How sound is the double-blind design for evaluating psychotropic drugs?

Distinguishing Immunologic and Behavioral Effects of Vaccination

The interpretation of vaccine efficacy estimands is subtle, even in randomized trials designed to quantify the immunologic effects of vaccination. In this article, we introduce terminology to distinguish between different vaccine efficacy estimands and clarify their interpretations. This allows us to explicitly consider the immunologic and behavioral effects of vaccination, and establish that policy-relevant estimands can differ substantially from those commonly reported in vaccine trials. We further show that a conventional vaccine trial allows the identification and estimation of different vaccine estimands under plausible conditions if one additional post-treatment variable is measured. Specifically, we utilize a "belief variable" that indicates the treatment an individual believed they had received. The belief variable is similar to "blinding assessment" variables that are occasionally collected in placebo-controlled trials in other fields. We illustrate the relations between the different estimands, and their practical relevance, in numerical examples based on an influenza vaccine trial.

Great Expectations: recommendations for improving the methodological rigor of psychedelic clinical trials

RATIONALE

Psychedelic research continues to garner significant public and scientific interest with a growing number of clinical studies examining a wide range of conditions and disorders. However, expectancy effects and effective condition masking have been raised as critical limitations to the interpretability of the research.

OBJECTIVE

In this article, we review the many methodological challenges of conducting psychedelic clinical trials and provide recommendations for improving the rigor of future research.

RESULTS

Although some challenges are shared with psychotherapy and pharmacology trials more broadly, psychedelic clinical trials have to contend with several unique sources of potential bias. The subjective effects of a high-dose psychedelic are often so pronounced that it is difficult to mask participants to their treatment condition; the significant hype from positive media coverage on the clinical potential of psychedelics influences participants' expectations for treatment benefit; and participant unmasking and treatment expectations can interact in such a way that makes psychedelic therapy highly susceptible to large placebo and nocebo effects. Specific recommendations to increase the success of masking procedures and reduce the influence of participant expectancies are discussed in the context of study development, participant recruitment and selection, incomplete disclosure of the study design, choice of active placebo condition, as well as the measurement of participant expectations and masking efficacy.

CONCLUSION

Incorporating the recommended design elements is intended to reduce the risk of bias in psychedelic clinical trials and thereby increases the ability to discern treatment-specific effects of psychedelic therapy.

Placebo and Side Effects Confound Clinical Trials on New Antitussives

This review discusses how the placebo effect related to treatment side effects may confound clinical trials on antitussives and specifically looks at the implications for trials on ATP antagonists. These new antitussives have distinctive side effects on the sensation of taste, and investigators have expressed concerns that this may unblind the clinical trials. Blinding is an essential component of trial design, but the degree of blinding in trials is rarely assessed. The assumptions of additivity and balance in clinical trials are discussed as important factors that allow assessment of the pharmacological activity of an antitussive. How side effects unbalance a clinical trial by amplifying the placebo effect of active treatments is discussed. The point is made that unblinding of trials invalidates any assessment of efficacy but that there is little interest or discussion about this fundamental aspect of trials. Proposals are discussed which may improve the blinding of trials and control placebo effects by changes to participant information, trial design, patient selection and use of active placebos. The issue of unblinding of clinical trials is not a new issue, but if real progress is to be made in developing new antitussives, then it is an issue that needs to be urgently addressed.

Comparative efficacy of placebos in short-term antidepressant trials for major depression: a secondary meta-analysis of placebo-controlled trials

BACKGROUND

The issue of unblinded outcome-assessors and patients has repeatedly been stressed as a flaw in allegedly double-blind antidepressant trials. Unblinding bias can for example result from a drug's marked side effects. If such unblinding bias is present for a given drug, then it might be expected that the placebos of that drug are rated significantly less effective than that of other antidepressants.

METHODS

To test this hypothesis, the present exploratory analysis conducted a Bayesian network meta-analysis (NMA) comparing the efficacy of 19 different placebos in placebo-controlled trials provided in the dataset by Cipriani et al. (Lancet 2018; 391: 1357-66). Primary outcome was efficacy (continuous) estimated on the standardized mean difference (SMD) scale and defined as the pre-post change on the Hamilton Depression scale (HAMD-17), on which information was available in N = 258 trials.

RESULTS

Comparative placebo ranking suggested mirtazapine-placebo (SMD -2.0 [- 5.0-1.0 95% CrI]) to be the most, and amitriptyline- (SMD 1.2 [- 1.6-3.9 95% CrI]) and trazodone- (SMD 2.1 [- 0.9-5.2 95% CrI]) placebos to be the least effective placebos. Other placebos suggested to be more effective than amitriptyline- and trazodone-placebos (based on 95% CrIs excluding zero) were citalopram, desvenlafaxine, duloxetine, escitalopram, fluoxetine, sertraline, and venlafaxine placebos. These NMA results were corroborated by the observation that the relative efficacy between drug and placebo was considerably larger for amitriptyline and trazodone than for instance mirtazapine, duloxetine, and venlafaxine, supported by a small and insignificant correlation between drug-efficacy and placebo-efficacy (r = - 0.202, p = 0.408).

