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Question Tricyclic antidepressants are used to treat depression worldwide, but the adverse effects have not been systematically assessed. Our objective was to assess the beneficial and harmful effects of all tricyclic antidepressants for adults with major depressive disorder.Study selection and analysis We conducted a systematic review with meta-analysis and trial sequential analysis. We searched CENTRAL, MEDLINE, Embase, LILACS and other sources from inception to January 2023 for randomised clinical trials comparing tricyclic antidepressants versus placebo or ‘active placebo’ for adults with major depressive disorder. The primary outcomes were depressive symptoms measured on the 17-item Hamilton Depression Rating Scale (HDRS-17), serious adverse events and quality of life. The minimal important difference was defined as three points on the HDRS-17.Findings We included 103 trials randomising 10 590 participants. All results were at high risk of bias, and the certainty of the evidence was very low or low. All trials only assessed outcomes at the end of the treatment period at a maximum of 12 weeks after randomisation. Meta-analysis and trial sequential analysis showed evidence of a beneficial effect of tricyclic antidepressants compared with placebo (mean difference −3.77 HDRS-17 points; 95% CI −5.91 to −1.63; 17 trials). Meta-analysis showed evidence of a harmful effect of tricyclic antidepressants compared with placebo on serious adverse events (OR 2.78; 95% CI 2.18 to 3.55; 35 trials), but the required information size was not reached. Only 2 out of 103 trials reported on quality of life and t-tests showed no evidence of a difference.Conclusions The long-term effects of tricyclic antidepressants and the effects on quality of life are unknown. Short-term results suggest that tricyclic antidepressants may reduce depressive symptoms while also increasing the risks of serious adverse events, but these results were based on low and very low certainty evidence.PROSPERO registration number CRD42021226161.

Abstract Background Major depressive disorder causes a great burden on patients and societies. Venlafaxine and mirtazapine are commonly prescribed as second-line treatment for patients with major depressive disorder worldwide. Previous systematic reviews have concluded that venlafaxine and mirtazapine reduce depressive symptoms, but the effects seem small and may not be important to the average patient. Moreover, previous reviews have not systematically assessed the occurrence of adverse events. Therefore, we aim to investigate the risks of adverse events with venlafaxine or mirtazapine versus ‘active placebo’, placebo, or no intervention for adults with major depressive disorder in two separate systematic reviews. Methods This is a protocol for two systematic reviews with meta-analysis and Trial Sequential Analysis. The assessments of the effects of venlafaxine or mirtazapine will be reported in two separate reviews. The protocol is reported as recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols, risk of bias will be assessed with the Cochrane risk-of-bias tool version 2, clinical significance will be assessed using our eight-step procedure, and the certainty of the evidence will be assessed with the Grading of Recommendations Assessment, Development and Evaluation approach. We will search for published and unpublished trials in major medical databases and trial registers. Two review authors will independently screen the results from the literature searches, extract data, and assess risk of bias. We will include published or unpublished randomised clinical trial comparing venlafaxine or mirtazapine with ‘active placebo’, placebo, or no intervention for adults with major depressive disorder. The primary outcomes will be suicides or suicide attempts, serious adverse events, and non-serious adverse events. Exploratory outcomes will include depressive symptoms, quality of life, and individual adverse events. If feasible, we will assess the intervention effects using random-effects and fixed-effect meta-analyses. Discussion Venlafaxine and mirtazapine are frequently used as second-line treatment of major depressive disorder worldwide. There is a need for a thorough systematic review to provide the necessary background for weighing the benefits against the harms. This review will ultimately inform best practice in the treatment of major depressive disorder. Systematic review registration PROSPERO CRD42022315395.

Abstract Placebos have been shown to be beneficial for various conditions even if administered with full transparency. Hence, so-called open-label placebos (OLPs) offer a new way to harness placebo effects ethically. To take this concept one step further, this study aimed at evaluating placebo effects without the use of a physical placebo, i.e., by imagining taking a pill. Healthy students (N = 173) with self-reported test anxiety were either randomized to an imaginary pill (IP; n = 55), an OLP (n = 59) or a control group (CG; n = 59). Both intervention groups were instructed to take two pills daily for three weeks. Primary outcome was test anxiety, secondary outcomes were sleep quality, general well-being and test performance. Groups test anxiety differed at study-endpoint, F(2,169) = 11.50, p

