Goal activation, expectations, and the placebo effect

Handling Ibuprofen increases pain tolerance and decreases perceived pain intensity in a cold pressor test

Pain contributes to health care costs, missed work and school, and lower quality of life. Extant research on psychological interventions for pain has focused primarily on developing skills that individuals can apply to manage their pain. Rather than examining internal factors that influence pain tolerance (e.g., pain management skills), the current work examines factors external to an individual that can increase pain tolerance. Specifically, the current study examined the nonconscious influence of exposure to meaningful objects on the perception of pain. Participants (N = 54) completed a cold pressor test, examined either ibuprofen or a control object, then completed another cold pressor test. In the second test, participants who previously examined ibuprofen reported experiencing less intense pain and tolerated immersion longer (relative to baseline) than those who examined the control object. Theoretical and applied implications of these findings are discussed.

Designing a placebo device: involving service users in clinical trial design

Background

Service users are increasingly involved in the design of clinical trials and in product and device development. Service user involvement in placebo development is crucial to a credible and acceptable placebo for clinical trials, but such involvement has not yet been reported.

Aims

To enhance the design of a future clinical trial of hand splints for thumb‐base osteoarthritis (OA), service users were involved in splint selection and design of a placebo splint. This article describes and reflects on this process.

Design

Two fora of service users were convened in 2011. Service users who had been prescribed a thumb splint for thumb‐base OA were approached about involvement by Occupational Therapy (OT) practitioners.

Content of the fora

A total of eight service users took part in the fora. Service users discussed their experience of OA and their own splints and then tried a variety of alternative splints. Through this they identified the active features of splints alongside acceptable and unacceptable design features. Service users focused on wearability and support with or without immobilization. Fora discussed whether a placebo group (‘arm’) was an acceptable feature of a future trial, and service users developed a potential design for a placebo splint.

Conclusion and discussion

This is the first project that to involve service users in placebo design. Service users are increasingly involved in product and device design and are ideally placed to identify features to make a placebo credible yet lacking key active ingredients. The future trial will include research into its acceptability.

Mobilizing unused resources: using the placebo concept to enhance cognitive performance

People have significant psychological resources to improve their well-being and performance, but these resources often go unused and could be better harnessed. In the medical domain, it is well established that these resources can be mobilized under certain conditions, for example in the context of the placebo effect. Here we explored whether the placebo principle can be used to enhance cognitive performance. To do so, we employed a modified placebo induction--a bogus priming method that we told participants would unconsciously enhance their knowledge and that they should hence trust their skills in an upcoming knowledge test. Participant performance was indeed enhanced, compared to a group that did not think the priming process would improve their knowledge. The study documents the relevance of the placebo effect outside the medical and therapeutic setting.

A direct test of the influence of nicotine response expectancies on the subjective and cognitive effects of smoking

Regardless of actual nicotine content, expectations about the nicotine content of a cigarette influence the rewarding subjective effects of smoking, and may even affect cognitive performance. These effects are theorized to be mediated by beliefs about effects of cigarette smoking, or response expectancies. However, few studies have directly manipulated response expectancies. Understanding the effects of such manipulations could improve effectiveness of nicotine-dependence treatments and medications. Using a 2 × 2 between-subjects factorial design, cigarette smokers (N = 80) smoked either a nicotine or a placebo (denicotinized) cigarette crossed with instructions that the cigarette would either enhance or impair cognitive and motor performance. As predicted, participants in the "told enhance" condition reported significantly greater beliefs that nicotine had beneficial effects on performance than those in the "told impair" condition. Compared to those "told impair," those "told enhance" reported more psychological reward, enjoyable physical sensations, and craving reduction from the cigarette, as well as greater motivation to perform well on a cognitive task. Relative to placebo cigarettes, nicotine cigarettes produced greater reports of satisfaction, craving reduction, and dizziness. Smoking a nicotine cigarette produced better performance on the Rapid Visual Information Processing Task, a test of sustained attention; but the expectancy manipulation had no effect. These data suggest that response expectancies can be experimentally manipulated and can influence perceived rewarding effects of cigarette smoking, but do not appear to affect cognitive performance. These findings add to our understanding of the benefits and limitations of expectancy manipulations, both experimentally and as a treatment technique.

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.

