Mechanisms and clinical implications of the placebo effect: is there a potential for the elderly? A mini-review

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

PURPOSE

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

CONCLUSION

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

The development of the Therapeutic Group Context Questionnaire: Reliability and validity measures based on telehealth Group-based Pain Management Programs

INTRODUCTION

In 2016, the Centers for Disease Control and Prevention analyzed the National Health Interview Survey data and found that the occurrence of chronic pain and high-impact chronic pain in the USA was 20.4% and 8%, respectively. Group-based Pain Management Programs have been viewed as significant treatments aiding patients with self-management of chronic pain. The onset of coronavirus disease 2019 (COVID-19) at the beginning of 2020, widely eliminated the in-person Group-based Pain Management Programs. The exploration of therapeutic contextual factors such as the therapeutic alliance and group dynamics in telehealth Group-based Pain Management Programs appears warranted for which reason the Therapeutic Group Context Questionnaire was developed.

METHODS

The therapeutic alliance and group dynamics items in the Therapeutic Group Context Questionnaire were developed from an extensive literature review and underwent examination of content validity, internal consistency, reliability, and validity through telehealth Group-based Pain Management Programs.

RESULTS

Content validity of the Therapeutic Group Context Questionnaire was established in five separate stages and the psychometrics of the Therapeutic Group Context Questionnaire was found to be very good with high internal consistency and reliability (r = 0.85-0.97) and the ability of the Therapeutic Group Context Questionnaire to differentiate between high and low scorers on the SF-36 emotional well-being measure.

DISCUSSION

The examination of therapeutic contextual factors via telehealth Group-based Pain Management Programs using the Therapeutic Group Context Questionnaire appears possible in view of the very good psychometric properties described above. Investigation of therapeutic contextual factors through the Therapeutic Group Context Questionnaire may provide greater insight into the role that these factors may have in telehealth programs and their impact on pain outcomes. Future investigation of the Therapeutic Group Context Questionnaire in non-telehealth Group-based Pain Management Programs, as well as, other disorders being addressed via telehealth appears warranted.

Differences between experimental and placebo arms in manual therapy trials: a methodological review

BACKGROUND

To measure the specific effectiveness of a given treatment in a randomised controlled trial, the intervention and control groups have to be similar in all factors not distinctive to the experimental treatment. The similarity of these non-specific factors can be defined as an equality assumption. The purpose of this review was to evaluate the equality assumptions in manual therapy trials.

METHODS

Relevant studies were identified through the following databases: EMBASE, MEDLINE, SCOPUS, WEB OF SCIENCE, Scholar Google, clinicaltrial.gov, the Cochrane Library, chiloras/MANTIS, PubMed Europe, Allied and Complementary Medicine (AMED), Physiotherapy Evidence Database (PEDro) and Sciencedirect. Studies investigating the effect of any manual intervention compared to at least one type of manual control were included. Data extraction and qualitative assessment were carried out independently by four reviewers, and the summary of results was reported following the PRISMA statement.

RESULT

Out of 108,903 retrieved studies, 311, enrolling a total of 17,308 patients, were included and divided into eight manual therapy trials categories. Equality assumption elements were grouped in three macro areas: patient-related, context-related and practitioner-related items. Results showed good quality in the reporting of context-related equality assumption items, potentially because largely included in pre-existent guidelines. There was a general lack of attention to the patient- and practitioner-related equality assumption items.

CONCLUSION

Our results showed that the similarity between experimental and sham interventions is limited, affecting, therefore, the strength of the evidence. Based on the results, methodological aspects for planning future trials were discussed and recommendations to control for equality assumption were provided.

Attitudes Toward a Pre-authorized Concealed Opioid Taper: A Qualitative Analysis of Patient and Clinician Perspectives