Objective Reanalyse the patient-level data set of the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study with fidelity to the original research protocol and related publications.Design The study was open label and semirandomised examining the effectiveness of up to four optimised and increasingly aggressive, antidepressant therapies in depressed adults. Patients who failed to gain adequate relief from their level 1 trial on the SSRI citalopram could receive up to three additional treatment trials in levels 2–4.Setting 41 North American psychiatry and primary care treatment centres.Participants 4041 adults screened positive for major depressive disorder. In contrast to most clinical trials, STAR*D enrolled patients seeking care (vs recruited) and included patients with a wide range of common comorbid medical and psychiatric conditions to enhance the generalisability of findings to real-world clinical practice.Interventions STAR*D evaluated the relative effectiveness of 13 antidepressants therapies in treatment levels 2–4 for depressed patients who failed to gain adequate benefit from their level 1 medication trial.Main outcome measures According to the STAR*D protocol, the primary outcome was remission, defined as a score

Background The efficacy of open-label placebos (OLPs) has been increasingly demonstrated and their use holds promise for applications compatible with basic ethical principles. Taking this concept one step further an imaginary pill (IP) intervention without the use of a physical pill was developed and tested in a randomized controlled trial (RCT). To explore participants’ experiences and views, we conducted the first qualitative study in the field of IPs. Methods A reflexive thematic analysis (RTA) of semi-structured interviews with test anxious students (N = 20) was nested in an RCT investigating an IP and OLP intervention. In addition, open-ended questions from the RCT were evaluated (N = 114) to corroborate the RTA and pill characteristics were included to more accurately capture the IP experience. Results Four key themes were identified: (1) attitude towards the intervention, (2) applicability of the intervention, (3) experience of effects, and (4) characteristics of the imagination. The IP intervention was well-accepted, easily applicable, and various effects, pill characteristics and appearances were described. While many participants did not desire a physical pill, either due to the absence of the imagination component or aversion to pills, the approach was considered to be cognitively and time demanding, which in turn, however, encouraged the establishment of a therapeutic ritual that protected against the increase in test anxiety during the preparation phase. OLP findings were comparable, and especially the importance of a treatment rationale was stressed in both groups, counteracting an initial ambivalent attitude. The RTA findings were supported by the open-ended questions of the RCT. Conclusion IPs appear to be a well-accepted and easily applicable intervention producing a variety of beneficial effects. Thus, the IP approach might serve as an imaginary based alternative to OLPs warranting further investigations on its application to harness placebo effects without a physical pill.

Abstract Patient–clinician concordance in behavior and brain activity has been proposed as a potential key mediator of mutual empathy and clinical rapport in the therapeutic encounter. However, the specific elements of patient–clinician communication that may support brain-to-brain concordance and therapeutic alliance are unknown. Here, we investigated how pain-related, directional facial communication between patients and clinicians is associated with brain-to-brain concordance. Patient–clinician dyads interacted in a pain-treatment context, during synchronous assessment of brain activity (fMRI hyperscanning) and online video transfer, enabling face-to-face social interaction. In-scanner videos were used for automated individual facial action unit (AU) time-series extraction. First, an interpretable machine-learning classifier of patients’ facial expressions, from an independent fMRI experiment, significantly distinguished moderately painful leg pressure from innocuous pressure stimuli. Next, we estimated neural-network causality of patient-to-clinician directional information flow of facial expressions during clinician-initiated treatment of patients’ evoked pain. We identified a leader–follower relationship in which patients predominantly led the facial communication while clinicians responded to patients’ expressions. Finally, analyses of dynamic brain-to-brain concordance showed that patients’ mid/posterior insular concordance with the clinicians’ anterior insula cortex, a region identified in previously published data from this study1, was associated with therapeutic alliance, and self-reported and objective (patient-to-clinician-directed causal influence) markers of negative-affect expressivity. These results suggest a role of patient-clinician concordance of the insula, a social-mirroring and salience-processing brain node, in mediating directional dynamics of pain-directed facial communication during therapeutic encounters.

