacts of sleep on their behaviour, although additional research remains to be conducted to identify the mechanism responsible for the obtained pattern of results.

Linking coping strategies to locally-perceived aetiologies of mental distress in northern Rwanda

INTRODUCTION

How and why people in a particular setting turn to a specific coping strategy for their distress is pivotal for strengthening mental healthcare and this needs to be understood from a local point of view. Prior research in northern Rwanda documented common local concepts of distress for the population that cannot receive assistance despite severe adversities; however, the locally-perceived causes, manifestation and coping strategies and their associations are still unclear.

METHODS

The qualitative study in the Musanze district, northern Rwanda, was informed by Interpretative Phenomenological Analysis. In-depth interviews were conducted with people with lived experience and those in close contact with people with lived experience of distress. Ethnographic observation was conducted and the analyses were complimented by an earlier ethnography in the same village.

RESULTS

Study participants (n=15) included community members with lived experience of mental distress and/or those with close friends or family with lived experience. The perceived manifestations of the mental distresses were diverse and the causal attributions shifted from more social, concrete and explainable (eg, loss) towards magical, more abstract and unexplainable (eg, poisoning). Finally, participants sought coping strategies in accordance with their causal attribution in ways that made sense to them.

CONCLUSION

The coping strategies were chosen according to the perceived aetiology of the symptoms and they were perceived to be effective for their distress. Local coping strategies that match people's help-seeking patterns should therefore be supported in policy and programmes. In Rwanda this requires a mutual training of medical professionals and traditional healers and establishing co-treatment within two parallel systems. This also requires the support for programmes and initiatives that strengthen positive interactions and change in circumstances.

Considerations and methods for placebo controls in surgical trials (ASPIRE guidelines)

Placebo comparisons are increasingly being considered for randomised trials assessing the efficacy of surgical interventions. The aim of this Review is to provide a summary of knowledge on placebo controls in surgical trials. A placebo control is a complex type of comparison group in the surgical setting and, although powerful, presents many challenges. This Review outlines what a placebo control entails and present understanding of this tool in the context of surgery. We consider when placebo controls in surgery are acceptable (and when they are desirable) in terms of ethical arguments and regulatory requirements, how a placebo control should be designed, how to identify and mitigate risk for participants in these trials, and how such trials should be done and interpreted. Use of placebo controls is justified in randomised controlled trials of surgical interventions provided there is a strong scientific and ethical rationale. Surgical placebos might be most appropriate when there is poor evidence for the efficacy of the procedure and a justified concern that results of a trial would be associated with high risk of bias, particularly because of the placebo effect. Feasibility work is recommended to optimise the design and implementation of randomised controlled trials. This Review forms an outline for best practice and provides guidance, in the form of the Applying Surgical Placebo in Randomised Evaluations (known as ASPIRE) checklist, for those considering the use of a placebo control in a surgical randomised controlled trial.

Choice, Expectations, and the Placebo Effect for Sleep Difficulty

BACKGROUND

Choice has been found to facilitate placebo effects for single-session treatments where standard placebo treatment without choice failed to elicit a placebo effect. However, it is unknown whether choice can enhance the placebo effect for treatments occurring over a period of days and where placebo effects are readily established without choice.

PURPOSE

We tested whether single or daily choice between two (placebo) treatments enhanced the placebo effect for sleep difficulty relative to no choice and no treatment over a 1 week period.

METHODS

One-hundred and seventeen volunteers self-identifying with sleep difficulty were recruited under the guise of a hypnotic trial and randomized to one of the four groups. Self-reported outcomes included insomnia severity, fatigue, total sleep time (TST), sleep onset latency (SOL), perceived sleep quality (PSQ), and treatment satisfaction. Objective TST and SOL were assessed in a subsample via actigraphy.

RESULTS

Overall, placebo treatment significantly improved insomnia severity, fatigue, and PSQ, confirming a placebo effect on these outcomes. However, both traditional and Bayesian analysis indicated no benefit of choice on the placebo effect on any sleep outcome. Mediation analysis of the overall placebo effect indicated that expectancy completely mediated the placebo effects for insomnia severity and PSQ and partially mediated the placebo effect for fatigue.

CONCLUSION

These findings suggest that choice does not enhance the placebo effect over longer treatment periods (up to 7 days) when placebo effects are readily established without choice. As such, any benefit of choice on placebo effects may be confined to quite specific circumstances.