DISCUSSION

The present exploratory NMA indicates that distinguishable side effects of older drugs may unblind outcome-assessors thus resulting in overestimation of the average drug-placebo difference and underrating bias in placebo-arms, particularly for the older antidepressant drugs amitriptyline and trazodone. If confirmed in prospective studies, these findings suggest that efficacy rankings for antidepressants are susceptible to bias and should be considered unreliable or misleading. The analysis is limited by the focus on the single-comparison placebos (76%, i.e., placebos assessed in two-arm trials), since double-comparison placebos (25%, i.e., placebos assessed in three-arm trials) are hard to interpret and therefore not included in the present interpretation. Another limitation is the problem of multiplicity, which was only approximately accounted for in the Bayesian NMA by modelling treatment effects as exchangeable.

Benefits and harms of antipsychotic drugs in drug-naïve patients with psychosis: A systematic review

OBJECTIVE

To study the benefits and harms of antipsychotics in drug-naïve patients with psychosis.

METHODS

This study is a systematic review and meta-analysis of placebo-controlled trials.

MAIN OUTCOME MEASURES

Mortality, activities of daily living, quality of life, core psychiatric events, and relapse and recovery rates.

DATA SOURCES

PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), two trial registers and references in potentially eligible articles.

DATA EXTRACTION

Two researchers extracted data independently. The outcomes were planned to be meta-analysed using Review Manager based on a fixed effect model.

RESULTS

Our searches resulted in 493 unique records of which 447 were clearly not eligible. We read the full text of the 46 potentially eligible articles and found one eligible trial in drug-naïve patients, which was unreliable. It was a Chinese trial comparing olanzapine with placebo in 261 patients with first-episode schizophrenia. After 12 weeks, there was an extremely large difference favouring placebo, but the authors reported the opposite, that olanzapine was effective.

CONCLUSIONS

The use of antipsychotics cannot be justified based on the evidence we currently have. Withdrawal effects in the placebo groups make existing placebo-controlled trials unreliable.

Guidelines for the pharmacological acute treatment of major depression: conflicts with current evidence as demonstrated with the German S3-guidelines

Several international guidelines for the acute treatment of moderate to severe unipolar depression recommend a first-line treatment with antidepressants (AD). This is based on the assumption that AD obviously outperform placebo, at least in the case of severe depression. The efficacy of AD for severe depression can only be definitely clarified with individual patient data, but corresponding studies have only been available recently. In this paper, we point out discrepancies between the content of guidelines and the scientific evidence by taking a closer look at the German S3-guidelines for the treatment of depression. Based on recent studies and a systematic review of studies using individual patient data, it turns out that AD are marginally superior to placebo in both moderate and severe depression. The clinical significance of this small drug-placebo-difference is questionable, even in the most severe forms of depression. In addition, the modest efficacy is likely an overestimation of the true efficacy due to systematic method biases. There is no related discussion in the S3-guidelines, despite substantial empirical evidence confirming these biases. In light of recent data and with their underlying biases, the recommendations in the S3-guidelines are in contradiction with the current evidence. The risk-benefit ratio of AD for severe depression may be similar to the one estimated for mild depression and thus could be unfavorable. Downgrading of the related grade of recommendation would be a logical consequence.

Treatment and Prevention of Depression

Depression is one of the most common and debilitating psychiatric disorders and is a leading cause of suicide. Most people who become depressed will have multiple episodes, and some depressions are chronic. Persons with bipolar disorder will also have manic or hypomanic episodes. Given the recurrent nature of the disorder, it is important not just to treat the acute episode, but also to protect against its return and the onset of subsequent episodes.

Several types of interventions have been shown to be efficacious in treating depression. The antidepressant medications are relatively safe and work for many patients, but there is no evidence that they reduce risk of recurrence once their use is terminated. The different medication classes are roughly comparable in efficacy, although some are easier to tolerate than are others. About half of all patients will respond to a given medication, and many of those who do not will respond to some other agent or to a combination of medications. Electro-convulsive therapy is particularly effective for the most severe and resistant depressions, but raises concerns about possible deleterious effects on memory and cognition. It is rarely used until a number of different medications have been tried.