Abstract Background Major depressive disorder is a common psychiatric disorder causing great burden on patients and societies. Tricyclic antidepressants are frequently used worldwide to treat patients with major depressive disorder. It has repeatedly been shown that tricyclic antidepressants reduce depressive symptoms with a statistically significant effect, but the effect is small and of questionable clinical importance. Moreover, the beneficial and harmful effects of all types of tricyclic antidepressants have not previously been systematically assessed. Therefore, we aim to investigate the beneficial and harmful effects of tricyclic antidepressants versus ‘active placebo’, placebo or no intervention for adults with major depressive disorder. Methods This is a protocol for a systematic review with meta-analysis that will be reported as recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols, bias will be assessed with the Cochrane Risk of Bias tool—version 2, our eight-step procedure will be used to assess if the thresholds for clinical significance are crossed, Trial Sequential Analysis will be conducted to control random errors and the certainty of the evidence will be assessed with the Grading of Recommendations Assessment, Development and Evaluation approach. To identify relevant trials, we will search both for published and unpublished trials in major medical databases and trial registers, such as CENTRAL, MEDLINE, EMBASE and ClinicalTrials.gov from their inception to 12 May 2021. Clinical study reports will be applied for from regulatory authorities and pharmaceutical companies. Two review authors will independently screen the results from the literature searches, extract data and perform risk of bias assessment. We will include any published or unpublished randomised clinical trial comparing tricyclic antidepressants with ‘active placebo’, placebo or no intervention for adults with major depressive disorder. The following interventions will be assessed: amineptine, amitriptyline, amoxapine, butriptyline, cianopramine, clomipramine, desipramine, demexiptiline, dibenzepin, dosulepin, dothiepin, doxepin, imipramine, iprindole, lofepramine, maprotiline, melitracen, metapramine, nortriptyline, noxiptiline, opipramol, protriptyline, tianeptine, trimipramine and quinupramine. Primary outcomes will be depressive symptoms, serious adverse events and quality of life. Secondary outcomes will be suicide or suicide-attempts and non-serious adverse events. If feasible, we will assess the intervention effects using random-effects and fixed-effect meta-analyses. Discussion Tricyclic antidepressants are recommended by clinical guidelines and frequently used worldwide in the treatment of major depressive disorder. There is a need for a thorough systematic review to provide the necessary background for weighing the benefits against the harms. This review will ultimately inform best practice in the treatment of major depressive disorder. Systematic review registration PROSPERO CRD42021226161 .

In placebo research, expectations are highlighted as one of the most influential subjective factors. While some studies have shown a relationship between expectations and pain relief, others have not. However, little is known about how methods of assessment of expectations may affect these conclusions. One of the fundamental considerations is that participants in placebo trials rate their expectations when prompted to rate them on scales in advance, but are less likely to report their prior expectations, when asked to report their experience retroactively in an unprompted manner, often expressing, for example, prior hope or wishes of recovery. This article presents previously unpublished data to elucidate and explore the concepts highlighted by individuals in a placebo analgesia trial when assessed in a prompted and unprompted manner. The data corroborates the role of expectations involved in placebo effects, particularly in placebo analgesia. Thus, the question may be a matter of how and when expectations contribute to placebo effects, rather than if.

Abstract Background Major depressive disorder is one of the most common, burdensome, and costly psychiatric disorders worldwide. Antidepressants are frequently used to treat major depressive disorder. It has been shown repeatedly that antidepressants seem to reduce depressive symptoms with a statistically significant effect, but the clinical importance of the effect sizes seems questionable. Both beneficial and harmful effects of antidepressants have not previously been sufficiently assessed. The main objective of this review will be to evaluate the beneficial and harmful effects of antidepressants versus placebo, ‘active placebo’, or no intervention for adults with major depressive disorder. Methods/design A systematic review with meta-analysis will be reported as recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), bias will be assessed with the Cochrane Risk of Bias tool-version 2 (ROB2), our eight-step procedure will be used to assess if the thresholds for clinical significance are crossed, Trial Sequential Analysis will be conducted to control for random errors, and the certainty of the evidence will be assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. To identify relevant trials, we will search both for published and unpublished trials in major medical databases from their inception to the present. Clinical study reports will be obtained from regulatory authorities and pharmaceutical companies. Two review authors will independently screen the results of the literature searches, extract data, and perform risk of bias assessment. We will include any published or unpublished randomised clinical trial comparing one or more antidepressants with placebo, ‘active placebo’, or no intervention for adults with major depressive disorder. The following active agents will be included: agomelatine, amineptine, amitriptyline, bupropion, butriptyline, cianopramine, citalopram, clomipramine, dapoxetine, demexiptiline, desipramine, desvenlafaxine, dibenzepin, dosulepin, dothiepin, doxepin, duloxetine, escitalopram, fluoxetine, fluvoxamine, imipramine, iprindole, levomilnacipran, lofepramine, maprotiline, melitracen, metapramine, milnacipran, mirtazapine, nefazodone, nortriptyline, noxiptiline, opipramol, paroxetine, protriptyline, quinupramine, reboxetine, sertraline, trazodone, tianeptine, trimipramine, venlafaxine, vilazodone, and vortioxetine. Primary outcomes will be depressive symptoms, serious adverse events, and quality of life. Secondary outcomes will be suicide or suicide attempt, suicidal ideation, and non-serious adverse events. Discussion As antidepressants are commonly used to treat major depressive disorder in adults, a systematic review evaluating their beneficial and harmful effects is urgently needed. This review will inform best practice in treatment and clinical research of this highly prevalent and burdensome disorder. Systematic review registration PROSPERO CRD42020220279