CLINICAL TRIALS REGISTRATION

ACTRN12618001199202.

Deceptive but not open label placebos attenuate motion-induced nausea

OBJECTIVE

Nausea is a common complaint, known to respond to the placebo effect. Existing research has employed deception when administering placebos for nausea, limiting therapeutic translation on ethical grounds. We therefore examined the potential of non-deceptive open-label placebos (OLPs) to reduce nausea.

METHODS

Galvanic Vestibular Stimulation (GVS) and Virtual Reality (VR) were employed to model nausea in healthy volunteers across two experiments. In both experiments nausea was elicited with and without sham treatment (peppermint vapor and brain stimulation, respectively). In Exp. 1, participants (n = 61) were randomized to deceptive placebo, semi-open placebo, fully-open placebo, or control. In Exp. 2, participants (n = 93) were randomized to deceptive placebo, semi-open placebo, or control.

RESULTS

Exp. 1 found limited evidence for a placebo effect (F(1, 56) = 1.15, p = .29, η_p² =0.02), even following deceptive treatment (F(1, 56) = 1.92, p = .17, η_p²=0.03). In Exp. 2, deceptive placebo reduced nausea relative to control (F(1, 89) = 6.91, p = .010, η_p²=0.07) and OLP (F(1, 89) = 5.47, p = .022, η_p²=0.06). Pooled Bayesian analysis across experiments provided strong evidence that deceptive placebos reduce nausea relative to control (BF₁₀ = 30.91) and anecdotal evidence for the benefit of deceptive treatment over non-deceptive (BF₁₀ = 2.46) and no benefit of OLP over control (BF₁₀ = 0.63).

CONCLUSIONS

No positive evidence for OLP effects in nausea were observed. However, a deceptive effect in VR was observed. These findings raise questions regarding the efficacy of open-label intervention in nausea.

Super Pill is Less Effective than an Ordinary Mint in Altering Subjective Psychological Feeling States within a Few Minutes

Expectations shape human behavior. Initial drug use might be associated with information-based expectations. In this study, we presumed that changes in affect and perceived physical wellbeing will be stronger after receiving an active placebo (Tic Tac mint; n = 40), than a pure placebo (inert pill; n = 40) given as a mood-enhancing "super pill." After baseline measures, participants completed a treatment-expectancy scale, ingested the mint/super pill, and attended to the effects over 3-minutes. Subsequently, they completed again the psychological tests. Expectancy scores were positive and did not differ between the groups. The pure placebo group increased in physical wellbeing but less than the active placebo group, which also showed an increase in positive affect. Negative affect decreased in both groups. The Tic Tac produced greater affective changes than the pure placebo. Since these are new findings on the ultra-short placebo effects on affect, the results might have relevance for drug-use studies.

Rethinking placebo in psychiatry: how and why placebo effects occur

This article outlines proximate (physical and mental) and ultimate mechanisms of placebo effects. Interpersonal processes contributing to placebo effects are reviewed and illustrated through research into the process of psychotherapy. Evolutionary theories of how and why the capacity for placebo effects might have evolved are described. The components of treatment and placebo effects are defined. It is concluded that maximising therapeutic placebo effects is effective and a valid clinical goal.

The effect of changes in pain expectations on persistent pain following a road traffic crash

BACKGROUND

Recovery expectations can influence outcomes after injury, but little is known about the course of expectations over time or factors predicting changes in expectations. This study aimed to describe how expectations of persistent pain change over time following a non-catastrophic injury sustained in a road traffic crash (RTC); identify the early predictors of change in expectations over time; and examine whether change in expectations predicted pain at 24 months post-RTC.

METHODS

One hundred and seventy-seven participants (Mage = 49.25; SD = 14.15; 66.1% female) reported their expectations of persistent pain (1 = no risk that pain will become persistent, 10 = highest risk) at approximately 6, 12 and 24 months post-injury via survey. Measures of pain, emotional distress, post-traumatic stress, fear avoidance beliefs, social support and quality of life were also measured via survey at each time point.