Placebo analgesia: cognitive influences on therapeutic outcome

The therapeutic response to a drug treatment is a mixture of direct pharmacological action and placebo effect. Therefore, harnessing the positive aspects of the placebo effect and reducing the negative ones could potentially benefit the patient. This article is aimed at providing an overview for clinicians of the importance of contextual psychosocial variables in determining treatment response, and the specific focus is on determinants of the placebo response. A better understanding of the physiological, psychological, and social mechanisms of placebo may aid in predicting which contexts have the greatest potential for inducing positive treatment responses. We examine the evidence for the role of psychological traits, including optimism, pessimism, and the effect of patient expectations on therapeutic outcome. We discuss the importance of the patient-practitioner relationship and how this can be used to enhance the placebo effect, and we consider the ethical challenges of using placebos in clinical practice.

Can the 8-Coil Shakti Alter Subjective Emotional Experience? A Randomized, Placebo-Controlled Study

At present, a commercially available device (the 8-coil Shakti) claims to produce weak and complex magnetic fields that alter neurobiological processes. The effects of the Shakti on emotional responses to photographs that varied on emotional valence were investigated. Participants ( N = 37) were exposed to either 30 min. of magnetic fields or a sham condition and rated their emotional reactions to a set of 54 color photographs. Although participants indicated significantly different emotional responses to images with distinct emotional valences, exposure to magnetic fields did not affect these responses, nor significantly interact with image emotional valence. Although the device's “amygdala signal” had no effect on the emotive response to images in this study, additional investigations examining the effects of weak and complex magnetic fields on various aspects of perception and cognition are warranted.

Motivation and placebos: do different mechanisms occur in different contexts?

This paper challenges the common assumption that the mechanisms underlying short-term placebo paradigms (where there is no motivation for health improvement) and long-term placebo paradigms (where patients value improvement in their health) are the same. Three types of motivational theory are reviewed: (i) classical placebo motivation theory that the placebo response results from the desire for therapeutic improvement; (ii) goal activation model that expectancy-driven placebo responses are enhanced when the placebo response satisfies an activated goal; and (iii) motivational concordance model that the placebo response is the consequence of concordance between the placebo ritual and significant intrinsic motives. It is suggested that current data are consistent with the following theory: response expectancy, conditioning and goal activation are responsible for short-term placebo effects but long-term therapeutic change is achieved through the effects of goal satisfaction and affect on the inflammatory response system and hypothalamic-pituitary-adrenal axis. Empirical predictions of this new theory are outlined, including ways in which placebo effects can be combined with other psychologically mediated effects on short-term and long-term psychological and physiological state.

Placebo expectations and the detection of somatic information

In a laboratory study we examined the hypothesis that placebo expectations enhance the initial identification of placebo-relevant sensations over placebo-irrelevant sensations. Participants (N = 102) were randomly assigned to one of three expectation groups. In the first group, participants ingested a placebo capsule and were told it was caffeine (deceptive expectation). In a second group, participants ingested a placebo capsule and were told it may be caffeine or it may be a placebo (double-blind expectation). Participants in the third group were given no expectation. All participants then tallied the placebo-relevant and placebo-irrelevant sensations they experienced during a 7-min period. Participants in the deceptive expectation group identified more placebo-relevant sensations than placebo-irrelevant sensations. No-expectation participants identified more placebo-irrelevant sensations than placebo-relevant sensations. Participants given the double-blind expectation identified an equal amount of placebo-relevant and irrelevant sensations. The amount of both placebo-relevant and placebo-irrelevant sensations detected mediated the relationship between the expectation manipulation and subsequent symptom reports. These data support the position that expectations cause placebo responding, in part, by altering how one identifies bodily sensations.

Dispositional optimism predicts placebo analgesia

Based on prior research identifying dispositional optimism as a predictor of placebo responding, the present study tested the hypothesis that individuals high in optimism would be more likely to respond to a placebo analgesic. Optimists and pessimists were randomly assigned to a placebo expectation condition or a no expectation condition before a cold pressor task. Blood pressure and heart rate were recorded before and during the cold pressor task, and participant ratings of pain and expectations were obtained immediately after the task. Analysis of the expectation manipulation revealed that the placebo instruction was successful in altering participant expectancy during the cold pressor. Supporting the main hypothesis, dispositional optimism was associated with lower pain ratings in the placebo condition but not in the control condition. Because dispositional optimism can alter placebo responding to laboratory pain, future studies should examine the potential role that this individual difference factor may play in patient responsivity to pharmacological and nonpharmacological treatments for clinical pain.