Music interventions accommodate the profound need for non-pharmacological pain treatment. The analgesic effect of listening to music has been widely demonstrated across studies. Yet, the specific mechanisms of action have still to be elucidated. Although the endogenous opioid and dopamine systems have been suggested to play an important role, a direct link has not been established. In addition, the involvement of placebo mechanisms is likely while largely unexplored. We examined the analgesic effect of music in healthy participants (n = 48) using a 3 × 3 within-subjects design with pharmacological manipulations and a matched, auditory control for music. Participants were exposed to thermal pain stimuli while listening to three auditory excerpts: music (active condition), nature sound (matched, auditory contextual condition), and noise (neutral control condition). The participants rated their expected and perceived pain levels in relation to each of the auditory excerpts. To investigate the involvement of the endogenous opioid and dopamine systems, the test session was performed three times on separate days featuring a double-blind randomized oral administration of naltrexone (opioid antagonist), haloperidol (dopamine antagonist), and an inactive agent (control). Our results support an analgesic effect of music. Contrary to current hypotheses, neither of the antagonists attenuated the effect of music. Yet, the participants' expectations for pain relief predicted their perceived pain levels during the auditory excerpts—even when controlling for a gradual learning effect. In conclusion, we demonstrate that the analgesic effect of music is at least partially mediated by expectations of an analgesic effect—a core mechanism in placebo effects—but not by opioid and dopamine-dependent mechanisms.Clinical Trial Registrationwww.clinicaltrials.gov, identifier: NCT03410563.

Abstract Background and aim Despite recent publications, practitioners remain unfamiliar with the current terminology related to the placebo and nocebo phenomena observed in clinical trials and practice, nor with the factors that modulate them. To cover the gap, the European Headache Federation appointed a panel of experts to clarify the terms associated with the use of placebo in clinical trials. Methods The working group identified relevant questions and agreed upon recommendations. Because no data were required to answer the questions, the GRADE approach was not applicable, and thus only expert opinion was provided according to an amended Delphi method. The initial 12 topics for discussion were revised in the opinion of the majority of the panelists, and after a total of 6 rounds of negotiations, the final agreement is presented. Results/recommendations Two primary and mechanism-based recommendations are provided for the results of clinical trials: [1] to distinguish the placebo or nocebo response from the placebo or nocebo effect; and [2] for any favorable outcome observed after placebo administration, the term “placebo response” should be used, and for any unfavorable outcome recorded after placebo administration, the term “nocebo response” should be used (12 out of 17 panelists agreed, 70.6% agreement). The placebo or nocebo responses are attributed to a set of factors including those that are related to the medical condition (e.g. natural history, random comorbidities, etc.), along with idiosyncratic ones, in which the placebo or nocebo effects are attributed to idiosyncratic, or nonspecific mechanisms, exclusively (e.g. expectation, conditioning, observational learning etc.). To help investigators and practitioners, the panel summarized a list of environmental factors and idiosyncratic dynamics modulating placebo and nocebo effects. Some of them are modifiable, and investigators or physicians need to know about them in order to modify these factors appropriately to improve treatment. One secondary recommendation addresses the use of the terms “placebo” and “nocebo” (“placebos” and “nocebos” in plural), which refer to the triggers of the placebo/nocebo effects or responses, respectively, and which are inert agents or interventions that should not be confused with the placebo/nocebo responses or effects themselves (all panelists agreed, 100% agreement). Conclusion The working group recommends distinguishing the term response from effect to describe health changes from before to after placebo application and to distinguish the terms placebo(s) or nocebo(s) from the health consequences that they cause (placebo/nocebo responses or effects).

BackgroundPlacebos can reduce physical symptoms even when provided with full honesty and disclosure. Yet, the precise mechanisms underlying the effects of "open-label placebos" (OLPs) have remained subject of debate. Furthermore, it is unclear whether OLPs are similarly effective when provided remotely, as is sometimes required e.g. in the current COVID-19 pandemic.MethodsIn a randomized-controlled trial, we examined the effects of OLP plus treatment as usual (TAU) compared to TAU alone on symptom reduction in people with allergic rhinitis (N = 54) over the course of two weeks. Due to the COVID-19 pandemic, OLP was provided remotely (i.e. sent via postal service). To investigate the potential influence of the clinical encounter on the effects of OLP, we manipulated the perception of the virtual clinical encounter, both with respect to verbal and nonverbal factors (augmented vs. limited encounter).ResultsThe results of the manipulation check confirmed that the augmented clinical encounter was evaluated more positively than the limited encounter, in terms of perceived warmth of the provider. Participants from all treatment groups showed significant symptom reduction from baseline to two weeks later, but OLP had no incremental effect over TAU. Participants benefitted more from OLP when they did not take any other medication against allergic symptoms than when taking medication on demand. When controlling for baseline symptoms, a significant treatment by encounter interaction was found, pointing to greater symptom improvement in the OLP group when the encounter was augmented, whereas the control group improved more when the encounter was limited.DiscussionThe study demonstrates that providing OLP and enhancing the encounter remotely is possible, but their effectiveness might be lower in comparison to previous studies relying on physical patient-provider interaction. The study raises questions for future research about the potential and challenges of remote placebo studies and virtual clinical encounters. The study has been registered as a clinical trial at ISRCTN (record number: 39018).