Standard opioid tapers tend to be associated with increased patient anxiety and higher pain ratings. Pre-authorized concealed opioid reductions may minimize expectations such as fear of increased pain due to the reduction of opioids and, prolong analgesic benefits in experimental settings. We recently observed that patients and clinicians are open to concealed opioid tapering. However, little is known about the "why" behind their attitudes. Based on this lack of data, we analyzed qualitative responses to survey questions on patients' and clinicians' acceptance of a concealed opioid reduction for chronic pain. Seventy-four patients with a history of high dose opioid therapy and 49 clinicians completed a web-based questionnaire with open-ended questions examining responses to two hypothetical clinical trials comparing a concealed opioid reduction pre-authorized by patients vs. standard tapering. We used content analysis based on qualitative descriptive methodology to analyze comments from the patients and clinicians. Five themes were identified: informed consent; anxiety; safety; support; and ignorance is bliss, or not. These themes highlight the overall positive attitudes toward concealed opioid tapers. Our findings reinforce the importance of patient-centered care and are expected to inform the design of clinical trials from both the patient and clinician perspective. This qualitative study presents patients' and clinicians' attitudes toward hypothetical scenarios for a trial of pre-authorized reduction of opioids. The findings indicate positive attitudes and the relevance of engaging patients with effective decision-making processes.

A Meta-Analysis of Therapeutic Pain Neuroscience Education, Using Dosage and Treatment Format as Moderator Variables

OBJECTIVES

This meta-analysis aimed to assess the overall effect of therapeutic pain neuroscience education (TPNE) on chronic musculoskeletal pain and to further assess whether such an effect differs by TPNE dosage as well as other treatment format components. Dosage included the number of TPNE sessions provided as well as the amount of time per TPNE session. Structural components included TPNE provided alone as treatment or combined with other pain management modalities, as well as the inclusion of group-based treatment sessions.

METHODS

Electronic databases were utilized to search for randomized controlled trials that included TPNE. The overall effectiveness of TPNE was estimated on 4 pain outcome measures, including kinesiophobia, pain intensity, pain disability, and pain catastrophizing. The differential effectiveness of TPNE was examined using a mixed-methods moderator analysis on various study-level characteristics to identify potential moderators affecting the overall results.

RESULTS

Significant effects of TPNE were found on all the outcome measures. The only moderator that displayed a significant effect was group-based treatment on kinesiophobia (z = -2.23, P < 0.05, 95% confidence interval [CI] -2.70 to -0.20). Between-group analysis revealed that only interventions that included group sessions were found to be statistically significant (z = 2.20, P < 0.05) and displayed a large effect size (d = 0.80, 95% CI 0.09 to 1.50).

DISCUSSION

Therapeutic pain neuroscience education had a statistically significant impact on all the explored pain outcome measures. However, when investigating the treatment dosage and format moderator variables, they appeared to not have a statistically significant effect except for group-based interventions on kinesiophobia levels.

CONCLUSION

This meta-analysis examined the efficacy of TPNE for patients with chronic pain. It assessed various pain outcome measures following intervention. In addition, this research identified that various moderator variables do not have and do have an impact on the treatment modality of TPNE.

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

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

[The learned placebo response in the immune system]

The learned placebo response of the immune system is based on the mutual interaction between the brain and the immune system; both systems continually exchange information via humoral and neural communication pathways. This communication network enables the modification, i.e. suppression or stimulation, of peripheral immune functions by classical or Pavlov's conditioning. The present article provides an overview of the results of recent experimental animal studies, which also document the potential clinical relevance of learned immune responses. Learned immunological responses mediated by classical conditioning have also been demonstrated in humans. The knowledge gained from experimental data and clinical observations paves the way for a potential implementation of learned immune responses as supportive measures to standard immunopharmacological treatment strategies to reduce drug dosage as well as adverse side effects while simultaneously maximizing the therapeutic effect.

Reinterpreting homoeopathy in the light of placebo effects to manage patients who seek homoeopathic care: A systematic review