PERSPECTIVE

This study examined the possibility that individual differences can predict placebo analgesia. Participants were randomly assigned to receive either a placebo expectation or no expectation before a cold pressor task. Dispositional optimism was related to less cold pressor pain in the placebo condition as compared with the control condition.

Concept priming and pain: an experimental approach to understanding gender roles in sex-related pain differences

Prior research has found that sex differences in pain are partially due to individual variations in gender roles. In a laboratory study, we tested the hypothesis that the presence of covert gender role cues can also moderate the extent to which women and men experience pain. Specifically, we varied gender role cues by asking male and female participants to write about instances in which they behaved in a stereotypically feminine, masculine, or neutral manner. Pain and cardiovascular reactivity to the cold pressor task were then assessed. Results revealed that, when primed with femininity, men reported less pain and anxiety from the cold pressor task than women. However, no differences existed between the sexes in the masculine or neutral prime conditions. The results indicate that covert gender cues can alter pain reports. Further, at least in some situations, feminine role cues may be more influential on pain reports than masculine role cues.

A neuropsychological model of pain: research and clinical implications

This focus article argues that it may be useful to consider, and expand research into, studying the associations between psychological treatments and cortical activity. Matching our current understanding of the content and goals of psychological pain treatments with knowledge regarding the primary cortical areas involved in the processing and experience of pain provides an initial step towards a neuropsychological model of pain. This model can be used to: (1) inform research and increase knowledge about the associations between cortical activity, pain treatment, and pain experience; (2) facilitate communication about psychological treatments with patients to facilitate treatment engagement; and (3) help guide the development of more effective treatment plans. In this way, the development, testing, and modification of a neuropsychological model of pain could result in more patients receiving more effective care.

PERSPECTIVE

A model that describes the effects of psychological treatments on specific pain-related cortical areas and processes could inform researchers who test hypotheses concerning the mechanisms of those treatments, and help pain clinicians develop more effective treatment plans.

Effects of paroxetine on emotional functioning and treatment awareness: a 4-week randomized placebo-controlled study in healthy clinicians

OBJECTIVE

The objective of our study was to evaluate the effects of paroxetine on emotional functioning in three arms: double-blind paroxetine (DBPX), single-blind paroxetine (SBPX), and double-blind placebo (DBPO). Healthy psychologists and psychiatrists were elected for their ability to analyze with correct sensibility changes in their emotions.

METHOD

Thirty nonanxious, nondepressed participants working as psychiatrists (N = 18) or psychologists (N = 12) were randomly assigned to receive an ambulatory treatment with paroxetine (DBPX N = 10, SBPX N = 10) or placebo (DBPO N = 10). Paroxetine was administered for 4 weeks at 20 mg/day. Emotional functioning was evaluated with the Emotional State Questionnaire (ESQ), a self-questionnaire designed to assess four emotional dimensions: "recognition," "expression," "internal emotional experience," and "social context." Changes in emotional measures from baseline to D0, D7, D14, D28, and D42 were compared between treatment groups.

RESULTS

Analyses of ESQ showed in DBPX a significant decrease from baseline to D28 in internal emotional experience as compared to SBPX and DBPO groups. A different influence of gender between treatment groups on emotional recognition was observed.

CONCLUSIONS

This is the first study assessing the impact of a 4-week paroxetine treatment on emotional functioning in healthy psychiatrists and psychologists. The DBPX group was distinguishable from both SBPX and DBPO groups by a decrease in internal emotional experience, suggesting that two factors could be involved in the clinical response to paroxetine: a decrease in emotional feeling and treatment awareness.

A duty to deceive: placebos in clinical practice

Among medical researchers and clinicians the dominant view is that it is unethical to deceive patients by prescribing a placebo. This opinion is formalized in a recent policy issued by the American Medical Association (AMA [Chicago, IL]). Although placebos can be shown to be always safe, often effective, and sometimes necessary, doctors are now effectively prohibited from using them in clinical practice. I argue that the deceptive administration of placebos is not subject to the same moral objections that face other forms of deception in clinical practice and medical research. Although deception is normally objectionable on the grounds that it limits autonomy and breaches trust, these grounds do not apply to placebos when they are prescribed within appropriate ethical limits. Patients have reason to prefer that doctors can prescribe placebos in ethically responsible ways. Hence, the AMA has an obligation to endorse and to promote the responsible use of deceptive placebos in clinical practice.