RESULTS

Cluster analysis revealed four clusters: 42% of participants showed a pattern of stable expectations (stable high-risk, n = 74), whereas 58% of participants showed changes in expectations over time (decreasing risk, n = 31; increasing risk, n = 44; risk peaking at 12 months, n = 28). Hierarchical linear regression models demonstrated that the clusters were a better statistical predictor of pain at 24 months than a single measure of expectation taken at 6 months post-injury. Pain, anxiety, depression and physical health-related quality of life at 6 months were associated with cluster affiliation.

CONCLUSIONS

Assessment of patterns of pain expectancy change is a superior means of determining long-term pain levels. Understanding expectancy change patterns will help provide more nuanced targets for pain intervention.

SIGNIFICANCE

This study extends previous work by investigating persistent pain expectancies over time in a compensation-seeking cohort with non-catastrophic injuries. It identifies factors that are associated with changing expectations, providing targets for clinical intervention. The study shows that expectations can change over time. Conversations with patients about their expectations should be ongoing.

Set and setting, psychedelics and the placebo response: An extra-pharmacological perspective on psychopharmacology

Placebo response theory and set and setting theory are two fields which examine how non-biological factors shape the response to therapy. Both consider factors such as expectancy, preparation and beliefs to be crucial for understanding the extra-pharmacological processes which shape the response to drugs. Yet there are also fundamental differences between the two theories. Set and setting concerns itself with response to psychoactive drugs only; placebo theory relates to all therapeutic interventions. Placebo theory is aimed at medical professionals; set and setting theory is aimed at professionals and drug users alike. Placebo theory is primarily descriptive, describing how placebo acts; set and setting theory is primarily prescriptive, educating therapists and users on how to control and optimize the effects of drugs. This paper examines how placebo theory and set and setting theory can complement and benefit each other, broadening our understanding of how non-biological factors shape response to drugs and other treatment interventions.

Physical Recovery after Acute Myocardial Infarction: Positive Age Self-Stereotypes as a Resource

We considered whether positive and stable self-stereotypes of stigmatized group members can influence functioning (in contrast, stereotype threat theory suggests these influential self-stereotypes are limited to ones that are negative and situational). Specifically, we examined older individuals' positive age stereotypes after a life-threatening event, an acute myocardial infarction (AMI). Sixty-two persons, aged 50 to 96, participated. As expected, positive age stereotypes were found, even immediately after an AMI, and they did not significantly change over the next seven months. Also as expected, these self-stereotypes predicted physical recovery, after adjusting for potentially relevant covariates. Recovery expectations acted as a mediator. These findings suggest the importance of understanding the role that positive stereotypes may play in the health of stigmatized group members.

Placebo/Nocebo Symptom Reporting in a Sham Herbal Supplement Trial

The present study examined reports of placebo and nocebo symptoms in a college sample. The study was presented under the guise of a clinical trial to evaluate the effectiveness of an over-the-counter herbal supplement intended to enhance cognitive performance. Participants were informed they would be receiving either an herbal supplement or a placebo, and each was provided with a mock list of possible beneficial and adverse effects of the “supplement.” In fact, all participants received placebo. Symptoms were endorsed by a significant majority of participants following placebo ingestion. More important, results indicated that the few participants who believed they received an herbal supplement endorsed (via self-report) significantly more symptoms than those who believed they received a placebo. Neither anxiety nor social desirability was significantly related to symptom reporting. Results suggest that beliefs concerning treatment received may subsequently affect the degree of placebo response in a no-treatment group. Implications for clinical trials and future research are discussed.

Affect and exercise: positive affective expectations can increase post-exercise mood and exercise intentions

BACKGROUND

Prior research has found affect to predict exercise. Little research has examined the causal influence of exercise-related affect on exercise intentions.

PURPOSE

The purpose of this study was to test whether expectations about post-exercise affect can be successfully manipulated to produce changes in post-exercise affect and exercise intentions. We also tested whether cognitively elaborating on the expectation would increase the duration of the expectation effect.

METHODS

Participants (59 men, 89 women) were exposed to an affective expectation manipulation as well as an elaboration manipulation and then completed 10 min of light-intensity exercise on a stationary bicycle in the laboratory. Participants also completed a 2-week follow-up.

RESULTS

Affective expectation participants displayed more positive post-exercise affect and exercise intentions than no-expectation participants (ps < .05). Affective expectation participants who also elaborated on that expectation reported more positive post-exercise affect during the follow-up than the no-elaboration participants (p < .05).