Homoeopathy is widespread, and users claim to benefit from it. However, clear evidence of its efficacy over placebo is not available to date. As a consequence, a social separation between homoeopathy users and mainstream medicine exists, exposing these patients to many risks. Our primary objective is to assess homoeopathy efficacy by systematically reviewing existing systematic reviews and meta-analyses and to systematically review trials on open-label placebo (OLP) treatments. A secondary objective is to understand if homoeopathy as a whole may be considered as a placebo treatment. PubMed/Medline, Embase, Google Scholar, and Cochrane Library were systematically searched for systematic reviews and meta-analyses on homoeopathy efficacy, and 61 studies were included. Same databases plus Journal of Interdisciplinary Placebo Studies (JIPS) were also systematically searched for randomised controlled trials (RCTs) on OLP treatments, and 10 studies were included. Databases were searched up to 24 February 2018. Two authors independently screened all retrieved articles and selected studies eligible for inclusion. The quality of reviews of included studies was evaluated with a dedicated NIH tool in the first review, whereas the risk of bias of trials of included studies was assessed with the specific Cochrane tool in the second review. Qualitative syntheses show that homoeopathy efficacy can be considered comparable to placebo, and that OLP treatments may be effective in some health conditions. Placebo effects like placebo itself, treatment context, physician-patient relationship, and other nonspecific factors can define the idea of placebo treatments, which may be effective in some conditions. If homoeopathy efficacy is comparable to placebo, and if placebo treatments can be effective in some conditions, then homoeopathy as a whole may be considered as a placebo treatment. Reinterpreting homoeopathy as a placebo treatment would define limits and possibilities of this practice. This perspective shift suggests a strategy to manage patients who seek homoeopathic care and to reconcile them with mainstream medicine in a sustainable way.

Clinical Use of Placebo Effects in Patients With Pain Disorders

The analgesic placebo effect is well documented by numerous studies. Many important influencing factors, however, are yet to be discovered. In the arena of placebo effects and clinical implications, expectancies play a central role. Expectancies are shaped by processes of classical and social learning as well as verbal instructions and are strongly related to emotional factors. Expectancies trigger a cascade of endogenous opioids and non-opioids, which alter the experience of pain. For clinical application it is important to know, that placebo research yields ethical possibilities to use placebo effects without deception and without using placebos. Since placebo effects contribute to responses to active analgesics, it is feasible to enhance patients' benefits from pain treatments by increasing the additional placebo effect. There are several possibilities to use the placebo effects via shaping and adapting information about analgesic medication and via associating medication intake with a positive context. A positive patient-clinician communication atmosphere is very important to generate clinically meaningful placebo effects in pain medicine.

A noninterventional study evaluating the effectiveness of rotigotine and levodopa combination therapy in younger versus older patients with Parkinson's disease

BACKGROUND

PD0013 was a 6-month noninterventional study in clinical practice comparing effectiveness/tolerability of rotigotine+levodopa in younger (<70 years) vs. older (≥70 years) Parkinson's disease (PD) patients.

METHODS

Patients previously received levodopa for ≥6 months as monotherapy/in combination with another dopamine-agonist (DA). Primary variable: Unified PD Rating Scale (UPDRS) Part-II change from baseline to end-of-observation-period (EOP).

RESULTS

91 younger/99 older patients started rotigotine; 68 younger/62 older patients completed the study. Most switched from levodopa+another DA. Addition of rotigotine as first DA was more common in older patients (20.2% vs.15.4%). Mean ± SD rotigotine-exposure: 6.1 ± 3.4 mg/24h younger vs. 4.9 ± 2.4 mg/24h older. Eleven patients changed levodopa dose. At EOP, improvement in mean UPDRS-II was greater in younger patients (p = 0.0289). UPDRS-II responder-rate (≥20% decrease in UPDRS-II score) was higher in younger patients (42.3% vs. 25.9%). Improvement across age groups was similar on PD Sleep Scale-2 and Clinical Global Impressions-Improvement Scale. Adverse drug reactions (ADRs), and discontinuations because of ADRs, were more common among older patients. There were no new safety signals.

CONCLUSIONS

Despite low rotigotine doses, when added to levodopa/switched from levodopa+another DA, rotigotine led to greater improvement in UPDRS-II in younger patients (<70 years). Individual patient data revealed clinically meaningful improvements in UPDRS-II in both groups.