Development of a patient-reported assessment to identify placebo responders in a generalized anxiety disorder trial

Placebo response is thought to be a primary contributor to uninformative (failed) trials in clinical drug development. This study describes the development of a patient-reported assessment to detect likely placebo responders. A novel scale, the Placebo Response Screening Scale (PRSS), was developed to assess domains expected to be associated with placebo response. The scale was administered during the screening visit of a 4-week, placebo-controlled study of alprazolam and an investigational compound in 211 patients with generalized anxiety disorder (GAD). Items that predicted placebo response were identified. Sensitivity and specificity of the instrument were used to determine a threshold score for use in screening likely placebo response. The PRSS was then evaluated by comparing active treatment and placebo groups and subsetting the groups based on subject PRSS scores. Twenty items were selected for being predictive of patient global improvement rating, clinician global improvement rating, or improvement on Hamilton Rating Scale for Anxiety (HAM-A) scores in placebo-arm patients. Receiver operating characteristic concordance values ranged from 0.77 to 0.96 for the different definitions of placebo responder. A cut-score of 50 on a scale of 0-100 was chosen to maximize sensitivity (range 0.67-0.79) and specificity (range 0.78-1.00). Fifty-six patients with scores of 50 or higher were flagged as potential placebo responders. Excluding these 56 patients from the analysis resulted in a greater separation of active treatment from placebo. The PRSS is a promising tool for predicting placebo response in clinical trials and requires further use and validation.

"Maybe I made up the whole thing": placebos and patients' experiences in a randomized controlled trial

Patients in the placebo arms of randomized controlled trials (RCT) often experience positive changes from baseline. While multiple theories concerning such "placebo effects" exist, peculiarly, none has been informed by actual interviews of patients undergoing placebo treatment. Here, we report on a qualitative study (n = 27) embedded within a RCT (n = 262) in patients with irritable bowel syndrome. Besides identical placebo acupuncture treatment in the RCT, the qualitative study patients also received an additional set of interviews at the beginning, midpoint, and end of the trial. Interviews of the 12 qualitative subjects who underwent and completed placebo treatment were transcribed. We found that patients (1) were persistently concerned with whether they were receiving placebo or genuine treatment; (2) almost never endorsed "expectation" of improvement but spoke of "hope" instead and frequently reported despair; (3) almost all reported improvement ranging from dramatic psychosocial changes to unambiguous, progressive symptom improvement to tentative impressions of benefit; and (4) often worried whether their improvement was due to normal fluctuations or placebo effects. The placebo treatment was a problematic perturbation that provided an opportunity to reconstruct the experiences of the fluctuations of their illness and how it disrupted their everyday life. Immersion in this RCT was a co-mingling of enactment, embodiment and interpretation involving ritual performance and evocative symbols, shifts in bodily sensations, symptoms, mood, daily life behaviors, and social interactions, all accompanied by self-scrutiny and re-appraisal. The placebo effect involved a spectrum of factors and any single theory of placebo--e.g. expectancy, hope, conditioning, anxiety reduction, report bias, symbolic work, narrative and embodiment--provides an inadequate model to explain its salubrious benefits.

When the expectations from a message will not be realized: Naïve theories can eliminate expectation-congruent judgments via correction

Research typically reveals that individuals like an object more when a persuasive message convinces them that this object is pleasant. In this paper, two experiments were conducted to understand the influence of such message-induced affective-expectations on judgments of experienced affect following direct encounter with an alcohol type of drink. As predicted, before trying the drink, recipients of the positive-expectation message had more positive expectations than recipients of the negative-expectation message. After drinking, participants judged the beverage to elicit affect congruent with message-induced expectations to the extent they did not endorse a naïve theory that their affective expectations congruently influence their experienced affect. In contrast, after drinking, the effect of the message disappeared when participants did endorse this naïve theory. Moderation of these effects, as well as theoretical and practical implications, are addressed.