[This corrects the article DOI: 10.1371/journal.pone.0248367.].

This article explores the reaction when an article challenging received wisdom is published and covered extensively by the media (1). The article in question was a meta-analysis of antidepressant clinical trials indicating that for most patients, difference between drug and placebo was not clinically significant. Reactions ranged from denial that the effects of antidepressants are so small to criticisms of the clinical trials that were analyzed. Each of these reactions is explored and countered.

IntroductionRecent evidence suggests that for certain clinical conditions, placebos can improve clinical outcomes even without deception. These so-called open-label placebos (OLPs) bear the advantage of a significant lower risk of adverse events and comply with ethical principles. Although premenstrual syndrome (PMS) seems to be considerably susceptible to placebo effects, no study has examined open-OLP responses on PMS.Methods and analysisTo test the efficacy of OLPs in women suffering from PMS, a clinical randomised controlled trial including two OLP study groups (with and without treatment rationale) was designed to investigate on the effect on PMS. PMS symptoms are monitored on a daily basis via a symptom diary, adverse events are monitored intermittently. The study started in spring 2018 and patients will be included until a maximum of 150 participants are randomised. Besides the primary outcome PMS symptom intensity and interference, an array of further variables is assessed. Multilevel modelling will be used for data analyses.Ethics and disseminationEthics approval was obtained from the Ethics Committee Northwest and Central Switzerland. Results of the main analysis and of secondary analyses will be submitted for publication in peer-reviewed journals.Trial registration numbers(1) ClinicalTrials.gov (NCT03547661); (2) Swiss national registration (SNCTP000002809).

Objectives: Expectation can significantly modulate pain and treatment effects. This study aims to investigate if boosting patients' expectancy can enhance the treatment of knee osteoarthritis (KOA), and its underlying brain mechanism. Methods: Seventy-four KOA patients were recruited and randomized to three groups: boosted acupuncture (with a manipulation to enhance expectation), standard acupuncture, or treatment as usual (TAU). Each patient underwent six treatments before being debriefed, and four additional treatments after being debriefed. The fMRI scans were applied during the first and sixth treatment sessions. Results: We found significantly decreased knee pain in the boosted acupuncture group compared to the standard acupuncture or TAU groups after both six and ten treatments. Resting state functional connectivity (rsFC) analyses using the nucleus accumbens (NAc) as the seed showed rsFC increases between the NAc and the medial prefrontal cortex (MPFC)/rostral anterior cingulate cortex (rACC) and dorsolateral prefrontal cortex in the boosted group as compared to the standard acupuncture group after multiple treatments. Expectancy scores after the first treatment were significantly associated with increased NAc-rACC/MPFC rsFC and decreased knee pain following treatment. Conclusions: Our study provides a novel method and mechanism for boosting the treatment of pain in patients with KOA. Our findings may shed light on enhancing outcomes of pharmacological and integrative medicines in clinical settings. Keywords: Knee osteoarthritis, Expectancy, Acupuncture, Reward, Resting state functional connectivity

Abstract Background Placebo medications, by definition, are composed of inactive ingredients that have no physiological effect on symptoms. Nonetheless, administration of placebo in randomized controlled trials (RCTs) and in clinical settings has been demonstrated to have significant impact on many physical and psychological complaints. Until recently, conventional wisdom has suggested that patients must believe that placebo pills actually contain (or, at least, might possibly contain) active medication in order to elicit a response to placebo. However, several recent RCTs, including patients with irritable bowel syndrome (IBS), chronic low back pain, and episodic migraine, have demonstrated that individuals receiving open-label placebo (OLP) can still experience symptomatic improvement and benefit from honestly described placebo treatment. Methods and design This paper describes an innovative multidisciplinary trial design (n = 280) that attempts to replicate and expand upon an earlier IBS OLP study. The current study will compare OLP to double-blind placebo (DBP) administration which is made possible by including a nested, double-blind RCT comparing DBP and peppermint oil. The study also examines possible genetic and psychological predictors of OLP and seeks to better understand participants’ experiences with OLP and DBP through a series of extensive interviews with a randomly selected subgroup. Discussion OLP treatment is a novel strategy for ethically harnessing placebo effects. It has potential to re-frame theories of placebo and to influence how physicians can optimize watch-and-wait strategies for common, subjective symptoms. The current study aims to dramatically expand what we know about OLP by comparing, for the first time, OLP and DBP administration. Adopting a unique, multidisciplinary approach, the study also explores genetic, psychological and experiential dimensions of OLP. The paper ends with an extensive discussion of the “culture” of the trial as well as potential mechanisms of OLP and ethical implications. Trial registration ClinicalTrials.gov, identifier: NCT02802241 . Registered on 14 June 2016.