Role of the Prefrontal Cortex in Pain Processing

The prefrontal cortex (PFC) is not only important in executive functions, but also pain processing. The latter is dependent on its connections to other areas of the cerebral neocortex, hippocampus, periaqueductal gray (PAG), thalamus, amygdala, and basal nuclei. Changes in neurotransmitters, gene expression, glial cells, and neuroinflammation occur in the PFC during acute and chronic pain, that result in alterations to its structure, activity, and connectivity. The medial PFC (mPFC) could serve dual, opposing roles in pain: (1) it mediates antinociceptive effects, due to its connections with other cortical areas, and as the main source of cortical afferents to the PAG for modulation of pain. This is a ‘loop’ where, on one side, a sensory stimulus is transformed into a perceptual signal through high brain processing activity, and perceptual activity is then utilized to control the flow of afferent sensory stimuli at their entrance (dorsal horn) to the CNS. (2) It could induce pain chronification via its corticostriatal projection, possibly depending on the level of dopamine receptor activation (or lack of) in the ventral tegmental area-nucleus accumbens reward pathway. The PFC is involved in biopsychosocial pain management. This includes repetitive transcranial magnetic stimulation, transcranial direct current stimulation, antidepressants, acupuncture, cognitive behavioral therapy, mindfulness, music, exercise, partner support, empathy, meditation, and prayer. Studies demonstrate the role of the PFC during placebo analgesia, and in establishing links between pain and depression, anxiety, and loss of cognition. In particular, losses in PFC grey matter are often reversible after successful treatment of chronic pain.

Transcutaneous electrical nerve stimulation and placebo analgesia: is the effect the same for young and older individuals?

Purpose

Placebo analgesia refers to a perceived reduction in pain intensity following the administration of a simulated or otherwise medically ineffective treatment. Previous studies have shown that many factors can influence the magnitude of placebo analgesia. However, few investigations have examined the effect of age on placebo analgesia, and none have done it in the context of electrotherapeutic interventions. The objective of this study is to compare the placebo response induced by sham transcutaneous electrical nerve stimulation (TENS) between young and older individuals, using an experimental heat-pain paradigm.

Patients and methods

Twenty-two young (21–39 years) and 22 older (58–76 years) healthy adults participated in this comparative study. Experimental heat pain was evoked with a thermode (2-min stimulation at a constant individually adjusted temperature) applied on the lumbar region. Participants were asked to evaluate the intensity of their pain using a computerized visual analog scale. Experimental pain was induced before and after an unconditioned placebo intervention (placebo TENS) applied for 25 min.

Results

In young individuals, no significant pain reductions were noted, whereas in older individuals, a statistically significant pain reduction was observed after the placebo stimulation (P<0.01). Between-group analyses revealed that placebo analgesia was greater in older individuals (40% pain reduction) compared with young individuals (15% pain reduction) (P<0.05). However, sham TENS increased heat-pain thresholds in the young group (P<0.01), but not in the older group (P=0.43).

Conclusion

Our results indicate that placebo analgesia is influenced by age, with older individuals showing larger placebo analgesia than young adults. Although these results should be confirmed in clinical pain populations, the current observations bear potentially important consequences for the design of future placebo-controlled trials and for healthcare professionals working with elderly patients.

Clinical relevance of contextual factors as triggers of placebo and nocebo effects in musculoskeletal pain

Placebo and nocebo effects are embodied psycho-neurobiological responses capable of modulating pain and producing changes at different neurobiological, body at perceptual and cognitive levels. These modifications are triggered by different contextual factors (CFs) presented in the therapeutic encounter between patient and healthcare providers, such as healing rituals and signs. The CFs directly impact on the quality of the therapeutic outcome: a positive context, that is a context characterized by the presence of positive CFs, can reduce pain by producing placebo effects, while a negative context, characterized by the presence of negative CFs, can aggravate pain by creating nocebo effects. Despite the increasing interest about this topic; the detailed study of CFs as triggers of placebo and nocebo effects is still lacked in the management of musculoskeletal pain.

Increasing evidence suggest a relevant role of CFs in musculoskeletal pain management. CFs are a complex sets of internal, external or relational elements encompassing: patient’s expectation, history, baseline characteristics; clinician’s behavior, belief, verbal suggestions and therapeutic touch; positive therapeutic encounter, patient-centered approach and social learning; overt therapy, posology of intervention, modality of treatment administration; marketing features of treatment and health care setting. Different explanatory models such as classical conditioning and expectancy can explain how CFs trigger placebo and nocebo effects. CFs act through specific neural networks and neurotransmitters that were described as mediators of placebo and nocebo effects.

Available findings suggest a relevant clinical role and impact of CFs. They should be integrated in the clinical reasoning to increase the number of treatment solutions, boosts their efficacy and improve the quality of the decision-making. From a clinical perspective, the mindful manipulation of CFs represents a useful opportunity to enrich a well-established therapy in therapeutic setting within the ethical border. From a translational perspective, there is a strong need of research studies on CFs close to routine and real-world clinical practice in order to underline the uncertainty of therapy action and help clinicians to implement knowledge in daily practice.