Motivational concordance: an important mechanism in self-help therapeutic rituals involving inert (placebo) substances

We tested the contribution of two mechanisms, response expectancy and motivational concordance, to reported psychological benefit from a popular, biologically inactive, self-help, complementary therapy (a placebo). Flower essences were taken by 251 people for self-selected symptoms and were randomized to receive three different kinds of information. When the flower essence was presented as a spiritual therapy, then baseline spirituality (beta=.35, P=.01) and expectancy (beta=.25, P=.03) independently predicted outcome. When flower essences were presented as an affirmation (i.e., nonspiritual) therapy, then spirituality negatively (beta=-.27, P=.03) and expectancy (beta=.33, P=.01) predicted outcome. For both groups, expectancy predicted outcome after controlling for spirituality and compliance, but did not after controlling for ease of task completion. Expectancy failed to predict outcome in the nonenhanced ritual group. The results suggest that motivational concordance is an important therapeutic mechanism for real-life placebos.

[Clinical significance of the placebo effect]

Placebo controlled studies examining clinical problems, e.g. in pain therapy, are considered the "gold standard" for evidence-based medicine. In these studies the placebo effect itself is not the main focus of interest, but serves more as a control for the specificity of the effect of a certain treatment. What physicians in this context often do not realize is that the placebo effect itself represents a true measurable correlate of an organism's psycho-neurobiological response and, thereby, influences the healing process, e.g. the pain relief. Placebo is, therefore, not equivalent to "no treatment". The number of placebo responders, the degree and the duration of the placebo effect is not fixed, but are subject to a much greater variability then hitherto believed. The myth that placebo responders have a certain personality has not been proven correct; instead, the relationships between physicians and patients as well as sociocultural factors have a considerable impact on the placebo effect. Psychological theories explain that classical conditioning, enhanced expectation and motivation of the patient determine the degree of the placebo effect. These directly influence neurobiological systems such as the endogenous opioids which according to modern brain imaging are predominantly activated in pain-relevant areas and contribute to the effect of placebo analgesia. Placebo effects that should be deliberately excluded in controlled clinical trials, can be desirable in clinical practice to optimize the total therapeutic effect. This should mean that the context effect of each therapeutic intervention is maximized towards an improved therapeutic effect, as outlined in the recent AWMF guidelines for postoperative pain therapy, but should not include the administration of an inert substance. The latter is controlled by rigorous ethical guidelines and is only permitted in the context of ethically approved controlled clinical trials. A possible alternative is suggested by Benedetti et al. in which the hidden administration of an active substance identifies the specific response in contrast to the open application of the same substance characterizing the specific plus the placebo effect, after which the pure placebo effect can be determined.

Consistency of the placebo effect

OBJECTIVE

The existence of reliable personality predictors of the placebo effect is controversial. For prediction to be possible, the response to placebo must be reliable. We tested the consistency of the placebo effect by assessing the response to four trials of placebo analgesic treatment.

METHODS

Two identical experimental pain stimuli were administered simultaneously to matching fingers on both hands. Pain sensation was compared between one finger, which was treated with a placebo cream and the other which was not treated. Two placebo creams were used, each with a different label. The procedure was repeated between 1 and 8 days later using the same creams and order of presentation. Two personality traits (acquiescence and absorption) and response expectancy were assessed as potential predictors of the placebo effect.

RESULTS

Placebo effects across trials were highly correlated (r=.60 and .77) when placebos bore the same name but were not significantly correlated when placebos had different names. Placebo effects were significantly associated with response expectancy but not with acquiescence or absorption.

CONCLUSIONS

Context-specific predictions of placebo response (e.g., expectancy) are possible, but personality predictors will not be consistent across contexts.

A comprehensive review of the placebo effect: recent advances and current thought

Our understanding and conceptualization of the placebo effect has shifted in emphasis from a focus on the inert content of a physical placebo agent to the overall simulation of a therapeutic intervention. Research has identified many types of placebo responses driven by different mechanisms depending on the particular context wherein the placebo is given. Some placebo responses, such as analgesia, are initiated and maintained by expectations of symptom change and changes in motivation/emotions. Placebo factors have neurobiological underpinnings and actual effects on the brain and body. They are not just response biases. Other placebo responses result from less conscious processes, such as classical conditioning in the case of immune, hormonal, and respiratory functions. The demonstration of the involvement of placebo mechanisms in clinical trials and routine clinical practice has highlighted interesting considerations for clinical trial design and opened up opportunities for ethical enhancement of these mechanisms in clinical practice.