CONCLUSION

Expectations about positive post-exercise affect can be experimentally manipulated to increase exercise-related feelings and intentions. The duration of this effect increases when individuals cognitively elaborate on the expectation.

Understanding and translating the knowledge about placebo effects: the contribution of psychology

PURPOSE OF REVIEW

Recent articles have summarized the literature on the neurobiological mechanisms involved in placebo effects. In this article, we review and evaluate the status of the psychological mechanisms in theory and research regarding placebo effects.

RECENT FINDINGS

Currently, the placebo effect literature concentrates more on neurobiological mechanisms than on psychological mechanisms. Both theoretical and empirical coverage of the psychological mechanisms are typically limited to two variables: conditioning and verbally induced expectations. Because psychological processes take center stage in mediating the link between the therapeutic context and placebo responding, greater effort is needed to build empirically derived and theoretically complex psychological process models. Such models would include a broader array of psychological constructs and mechanisms.

SUMMARY

Research and theory on placebo effects has illuminated much regarding the neurobiological mechanisms. The psychological mechanisms, however, have received much less attention. Expanding our knowledge regarding the psychological processes involved in placebo responding would open up opportunities for developing nondeceptive intervention techniques that encourage placebo responses. Ultimately, a concerted empirical effort to clarify the psychological model underlying placebo effects could merge with the evolving neurobiological model to fulfill the promise that placebo effects have for improving patient outcomes.

The placebo effect, sleep difficulty, and side effects: a balanced placebo model

Medical treatment is usually accompanied by a warning about potential side effects. While constituting an important component of informed consent, these warnings may themselves contribute to side effects via the placebo effect. We tested this possibility using a 2 × 2 between-subjects design. Under the guise of a trial of a new hypnotic, 91 undergraduates experiencing difficulty sleeping were allocated to receive a warning about a target side effect (either increase or decrease in appetite, counterbalanced) or no warning and then to receive placebo treatment or no treatment for one week. Placebo treatment led to significantly better sleep on almost all self-reported outcomes, suggesting a placebo effect for reported sleep difficulty. Actigraphy recordings were unaffected by treatment. There was a clear effect of the warning in that placebo treated participants who were warned about side effects were much more likely to report the target side effect than those not warned about side effects. Implications for clinical practice are discussed.

Influence of negative stereotypes and beliefs on neuropsychological test performance in a traumatic brain injury population

The impact of stereotype threat and self-efficacy beliefs on neuropsychological test performance in a clinical traumatic brain injury (TBI) population was investigated. A total of 42 individuals with mild-to-moderate TBI and 42 (age-, gender-, educationally matched) healthy adults were recruited. The study consisted of a 2 (Type of injury: control, TBI) × 2 (Threat Condition: reduced threat, heightened threat) between-participants design. The purpose of the reduced threat condition was to reduce negative stereotyped beliefs regarding cognitive effects of TBI and to emphasize personal control over cognition. The heightened threat condition consisted of an opposing view. Main effects included greater anxiety, motivation, and dejection but reduced memory self-efficacy for head-injured-groups, compared to control groups. On neuropsychological testing, the TBI-heightened-threat-group displayed lower scores on Initial Encoding (initial recall) and trended toward displaying lower scores on Attention (working memory) compared to the TBI-reduced-threat-group. No effect was found for Delayed Recall measures. Memory self-efficacy mediated the relation between threat condition and neuropsychological performance, indicating a potential mechanism for the threat effect. The findings highlight the impact of stereotype threat and self-referent beliefs on neuropsychological test performance in a clinical TBI population.

How do low back pain patients conceptualize their expectations regarding treatment? Content analysis of interviews

PURPOSE

The purpose of this study was to gain insight into how low back pain (LBP) patients conceptualize the construct of expectations regarding treatment.

METHODS

This study was nested within a mixed-method randomized clinical trial comparing three primary care interventions for LBP. A total of 77 participants with LBP lasting longer than 6 weeks were included; semi-structured interviews were conducted querying patients about their expectations for treatment. Also factors influencing their expectations were explored. Interviews were administered following enrollment into the study, but prior to study treatment. Two researchers independently conducted a content analysis using NVIVO 9 software.