Although it is still unclear whether traditional psychodynamic approaches are effective in treating depression, interpersonal psychotherapy (IPT) has fared well in controlled comparisons with medications and other types of psychotherapies. It also appears to have a delayed effect that improves the quality of social relationships and interpersonal skills. It has been shown to reduce acute distress and to prevent relapse and recurrence so long as it is continued or maintained. Treatment combining IPT with medication retains the quick results of pharmacotherapy and the greater interpersonal breadth of IPT, as well as boosting response in patients who are otherwise more difficult to treat. The main problem is that IPT has only recently entered clinical practice and is not widely available to those in need.

Cognitive behavior therapy (CBT) also appears to be efficacious in treating depression, and recent studies suggest that it can work for even severe depressions in the hands of experienced therapists. Not only can CBT relieve acute distress, but it also appears to reduce risk for the return of symptoms as long as it is continued or maintained. Moreover, it appears to have an enduring effect that reduces risk for relapse or recurrence long after treatment is over. Combined treatment with medication and CBT appears to be as efficacious as treatment with medication alone and to retain the enduring effects of CBT. There also are indications that the same strategies used to reduce risk in psychiatric patients following successful treatment can be used to prevent the initial onset of depression in persons at risk. More purely behavioral interventions have been studied less than the cognitive therapies, but have performed well in recent trials and exhibit many of the benefits of cognitive therapy.

Mood stabilizers like lithium or the anticonvulsants form the core treatment for bipolar disorder, but there is a growing recognition that the outcomes produced by modern pharmacology are not sufficient. Both IPT and CBT show promise as adjuncts to medication with such patients. The same is true for family-focused therapy, which is designed to reduce interpersonal conflict in the family. Clearly, more needs to be done with respect to treatment of the bipolar disorders.

Good medical management of depression can be hard to find, and the empirically supported psychotherapies are still not widely practiced. As a consequence, many patients do not have access to adequate treatment. Moreover, not everyone responds to the existing interventions, and not enough is known about what to do for people who are not helped by treatment. Although great strides have been made over the past few decades, much remains to be done with respect to the treatment of depression and the bipolar disorders.

Active placebo control groups of pharmacological interventions were rarely used but merited serious consideration: a methodological overview

OBJECTIVES

Active placebos are control interventions that mimic the side effects of the experimental interventions in randomized trials and are sometimes used to reduce the risk of unblinding. We wanted to assess how often randomized clinical drug trials use active placebo control groups; to provide a catalog, and a characterization, of such trials; and to analyze methodological arguments for and against the use of active placebo.

STUDY DESIGN AND SETTING

An overview consisting of three thematically linked substudies. In an observational substudy, we assessed the prevalence of active placebo groups based on a random sample of 200 PubMed indexed placebo-controlled randomized drug trials published in October 2013. In a systematic review, we identified and characterized trials with active placebo control groups irrespective of publication time. In a third substudy, we reviewed publications with substantial methodological comments on active placebo groups (searches in PubMed, The Cochrane Library, Google Scholar, and HighWirePress).

RESULTS

The prevalence of trials with active placebo groups published in 2013 was 1 out of 200 (95% confidence interval: 0-2), 0.5% (0-1%). We identified and characterized 89 randomized trials (published 1961-2014) using active placebos, for example, antihistamines, anticholinergic drugs, and sedatives. Such trials typically involved a crossover design, the experimental intervention had noticeable side effects, and the outcomes were patient-reported. The use of active placebos was clustered in specific research settings and did not appear to reflect consistently the side effect profile of the experimental intervention, for example, selective serotonin reuptake inhibitors were compared with active placebos in pain trials but not in depression trials. We identified and analyzed 25 methods publications with substantial comments. The main argument for active placebo was to reduce risk of unblinding; the main argument against was the risk of unintended therapeutic effect.

CONCLUSION

Pharmacological active placebo control interventions are rarely used in randomized clinical trials, but they constitute a methodological tool which merits serious consideration. We suggest that active placebos are used more often in trials of drugs with noticeable side effects, especially in situations where the expected therapeutic effects are modest and the risk of bias due to unblinding is high.

Adjunctive memantine in clozapine-treated refractory schizophrenia: an open-label 1-year extension study

BACKGROUND

In a recent placebo-controlled, double-blind crossover trial (n = 52), significant beneficial effects on memory (d = 0.30) and negative symptoms (d = 0.29) were found after 12 weeks of memantine augmentation in patients with clozapine-refractory schizophrenia. In this open-label 1-year extension study we report the long-term effects and tolerability of memantine add-on therapy to clozapine.

METHOD

Completers of the first trial who experienced beneficial effects during 12 weeks of memantine treatment received memantine for 1 year. Primary endpoints were memory and executive function using the Cambridge Neuropsychological Test Automated Battery, the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impression Severity Scale (CGI-S).