Evaluating readiness and treatment seeking effects in a pharmacotherapy trial for alcohol dependence

BACKGROUND

Decreases in drinking behavior prior to treatment onset often occur in pharmacotherapy trials for alcohol dependence. We propose that these decreases are associated with both trait and state factors operating before initiation of treatment to influence participants' expectation or perception of future treatment outcome. While trait factors typically include personality traits, state factors can include readiness to change and severity of drinking at screening. Understanding the characteristics of changes in drinking early in the process of entering treatment can improve clinical trials and outcomes. Our goal was to evaluate drinking behavior before initiating a randomized, double-blind pharmacotherapy clinical trial for alcohol dependence.

METHODS

We examined the impact of personality factors associated with gregariousness or conformity on the MacAndrew Alcoholism Scale, as well as state factors measured by the Stages-of-Change Scale (based on the University of Rhode Island Change Assessment Scale) and quantity of drinking at screening, on pre-double-blind clinical outcome (i.e., drinking reduction) among 321 male and female alcoholics enrolled in a pharmacotherapy trial.

RESULTS

A significant reduction in alcohol consumption occurred among heavy drinkers between the baseline assessment (10.3 +/- 5.9 drinks per day) and the last week of single-blind placebo administration (5.3 +/- 5.1 drinks per day; p < 0.001). In contrast, the reduction in alcohol consumption by nonheavy drinkers over the same period was not significant (from 3.07 +/- 0.65 to 2.98 +/- 2.6 drinks per day; p > 0.05). Partial correlations indicated that the significant predictors of drinking reductions during this period were: level of drinking (-0.215) and the Stages-of-Change subscales of precontemplation (-0.152), contemplation (0.144), and maintenance (-0.284). Personality factors on the MacAndrew Alcoholism Scale did not predict drinking reductions during this same period.

CONCLUSIONS

Participants with higher motivation levels and greater drinking severity were most likely to reduce their drinking behavior before double-blind treatment. These state factors are important to consider when randomizing participants in trials, and are more important than trait or personality factors in accounting for the initial reduction in drinking in this population during the pretreatment period.

Further evidence for individual differences in placebo responding: an interactionist perspective

OBJECTIVE

A prior investigation found that individuals low in optimism are more likely to follow a negative placebo (nocebo) expectation. The present study tested the hypothesis that individuals high in optimism are more likely to follow a positive placebo expectation.

METHODS

Individuals (N=56) varying in their level of optimism were randomly assigned to one of three conditions. In the first condition, participants were given the expectation that a placebo sleep treatment would improve their sleep quality (placebo expectation condition). In the second condition, participants engaged in the same sleep treatment activity but were not given the positive placebo expectation (treatment control condition). Finally, a third group did not receive the positive placebo expectation and also did not engage in the placebo sleep treatment (no-placebo control condition).

RESULTS

Optimism was positively associated with better sleep quality in the placebo expectation condition (r=.48, P<.05). Optimism scores were not associated with better sleep quality in either the treatment control condition (r=-.17, P=.46) or the no-placebo control condition (r=-.24, P=.35).

CONCLUSION

Dispositional optimism relates to placebo responding. This relationship, however, is not manifested in a simple increase or decrease in all types of placebo responding. Rather, it appears that, as optimism increases, response to the positive placebo expectation increases, whereas response to nocebo expectation decreases. It is recommended that future research on personality and placebo effects consider the interaction between situational and dispositional variables.

Dispositional predictors of placebo responding: a motivational interpretation of flower essence and gratitude therapy

OBJECTIVES

The aim of this study was to test a motivational interpretation of placebo responding using two different types of placebo therapy, one using flower essences and the other a nonspecific psychological therapy. The motivational concordance interpretation is that therapeutic rituals that are consistent with self-defining or self-actualizing goals have a nonspecific therapeutic benefit independently of expectancy.

METHODS

Study 1 was a replication of an earlier flower essence outcome study but with additional outcome and predictor variables: 167 people completed questionnaires in return for free flower essence treatment. Predictor variables consisted of two measures of spirituality, optimism, expectancy, and attitudes and beliefs to complementary medicine. Outcome was assessed after 3 weeks. In Study 2, 90 people took part in "gratitude therapy" for improved sleep quality over one night in return for questionnaire completion (trait gratitude, spirituality, and expectancy).