The aim of this review is to evaluate the placebo effect in the treatment of anxiety and depression. Antidepressants are supposed to work by fixing a chemical imbalance, specifically, a lack of serotonin or norepinephrine in the brain. However, analyses of the published and the unpublished clinical trial data are consistent in showing that most (if not all) of the benefits of antidepressants in the treatment of depression and anxiety are due to the placebo response, and the difference in improvement between drug and placebo is not clinically meaningful and may be due to breaking blind by both patients and clinicians. Although this conclusion has been the subject of intense controversy, the current article indicates that the data from all of the published meta-analyses report the same results. This is also true of recent meta-analysis of all of the antidepressant data submitted to the Food and Drug Administration (FDA) in the process of seeking drug approval. Also, contrary to previously published results, the new FDA analysis reveals that the placebo response has not increased over time. Other treatments (e.g., psychotherapy and physical exercise) produce the same benefits as antidepressants and do so without the side effects and health risks of the active drugs. Psychotherapy and placebo treatments also show a lower relapse rate than that reported for antidepressant medication.

Side effects are frequent in pharmacological pain management, potentially preceding analgesia and limiting drug tolerability. Discussing side effects is part of informed consent, yet can favor nocebo effects. This study aimed to test whether a positive suggestion regarding side effects, which could act as reminders of the medication having been absorbed, might favor analgesia in a clinical interaction model. Sixty-six healthy males participated in a study "to validate pupillometry as an objective measure of analgesia". Participants were unknowingly randomized double-blind to positive vs control information about side effects embedded in a video regarding the study drugs. Sequences of moderately painful heat stimuli applied before and after treatment with diclofenac and atropine served to evaluate analgesia. Atropine was deceptively presented as a co-analgesic, but used to induce side effects. Adverse events (AE) were collected with the General Assessment of Side Effects (GASE) questionnaire prior to the second induced pain sequence. Debriefing fully informed participants regarding the purpose of the study and showed them the two videos.The combination of medication led to significant analgesia, without a between-group difference. Positive information about side effects increased the attribution of AE to the treatment compared to the control information. The total GASE score was correlated with analgesia, i.e., the more AEs reported, the stronger the analgesia. Interestingly, there was a significant between-groups difference on this correlation: the GASE score and analgesia correlated only in the positive information group. This provides evidence for a selective link between AEs and pain relief in the group who received the suggestion that AEs could be taken as a sign "that help was on the way". During debriefing, 65% of participants said they would prefer to receive the positive message in a clinical context. Although the present results cannot be translated immediately to clinical pain conditions, they do indicate the importance of testing this type of modulation in a clinical context.

Genetically determined Intellectual Disability (ID) is an intractable condition that involves severe impairment of mental abilities such as learning, reasoning and predicting the future. As of today, little is known about the placebo response in patients with ID.To determine if placebo response exists in patients with genetically determined ID.We searched Medline/PubMed, EMBASE, CENTRAL and PsycINFO to find all placebo-controlled double-blind randomized clinical trials (RCTs) in patients with genetically determined ID, published up to April 2013, focusing on core ID symptoms.Two investigators extracted outcome data independently.Bias-corrected standardized mean difference (Hedge's g) was computed for each outcome measure, using the Comprehensive Meta-Analysis software. A priori defined patient sub-groups were analyzed using a mixed-effect model. The relationship between pre-defined continuous variable moderators (age, IQ, year of publication and trial duration) and effect size was analyzed using meta-regression.Twenty-two placebo-controlled double-blind RCTs met the inclusion criteria (n = 721, mean age = 17.1 years, 62% men, mean trial duration = 35 weeks). There was a significant overall placebo response from pre- to post-treatment in patients with ID (g = 0.468, p = 0.002), both for "subjective outcomes" (a third-person's evaluation of the patient) (g = 0.563, p = 0.022) and "objective outcomes" (direct evaluation of the patient's abilities) (g = 0.434, p = 0.036). Individuals with higher IQ had higher response to placebo (p = 0.02) and no placebo response was observed in ID patients with comorbid dementia. A significant effect of age (p = 0.02) was found, indicating higher placebo responses in treatment of younger patients.Results suggest that patients with genetically determined ID improve in the placebo arm of RCTs. Several mechanisms may contribute to placebo effects in ID, including expectancy, implicit learning and "placebo-by-proxy" induced by clinicians/family members. As the condition is refractory, there is little risk that improvements are explained by spontaneous remission. While new avenues for treatment of genetically determined ID are emerging, our results demonstrate how contextual factors can affect clinical outcomes and emphasize the importance of being vigilant on the role of placebos when testing novel treatments in ID.