RESULTS

LBP patients' expectations could be categorized in two main domains: outcome and process expectations, each with subdomains. Patients expressed expectations in all subdomains both as values (what they hoped) and probabilities (what they thought was likely). In multiple subdomains, there were differences in the nature (positive vs. negative) and frequency of value and probability expectations. Participants reported that multiple factors influenced their expectations of which past experience with treatment appeared to be of major influence on probability expectations.

CONCLUSION AND RECOMMENDATIONS

This study showed that LBP patients' expectations for treatment are multifaceted. Current measurement instruments do not cover all domains and subdomains of expectations. Therefore, we recommend the development of new or improved measures that make a distinction between value and probability expectations and assess process and/or outcome expectations covering multiple subdomains. Some of the influencing factors found in this study may be useful targets for altering patients' treatment expectations and improving health outcomes.

Expectation and the placebo effect in inflammatory skin reactions: a randomised-controlled trial

OBJECTIVE

This study investigated the placebo effect on experimentally induced skin reactions via the manipulation of expectation.

METHODS

Fifty-eight healthy volunteers were randomised into either expectancy or control groups. All participants received a baseline administration of histamine on one arm (Time 1), then a second administration on the other arm, approximately 30 minutes later (Time 2). Prior to the second administration, the expectancy group was told that an antihistamine cream (the placebo) had been applied that would reduce their skin reaction to the histamine. Expected wheal area, actual wheal area, heart rate, and heart rate variability were measured at each time point.

RESULTS

There was a positive relationship between expected and actual wheal area at Time 1. While the expectancy group expected a smaller skin reaction on the second arm they did not experience a greater reduction in wheal area, compared to control. The expectancy group had a greater reduction in heart rate during the second skin reaction, after the manipulation of expectation (p<.05).

CONCLUSION

While wheal area was not modulated, it may be worth further investigating this possibility, with modifications to the protocol. The reduction of heart rate appears to be an expectation effect and future research could elucidate mechanisms involved. There is an indication that expectations and inflammatory skin reactions are associated. Further study might aim to clarify the direction and nature of this relationship.

The effect of an apparent change to a branded or generic medication on drug effectiveness and side effects

OBJECTIVE

Generic medications are associated with reduced perceived effectiveness, increased perceived adverse effects, and increased rates of nonadherence compared with brand-name medications. This study examined the effect of an apparent medication formulation change on subjective and objective measures of medication effectiveness and medication side effects.

METHODS

Sixty-two university students participated in a study purportedly testing the effectiveness of fast-acting β-blocker medications in reducing preexamination anxiety. All tablets were placebos. In session 1, all participants received a yellow tablet ("Betaprol"). In session 2, participants were randomly allocated to receive Betaprol (no change condition) or a white tablet labeled either as "Novaprol" (branded change condition) or "Generic" (generic change condition). Blood pressure and state anxiety were measured before and after tablet ingestion. Side effects attributed to medication were assessed.

RESULTS

The no change group showed significantly greater decreases in systolic blood pressure (mean [M] [standard deviation] = -7.72 mm Hg, standard error [SE] = 1.45) than the branded change (M = -2.75 mm Hg, SE = 1.44, p = .02) and generic change (M = -3.26 mm Hg, SE = 1.45, p = .03) groups. The no-change group showed significantly greater decreases in state anxiety (M = -1.53, SE = 0.33) than the branded change (M = -0.50, SE = 0.33, p = .03) and generic change (M = -0.52, SE = 0.33, p = .04) groups. Significantly more side effects were attributed to the medication in the generic change (M = 1.83, SE = 0.23) (but not the branded change) condition when compared with the no change condition (M = 0.87, SE = 0.31, p = .03).

CONCLUSIONS

Medication formulation change, particularly to generic medication, seems to be associated with reduced subjective and objective measures of medication effectiveness and increased side effects.

Warning about side effects can increase their occurrence: an experimental model using placebo treatment for sleep difficulty

Patients in clinical practice and participants in clinical trials are warned about side effects that may result from their treatment. Such warnings could lead to placebo-induced side effects if they create an expectation of these effects. We used an experimental model to test this possibility. Undergraduates reporting sleep difficulty received placebo treatment disguised as a hypnotic for one week and were warned about either one or four bogus side effects. Placebo treatment significantly improved sleep difficulty relative to a no treatment control group, as indicated by self-report and by objective outcomes. At the end of the treatment week participants who had been warned about a single side effect showed better recall of this effect than those warned about four side effects. Most importantly, participants tended to report experiencing a side effect they had been warned about, with a trend towards a larger effect in participants warned about one side effect. This evidence for placebo-induced side effects may need to be considered when interpreting data on side effects from clinical trials.