RESULTS

Study 1 confirmed previous research: Trait spirituality predicted perceived improvement. This improvement was independent of optimism (P<.001), cannot be explained by acquiescence or social desirability, and was independent of a highly conservative test of expectancy (P=.02). In Study 2, trait gratitude predicted perceived sleep improvement independently of expectancy (P=.01): Spirituality did not correlate with improvement.

CONCLUSIONS

These data suggest that in addition to expectations, degree of engagement in a positive, therapeutic ritual determines the extent of the placebo response. The placebo response depends in part on the interaction (i.e., the degree of concordance) between the type of therapy and the participant's personality: Dispositional predictors vary with the type of placebo therapy.

Interactive effects of alcohol outcome expectancies and alcohol cues on nonconsumptive behavior

Experimental research and popular belief suggest that, among its many effects, alcohol consumption reduces tension and facilitates aggression. Such observations could result from direct, pharmacological effects of alcohol on neural control of behavior but also may be accounted for by positing that drinking behavior activates mental representations of relaxation-related or aggression-related alcohol expectancies in long-term memory. Building on this latter view, in 2 experiments, the authors investigated whether rudimentary drinking-related cues, which presumably activate encoded alcohol expectancies, facilitate tension reduction and hostility in the complete absence of actual or placebo alcohol consumption. In Experiment 1, following contextual exposure to alcohol-related words, individuals with stronger expectancies that drinking reduces tension showed an increased willingness to meet with an opposite-gender stranger under relatively anxiety-provoking circumstances, suggesting that they experienced less apprehension regarding the meeting. Analogously, in Experiment 2, following near-subliminal exposure to alcohol-related words, individuals with stronger expectancies that drinking fosters aggression showed greater hostility toward a target person following an experimentally engineered provocation. Neither of the latter effects was obtained following exposure to nonalcoholic beverage words, which presumably did not activate alcohol outcome expectancy representations in long-term memory. Moreover, the strength of relevant, content-specific expectancies (i.e., for tension reduction or aggression, respectively) moderated alcohol cue exposure effects, but the strength of other expectancies (e.g., for sociability or sexual arousal) did not. Together, these findings demonstrate that exposure to rudimentary alcohol cues independently engenders expectancy-consistent behavior, thereby attesting to the remarkable breadth and subtlety of the behavioral impact of alcohol expectancy activation.

Expectations and associations that heal: Immunomodulatory placebo effects and its neurobiology

The use of placebo may have accompanied healing and medical practices since their origins (Plato; Charmides, 155-156). Recent experimental data indicate that we would be well advised to further consider placebo effects in future therapeutic strategies, with a better knowledge of their potency, psychological basis and underlying neurobiological mechanisms. Current research in the areas of pain, depression and Parkinson's disease has uncovered some of the potential neurobiological mechanisms of placebo effects. These data indicate that conscious expectation and unconscious behavioral conditioning processes appear to be the major neurobiological mechanisms capable of releasing endogenous neurotransmitters and/or neurohormones that mimic the expected or conditioned pharmacological effects. To date, research on placebo responses affecting immune-related diseases is scarce, but there are consistent indications that skin and mucosal inflammatory diseases, in particular, are strongly modulated by placebo treatments. However, the brain's capability to modulate peripheral immune reactivity has been impressively demonstrated by paradigms of behavioral conditioning in animal experiments and human studies. Thus, placebo effects can benefit end organ functioning and the overall health of the individual through positive expectations and behavioral conditioning processes.

Expectations and Placebo Response: A Laboratory Investigation into the Role of Somatic Focus

It has been theorized that expectations are an important causal determinant of the placebo effect. Placebo expectations, however, do not always yield placebo effects. In a laboratory study, we tested the hypothesis that one's level of somatic focus moderates the effect of placebo expectations on placebo responding. We also varied whether participants were told the placebo was a drug, could either be a drug or placebo, or was a placebo. The results revealed that individuals who thought they were taking a drug (i.e., unconditional expectations) reported more placebo symptoms when they closely focused on their symptoms. Individuals told they may or may not be receiving a drug (i.e., conditional expectations) did not differ from control participants regardless of how closely they attended to their symptoms. The findings have theoretical implications for expectancy models of the placebo effect as well as for practical research comparing the type of expectations held by individuals in clinical trials and clinical practice.