Preserved Capacity for Placebo Analgesia in the Elderly

The prevalence of chronic pain rises with increasing age. It has been suggested that the mechanisms responsible for the development of chronic pain overlap with mechanisms involved in aging, potentially implicating age-related changes in descending modulatory pathways. This observation raises the question whether other forms of endogenous pain modulation, in particular placebo analgesia, become compromised with age. Because of the known contribution of placebo effects to analgesic treatment outcomes this question is of important clinical relevance. In this study, we compared the response to thermal painful stimuli and the capacity for endogenous pain modulation between younger and older adults using a well established placebo analgesia paradigm involving expectancy and conditioning components. We recruited 30 younger (age 23-40 years, mean = 27.04, standard error of the mean ± .61) and 24 older adults (60-80 years, mean = 69.3, standard error of the mean ± .89). We observed increased heat pain thresholds and higher pain intensity ratings (in response to physically identical heat stimulation) in the older compared with the younger group. However, the placebo analgesic response was comparable between both age groups of healthy participants. The preserved capacity for placebo analgesia in our sample of older participants highlights the potential to use nonpharmacological analgesic treatment strategies in this age group and to exploit placebo mechanisms as an add-on to existing analgesic (pharmacological) treatment strategies.

PERSPECTIVE

In contrast to the commonly shared view that endogenous pain modulation declines with age we found a comparable capacity for placebo analgesia in a group of healthy older and younger adults.

Placebo Response is Driven by UCS Revaluation: Evidence, Neurophysiological Consequences and a Quantitative Model

Despite growing scientific interest in the placebo effect and increasing understanding of neurobiological mechanisms, theoretical modeling of the placebo response remains poorly developed. The most extensively accepted theories are expectation and conditioning, involving both conscious and unconscious information processing. However, it is not completely understood how these mechanisms can shape the placebo response. We focus here on neural processes which can account for key properties of the response to substance intake. It is shown that placebo response can be conceptualized as a reaction of a distributed neural system within the central nervous system. Such a reaction represents an integrated component of the response to open substance administration (or to substance intake) and is updated through “unconditioned stimulus (UCS) revaluation learning”. The analysis leads to a theorem, which proves the existence of two distinct quantities coded within the brain, these are the expected or prediction outcome and the reactive response. We show that the reactive response is updated automatically by implicit revaluation learning, while the expected outcome can also be modulated through conscious information processing. Conceptualizing the response to substance intake in terms of UCS revaluation learning leads to the theoretical formulation of a potential neuropharmacological treatment for increasing unlimitedly the effectiveness of a given drug.

Age and sex as moderators of the placebo response – an evaluation of systematic reviews and meta-analyses across medicine

Predictors of the placebo response (PR) in randomized controlled trials (RCT) have been searched for ever since RCT have become the standard for testing novel therapies and age and gender are routinely documented data in all trials irrespective of the drug tested, its indication, and the primary and secondary end points chosen. To evaluate whether age and gender have been found to be reliable predictors of the PR across medical subspecialties, we extracted 75 systematic reviews, meta-analyses, and meta-regressions performed in major medical areas (neurology, psychiatry, internal medicine) known for high PR rates. The literature database used contains approximately 2,500 papers on various aspects of the genuine PR. These ‘meta-analyses’ were screened for statistical predictors of the PR across multiple RCT, including age and gender, but also other patient-based and design-based predictors of higher PR rates. Retrieved papers were sorted for areas and disease categories. Only 15 of the 75 analyses noted an effect of younger age to be associated with higher PR, and this was predominantly in psychiatric conditions but not in depression, and internal medicine but not in gastroenterology. Female gender was associated with higher PR in only 3 analyses. Among the patient-based predictors, the most frequently noted factor was lower symptom severity at baseline, and among the design- based factors, it was a randomization ratio that selected more patients to drugs than to placebo, more frequent study visits, and more recent trials that were associated with higher PR rates. While younger age may contribute to the PR in some conditions, sex does not. There is currently no evidence that the PR is different in the elderly. PR are, however, markedly influenced by the symptom severity at baseline, and by the likelihood of receiving active treatment in placebo- controlled trials.