The placebo in the context of scientific theories

Placebo is not a unitary concept. It can have different meanings, depending on the scientific discipline in which it is used. The placebo exists in psychology, medicine, and other sciences, and in each case it is assumed that the results obtained by the placebo are unexplainable. But the results that can’t be explained by a scientific discipline could be explained by another. For example, a sugar pill used in the treatment of pain could be a pharmacological placebo, but it isn’t a psychological placebo, because there is an explanation of its effects based in psychological principles. In this work, a conceptual analysis of placebo in the context of scientific theories is presented.

A pilot study of qigong practice and upper respiratory illness in elite swimmers

Upper respiratory tract infections (URIs) are a common complaint in competitive swimmers and can adversely affect performance. No intervention has yet been shown to reduce URI incidence in intensively trained athletes. The University of Virginia varsity swim team received three weeks of training in qigong for the purpose of reducing stress and improving health. Our primary objective was to assess the relationship between qigong practice and symptoms of URI during a time when swimmers would be at high URI risk. Secondary objectives were to assess degree of compliance with a qigong practice regimen, to evaluate differences between qigong practitioners and non-practitioners, and to determine the response-rate and reliability of a newly developed internet-based, self-report survey. The design was observational, cross-sectional, and prospective. Weekly data on cold and flu symptoms, concurrent health problems and medication use, and qigong practice were gathered for seven weeks. Retrospective information on health and qigong training response was also collected. Participants were 27 of the 55 members of the University of Virginia Swim Team in the Virginia Athletic Department. Main outcomes were measures of aggregated cold/flu symptoms and Qigong practice. Survey completion was 100%, with no missing data, and reliability of the instrument was acceptable. Cold and flu symptoms showed a significant non-linear association with frequency of qigong practice (R(2) = 0.33, p < 0.01), with a strong, inverse relationship between practice frequency and symptom scores in swimmers who practised qigong at least once per week (R(2) = 0.70, p < 0.01). Qigong practitioners did not differ from non-practitioners in demographic or lifestyle characteristics, medical history, supplement or medication use, or belief in qigong. These preliminary findings suggest that qigong practice may be protective against URIs among elite swimmers who practice at least once per week.

Spirituality: an overlooked predictor of placebo effects?

Empirical findings have identified spirituality as a potential health resource. Whereas older research has associated such effects with the social component of religion, newer conceptualizations propose that spiritual experiences and the intrapersonal effects that are facilitated by regular spiritual practice might be pivotal to understanding potential salutogenesis. Ongoing studies suggest that spiritual experiences and practices involve a variety of neural systems that may facilitate neural 'top-down' effects that are comparable if not identical to those engaged in placebo responses. As meaningfulness seems to be both a hallmark of spirituality and placebo reactions, it may be regarded as an overarching psychological concept that is important to engaging and facilitating psychophysiological mechanisms that are involved in health-related effects. Empirical evidence suggests that spirituality may under certain conditions be a predictor of placebo response and effects. Assessment of patients' spirituality and making use of various resources to accommodate patients' spiritual needs reflect our most current understanding of the physiological, psychological and socio-cultural aspects of spirituality, and may also increase the likelihood of eliciting self-healing processes. We advocate the position that a research agenda addressing responses and effects of both placebo and spirituality could therefore be (i) synergistic, (ii) valuable to each phenomenon on its own, and (iii) contributory to an extended placebo paradigm that is centred around the concept of meaningfulness.

Placebo response in clinical trials with schizophrenia patients

PURPOSE OF REVIEW

The magnitude of placebo response is an important factor in the outcome of clinical trials, in that excessive placebo response can obscure true drug-placebo differences. There is ample evidence of the impact of elevated placebo response in trials of major depression, but less intensive research has been done in the area of schizophrenia. We present a current review of placebo response in clinical trials of schizophrenia.

RECENT FINDINGS

The existing evidence suggests that placebo response in schizophrenia trials may be similar in magnitude, quality, and impact to that observed in depression trials, and has similarly increased over the past several years. We discuss factors influencing excessive placebo response during the conduct of clinical trials and how they may be managed to help minimize placebo response.