Music has pain-relieving effects, but its mechanisms remain unclear. We sought to verify previously studied analgesic components and further elucidate the underpinnings of music analgesia. Using a well-characterized conditioning-enhanced placebo model, we examined whether boosting expectations would enhance or interfere with analgesia from strongly preferred music. A two-session experiment was performed with 48 healthy, pain experiment-naïve participants. In a first cohort, 36 were randomized into 3 treatment groups, including music enhanced with positive expectancy, non-musical sound enhanced with positive expectancy, and no expectancy enhancement. A separate replication cohort of 12 participants received only expectancy-enhanced music following the main experiment to verify the results of expectancy-manipulation on music. Primary outcome measures included the change in subjective pain ratings to calibrated experimental noxious heat stimuli, as well as changes in treatment expectations. Without conditioning, expectations were strongly in favor of music compared to non-musical sound. While measured expectations were enhanced by conditioning, this failed to affect either music or sound analgesia significantly. Strongly preferred music on its own was as pain relieving as conditioning-enhanced strongly preferred music, and more analgesic than enhanced sound. Our results demonstrate the pain-relieving power of personal music even over enhanced expectations.Clinicaltrials.gov NCT01835275.

BACKGROUND:Previous meta-analyses of published and unpublished trials indicate that antidepressants provide modest benefits compared to placebo in the treatment of depression; some have argued that these benefits are not clinically significant. However, these meta-analyses were based only on trials submitted for the initial FDA approval of the medication and were limited to those aimed at treating depression. Here, for the first time, we assess the efficacy of a selective serotonin reuptake inhibitor (SSRI) in the treatment of both anxiety and depression, using a complete data set of all published and unpublished trials sponsored by the manufacturer. METHODS AND FINDINGS:GlaxoSmithKline has been required to post the results for all sponsored clinical trials online, providing an opportunity to assess the efficacy of an SSRI (paroxetine) with a complete data set of all trials conducted. We examined the data from all placebo-controlled, double-blind trials of paroxetine that included change scores on the Hamilton Rating Scale for Anxiety (HRSA) and/or the Hamilton Rating Scale for Depression (HRSD). For the treatment of anxiety (k = 12), the efficacy difference between paroxetine and placebo was modest (d = 0.27), and independent of baseline severity of anxiety. Overall change in placebo-treated individuals replicated 79% of the magnitude of paroxetine response. Efficacy was superior for the treatment of panic disorder (d = 0.36) than for generalized anxiety disorder (d = 0.20). Published trials showed significantly larger drug-placebo differences than unpublished trials (d's = 0.32 and 0.17, respectively). In depression trials (k = 27), the benefit of paroxetine over placebo was consistent with previous meta-analyses of antidepressant efficacy (d = 0.32). CONCLUSIONS:The available empirical evidence indicates that paroxetine provides only a modest advantage over placebo in treatment of anxiety and depression. Treatment implications are discussed.

Placebo treatments and healing rituals have been used to treat pain throughout history. The present within-subject crossover study examines the variability in individual responses to placebo treatment with verbal suggestion and visual cue conditioning by investigating whether responses to different types of placebo treatment, as well as conditioning responses, correlate with one another. Secondarily, this study also examines whether responses to sham acupuncture correlate with responses to genuine acupuncture. Healthy subjects were recruited to participate in two sequential experiments. Experiment one is a five-session crossover study. In each session, subjects received one of four treatments: placebo pills (described as Tylenol), sham acupuncture, genuine acupuncture, or no treatment rest control condition. Before and after each treatment, paired with a verbal suggestion of positive effect, each subject's pain threshold, pain tolerance, and pain ratings to calibrated heat pain were measured. At least 14 days after completing experiment one, all subjects were invited to participate in experiment two, during which their analgesic responses to conditioned visual cues were tested. Forty-eight healthy subjects completed experiment one, and 45 completed experiment two. The results showed significantly different effects of genuine acupuncture, placebo pill and rest control on pain threshold. There was no significant association between placebo pills, sham acupuncture and cue conditioning effects, indicating that individuals may respond to unique healing rituals in different ways. This outcome suggests that placebo response may be a complex behavioral phenomenon that has properties that comprise a state, rather than a trait characteristic. This could explain the difficulty of detecting a signature for "placebo responders." However, a significant association was found between the genuine and sham acupuncture treatments, implying that the non-specific effects of acupuncture may contribute to the analgesic effect observed in genuine acupuncture analgesia.