Moderation of antidepressant and placebo outcomes by baseline severity in late-life depression: A systematic review and meta-analysis

BACKGROUND

Baseline severity is a crucial moderator of trial outcomes in adult depression, with the advantage of antidepressants over placebo increasing as severity increases. However, this relationship has not been examined in late-life depression.

METHODS

PubMed, Embase, Web of Science, PsycINFO, and Cochrane were searched for studies published through September 2014. Randomized, acute phase, and double-blind studies comparing an antidepressant group with a placebo group in depressed elderly patients were included.

RESULTS

Nineteen studies met all inclusion criteria. Within-group effect sizes revealed significant improvement in antidepressant groups (g=1.35, p<.000), as well as in placebo groups (g=.96, p<.000). Change in depressive symptoms assessed by Hamilton Depression Rating Scale (HDRS) was moderated by baseline severity in antidepressant groups (Z=2.67, p=.008) and placebo groups (Z=4.46, p<.000). However, this would be expected as a result of regression toward the mean, and mean differences between groups did not increase (r=.19, p=.469) as a function of baseline severity.

LIMITATIONS

Limited to published data and information was only analyzed at the level of treatment groups.

CONCLUSION

Baseline severity was not associated with an antidepressant-placebo difference and placebo responses are large in the treatment of depressed elderly people. We propose a stepwise approach, i.e., to initially offer elderly depressed patients psychosocial interventions and only consider antidepressants if patients do not respond.

The medical alliance: from placebo response to alliance effect

The natural human response to illness is to seek to understand what is happening and to look for help from others. In all cultures, one finds healers, who provide explanations and offer care. Their interventions often have a placebo effect through activation of natural healing processes in the patient. Although placebo effects are relatively large and robust, physicians generally consider placebo treatment prescientific and deceptive. We review the determinants of the placebo response and show how a particular professional alliance between a patient and a caregiver is apt to equally affect treatment outcome. We distinguish the alliance effect from the placebo effect. We develop a comprehensive model of the medical alliance, on the basis of the concept of concordance, and review its relevance for clinical practice and medical education. The alliance effect represents a professional and ethical way of activating a patient's natural healing mechanisms.

Nutmeg extracts for painful diabetic neuropathy: a randomized, double-blind, controlled study

OBJECTIVES

Current treatment strategies for painful diabetic neuropathy (PDN) include oral medications, which are costly and may have adverse effects. Topical therapies have been used for PDN with some benefit. Nutmeg has certain properties that may be effective in ameliorating neuropathic pain. The purpose of this study was to determine whether topical nutmeg extracts can reduce pain or improve the quality of life in PDN sufferers.

DESIGN

This study was a randomized, double-blind, placebo-controlled trial.

SETTINGS/LOCATION

It was conducted at a primary care center in Trinidad, Caribbean.

SUBJECTS

Seventy-four (74) diabetic subjects who met criteria for painful neuropathy were recruited.

INTERVENTIONS

Participants were randomized to receive either topical nutmeg extracts (NEMM; mace oil [2%], nutmeg oil [14%], methyl salicylate [6%], menthol [6%], and coconut oil) or placebo (MM; methyl salicylate [6%], menthol [6%], coconut oil, and alcohol).

OUTCOME MEASURES

Outcome measures of pain and quality of life were assessed using the Brief Pain Inventory for Diabetic Painful Neuropathy and Neuropathic Pain Symptom Inventory.

RESULTS

An intention-to-treat analysis was done for 24 male and 50 female subjects (30-85 years) with an average duration of diabetes of 11 years. Significant reductions in worst and average pain scores were seen within each group (p ≤ 0.001). Similarly significant reductions were also noted for interference with walking, sleep, and mood scores as well as burning, pins and needles, and tingling scores within each group (p<0.05). There were no statistically significant differences between both groups after 4 weeks for any outcome measure.

CONCLUSIONS

In this trial topical, nutmeg extracts did not add to the improvements observed in PDN symptoms during 4 weeks treatment with preparations containing menthol and methyl salicylate. Further research designed to test the individual components of the topical therapies used in this study may clarify their benefit.

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.