SUMMARY

There does not appear to be any single major factor contributing to the high levels of placebo response in schizophrenia clinical trials; therefore, a multipronged approach to minimizing excessive placebo response or its impact is recommended.

Behavior and symptom change among women treated with placebo for sexual dysfunction

INTRODUCTION

In clinical trials of drug treatments for women's sexual dysfunction, placebo responses have often been substantial. However, little is known about the clinical significance, specificity, predictors, and potential mechanisms of placebo response in sexual dysfunction.

AIM

We aimed to determine the nature and predictors of sexual function outcomes in women treated with placebo for female sexual arousal disorder (FSAD).

METHODS

We conducted a secondary analysis of data from the placebo arm of a 12-week, multisite, randomized controlled pharmaceutical trial for FSAD (N=50). We analyzed the magnitude, domain specificity, and clinical significance of sexual function scores at baseline, 4, 8, and 12 weeks (post-treatment). We examined longitudinal change in sexual function outcomes as a function of several baseline variables (e.g., age, symptom-related distress) and in relation to changes in sexual behavior frequency during the trial.

MAIN OUTCOME MEASURE

Female Sexual Function Index total score.

RESULTS

The magnitude of change at post-treatment was clinically significant in approximately one-third of placebo recipients. Effect sizes were similar across multiple aspects of sexual function. Symptom improvement was strongly related to the frequency of satisfying sexual encounters during treatment. However, the relationship between sexual encounter frequency and outcome varied significantly between participants.

CONCLUSIONS

A substantial number of women experienced clinically significant improvement in sexual function during treatment with placebo. Changes in sexual behavior during the trial, more so than participant age or symptom severity at baseline, appeared to be an important determinant of outcome. Contextual and procedural aspects of the clinical trial may have influenced outcomes in the absence of an active drug treatment.

An exploratory study on the effects of an expectancy manipulation on chemotherapy-related nausea

CONTEXT

Previous research has shown that the effectiveness of acupressure bands in reducing chemotherapy-related nausea is related to patients' expectations of efficacy.

OBJECTIVE

To test whether an informational manipulation designed to increase expectation of efficacy regarding acupressure bands would enhance their effectiveness.

METHODS

We conducted an exploratory, four-arm, randomized clinical trial in breast cancer patients about to begin chemotherapy. All patients received acupressure bands and a relaxation CD. This report focuses on Arm 1(expectancy-neutral informational handout and CD) compared with Arm 4 (expectancy-enhancing handout and CD). Randomization was stratified according to the patient's level of certainty that she would have treatment-induced nausea (two levels: high and low). Experience of nausea and use of antiemetics were assessed with a five-day diary.

RESULTS

Our expectancy-enhancing manipulation resulted in improved control of nausea in the 26 patients with high nausea expectancies but lessened control of nausea in 27 patients having low nausea expectancies. This interaction effect (between expected nausea and intervention effectiveness) approached statistical significance for our analysis of average nausea (P=0.084) and reached statistical significance for our analysis of peak nausea (P=0.030). Patients receiving the expectancy-enhancing manipulation took fewer antiemetic pills outside the clinic (mean(enhanced)=12.6; mean(neutral)=18.5, P=0.003).

CONCLUSION

This exploratory intervention reduced antiemetic use overall and also reduced nausea in patients who had high levels of expected nausea. Interestingly, it increased nausea in patients who had low expectancies for nausea. Confirmatory research is warranted.

Biological, clinical, and ethical advances of placebo effects

For many years, placebos have been defined by their inert content and their use as controls in clinical trials and treatments in clinical practice. Recent research shows that placebo effects are genuine psychobiological events attributable to the overall therapeutic context, and that these effects can be robust in both laboratory and clinical settings. There is also evidence that placebo effects can exist in clinical practice, even if no placebo is given. Further promotion and integration of laboratory and clinical research will allow advances in the ethical use of placebo mechanisms that are inherent in routine clinical care, and encourage the use of treatments that stimulate placebo effects.

Would the elderly be better off if they were given more placebos?