BackgroundAlthough previous meta-analyses have examined effects of antidepressants, psychotherapy, and alternative therapies for depression, the efficacy of these treatments alone and in combination has not been systematically compared. We hypothesized that the differences between approved depression treatments and controls would be small.Methods and findingsThe authors first reviewed data from Food and Drug Administration Summary Basis of Approval reports of 62 pivotal antidepressant trials consisting of data from 13,802 depressed patients. This was followed by a systematic review of data from 115 published trials evaluating efficacy of psychotherapies and alternative therapies for depression. The published depression trials consisted of 10,310 depressed patients. We assessed the percentage symptom reduction experienced by the patients based on treatment assignment. Overall, antidepressants led to greater symptom reduction compared to placebo among both unpublished FDA data and published trials (F = 38.5, df = 239, pConclusionsIn conclusion, the combination of psychotherapy and antidepressants for depression may provide a slight advantage whereas antidepressants alone and psychotherapy alone are not significantly different from alternative therapies or active intervention controls. These data suggest that type of treatment offered is less important than getting depressed patients involved in an active therapeutic program. Future research should consider whether certain patient profiles might justify a specific treatment modality.

Identifying patients who are potential placebo responders has major implications for clinical practice and trial design. Catechol-O-methyltransferase (COMT), an important enzyme in dopamine catabolism plays a key role in processes associated with the placebo effect such as reward, pain, memory and learning. We hypothesized that the COMT functional val158met polymorphism, was a predictor of placebo effects and tested our hypothesis in a subset of 104 patients from a previously reported randomized controlled trial in irritable bowel syndrome (IBS). The three treatment arms from this study were: no-treatment ("waitlist"), placebo treatment alone ("limited") and, placebo treatment "augmented" with a supportive patient-health care provider interaction. The primary outcome measure was change from baseline in IBS-Symptom Severity Scale (IBS-SSS) after three weeks of treatment. In a regression model, the number of methionine alleles in COMT val158met was linearly related to placebo response as measured by changes in IBS-SSS (p = .035). The strongest placebo response occurred in met/met homozygotes treated in the augmented placebo arm. A smaller met/met associated effect was observed with limited placebo treatment and there was no effect in the waitlist control. These data support our hypothesis that the COMT val158met polymorphism is a potential biomarker of placebo response.

Placebo treatment can significantly influence subjective symptoms. However, it is widely believed that response to placebo requires concealment or deception. We tested whether open-label placebo (non-deceptive and non-concealed administration) is superior to a no-treatment control with matched patient-provider interactions in the treatment of irritable bowel syndrome (IBS).Two-group, randomized, controlled three week trial (August 2009-April 2010) conducted at a single academic center, involving 80 primarily female (70%) patients, mean age 47 ± 18 with IBS diagnosed by Rome III criteria and with a score ≥ 150 on the IBS Symptom Severity Scale (IBS-SSS). Patients were randomized to either open-label placebo pills presented as "placebo pills made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes" or no-treatment controls with the same quality of interaction with providers. The primary outcome was IBS Global Improvement Scale (IBS-GIS). Secondary measures were IBS Symptom Severity Scale (IBS-SSS), IBS Adequate Relief (IBS-AR) and IBS Quality of Life (IBS-QoL).Open-label placebo produced significantly higher mean (±SD) global improvement scores (IBS-GIS) at both 11-day midpoint (5.2 ± 1.0 vs. 4.0 ± 1.1, p

BackgroundMeta-analyses of antidepressant medications have reported only modest benefits over placebo treatment, and when unpublished trial data are included, the benefit falls below accepted criteria for clinical significance. Yet, the efficacy of the antidepressants may also depend on the severity of initial depression scores. The purpose of this analysis is to establish the relation of baseline severity and antidepressant efficacy using a relevant dataset of published and unpublished clinical trials.Methods and findingsWe obtained data on all clinical trials submitted to the US Food and Drug Administration (FDA) for the licensing of the four new-generation antidepressants for which full datasets were available. We then used meta-analytic techniques to assess linear and quadratic effects of initial severity on improvement scores for drug and placebo groups and on drug-placebo difference scores. Drug-placebo differences increased as a function of initial severity, rising from virtually no difference at moderate levels of initial depression to a relatively small difference for patients with very severe depression, reaching conventional criteria for clinical significance only for patients at the upper end of the very severely depressed category. Meta-regression analyses indicated that the relation of baseline severity and improvement was curvilinear in drug groups and showed a strong, negative linear component in placebo groups.ConclusionsDrug-placebo differences in antidepressant efficacy increase as a function of baseline severity, but are relatively small even for severely depressed patients. The relationship between initial severity and antidepressant efficacy is attributable to decreased responsiveness to placebo among very severely depressed patients, rather than to increased responsiveness to medication.