Placebos are useful in the medical care of the elderly, although the exact definition of a "placebo" or "placebo effect" is difficult to define precisely. They have an important role as control treatments in research trials, but a non-specific "placebo effect" may also be beneficial part of many physician-patient interactions. Physicians also give them deliberately according to several studies worldwide to satisfy patient demands or because they believe in a "placebo effect" among other reasons. A significant placebo effect has been observed among older patients in clinical trials of antidepressants (12-15%), and in treatments of Parkinson's disease (16%). Placebos activate serotonergic pathways in the brain used by antidepressants. In Parkinson's disease, the administration of a placebo stimulates dopamine release in the dorsal (resulting in motor effects) and ventral striatum (which influences expectation of reward). Much of our understanding of the placebo effect comes from studies of placebo analgesia which is influenced by conditioning, expectation, meaning and context of the treatment for the patient, and patient-physician interaction. It is anatomically medicated by brain opioid pathways. Response to "sham" acupuncture in osteoarthritis may be an example of its use in the elderly. Placebos have often been considered a deception and thus unethical. On the other hand, some physicians and ethicists have suggested conditions for appropriate uses for placebos. A placebo might offer the theoretical advantage of an inexpensive treatment that would not cause adverse drug reactions or interactions with other medications, potentially avoiding complications of polypharmacy.

Lay and professional expectations of cholinesterase inhibitor treatment in the early stage of Alzheimer's disease

The objectives of the study were to identify, compare and contrast the expectations of key stakeholders regarding cholinesterase inhibitor treatments prescribed to people with Alzheimer's Disease (AD), and to examine those expectations in the light of recent findings regarding the efficacy and effectiveness of this class of drug. Participants were four older women diagnosed with early stage AD, their lay caregivers, their professional healthcare providers, and pharmacists and policy makers, making a total of 23 participants. Semi-structured interviews were performed in a conversational style designed to elicit accounts of expectations of cholinesterase inhibitors in relation to diagnosis and treatment for AD. The interviews were carried out in the participants' own homes, their places of work or by telephone. A five-member, multidisciplinary team taped, transcribed and coded the interviews using qualitative software in order to identify overarching themes.

The study found that although the policy makers and physicians harbored more skeptical or negative expectations, the majority of stakeholders expected that people diagnosed with AD would reap beneficial effects through the use of cholinesterase inhibitors. The study concludes that there is still controversy about the use of cholinesterase inhibitors, particularly in terms of their cost-effectiveness. A clear and ethical argument exists in support of attempts to both modify unrealistic patient expectations where they exist, and to enhance the knowledge base of prescribers. Greater concordance between physicians', patients' and caregivers' treatment goals, and appropriate prescription of these agents in line with available research will require more complete patient and caregiver information on the one hand, and potentially a shift in emphasis to more individualized, clinically focused outcomes, on the other.

The impact of perceived treatment assignment on smoking cessation outcomes among African-American smokers

BACKGROUND

The double-blind placebo-controlled design is commonly considered the gold standard in research methodology; however, subject expectation bias could subvert blinding.

OBJECTIVE

The primary aim of this study was to examine the impact of expectation bias. Specifically, we examined perceived treatment assignment on smoking cessation outcome rates among participants enrolled in a clinical trial of bupropion (150 mg SR, BID).

DESIGN

Analyses were conducted on data collected during "Kick It at Swope," a double-blind, placebo-controlled, randomized trial of 600 African-American smokers. Chi-square and multiple logistic regression analyses were used to examine the impact of perception of assignment on treatment effect and cotinine-verified smoking abstinence rates.

PARTICIPANTS

Participants were predominantly middle-aged (mean 44.7, SD 11.2), African-American women (68.6%), who smoked 19 CPD (SD = 8.1). Most had completed at least a high school education or GED (51.6%), and 55% had a monthly family income <$1,800.

MEASUREMENTS

At week 6 (end of treatment) and week 26 (end of study), participants were asked to report their perceived treatment group assignment. Self-reported abstinence (weeks 6 and 26) was confirmed using CO and cotinine biochemical verification.

RESULTS

After adjusting for actual treatment assignment, age and baseline cotinine, participants who perceived being assigned to bupropion vs. placebo were more likely to be abstinent at weeks 6 (OR = 2.07, 95% CI: 1.29 to 3.33, p = 0.002) and 26 (OR = 1.85, 95% CI: 1.05 to 3.24, p = 0.032).

CONCLUSIONS

Results support previous research that expectation bias associated with judgment of treatment assignment is a strong predictor of outcome and confirms this relationship in a smoking cessation trial using bupropion SR among African-American smokers.