RESULTS

Of 31 randomized controlled trial completers who experienced beneficial effects from memantine, 24 received memantine for 1 year. The small improvement in memory found in the memantine condition in the placebo-controlled trial remained stable in the extension study. Executive function did not improve. After 26 weeks of memantine add-on therapy to clozapine, PANSS negative symptoms (r = 0.53), PANSS positive symptoms (r = 0.50) and PANSS total symptoms (r = 0.54) significantly improved. Even further significant improvement in all these measures was observed between 26 weeks and 52 weeks of memantine, with effect sizes varying from 0.39 to 0.51. CGI-S showed a non-significant moderate improvement at 26 weeks (r = 0.36) and 52 weeks (r = 0.34). Memantine was well tolerated without serious adverse effects.

CONCLUSIONS

In the 1-year extension phase the favourable effect of adjunctive memantine on memory was sustained and we observed further improvement of negative, positive and overall symptoms in patients with clozapine-treated refractory schizophrenia.

Considering benefits and harms of duloxetine for treatment of stress urinary incontinence: a meta-analysis of clinical study reports

BACKGROUND

The European Medicines Agency makes clinical study reports publicly available and publishes reasons for not approving applications for marketing authorization. Duloxetine has been approved in Europe for the treatment of stress urinary incontinence in women. The reported adverse effects of duloxetine include mental health problems and suicidality. We obtained clinical study reports from the European Medicines Agency concerning use of this drug for stress urinary incontinence.

METHODS

We performed a meta-analysis of 4 randomized placebo-controlled trials of duloxetine (involving a total of 1913 patients) submitted to the European Medicines Agency for marketing approval for the indication of stress urinary incontinence in women. We used data from the clinical study reports (totalling 6870 pages and including individual patient data) to assess benefits (including frequency of incontinence and changes in quality-of-life scores, such as Patient Global Impression of Improvement rating) and harms (both general harms, including discontinuation because of adverse events, and harms related to suicidality, violent behaviour and their potential precursors, such as akathisia and activation [stimulating effects such as insomnia, anxiety and agitation]).

RESULTS

Duloxetine was significantly better than placebo in terms of percentage change in weekly incontinence episodes (mean difference -13.56%, 95% confidence interval [CI] -21.59% to -5.53%) and change in Incontinence Quality of Life total score (mean difference 3.24, 95% CI 2.00 to 4.48). However, the effect sizes were small, and a sensitivity analysis (with removal of one trial) showed that the number needed to treat for a Patient Global Impression of Improvement rating of "much better or very much better" was 8 (95% CI 6 to 13). The numbers needed to harm were 7 (95% CI 6 to 8) for discontinuing because of an adverse event and 7 (95% CI 6 to 9) for experiencing an activation event. No suicidality, violence or akathisia events were noted.

INTERPRETATION

Although duloxetine is effective for stress urinary incontinence in women, the rates of associated harm were high when individual patient data were analyzed, and the harms outweighed the benefits.

Placebo Washout is not a Meaningful Part of Antidepressant Drug Trials

Most trials testing the effectiveness of psychotropic drugs begin with a placebo washout phase. Hypothetically this technique rids studies of placebo re-spenders before randomization of subjects to drug and placebo groups. In theory, this lowers the level of response to placebo in the study and magnifies the superiority of the response to medication. An analysis of 10 years of research literature demonstrates that the washout technique does not do what it was designed to do in antidepressant studies. Within placebo or drug groups neither measures of depression nor dropouts were affected by including a preliminary washout in the design. The findings are consistent with the two other studies that have addressed this issue.

Medications as Social Phenomena

This article discusses medications as socially embedded phenomena, using the class of psychoactive medications as a primary example. The analytical perspective is systemic, constructivist, and critical. We suggest that the ‘rational use of drugs’ paradigm fails to appreciate various legitimate rationalities motivating medication usages and is therefore inadequate to understand the place of medications in society. Medications have complex life cycles, with diverse actors, social systems, and institutions determining who uses what medications, how, when and why. Such understanding permits analyzing medications simultaneously as entities and representations. We outline recent changes in usage patterns of psychoactive medications (notably prescriptions to children), in pharmaceutical marketing practices (notably direct-to-consumer advertising), and in the construction of knowledge about drugs (notably the role of the Internet in legitimating consumers’ viewpoints). These changes indicate that medication life cycles evolve and mutate with social and technological change. These life cycles are viewed, then, as systems – part of other social, cultural, and economic systems, themselves in constant change. This perspective provides fertile ground to raise several research questions in order to understand better the nature of medications, their effects, and their place in society.

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 effects of blinding on the outcomes of psychotherapy and pharmacotherapy for adult depression: A meta-analysis

BACKGROUND

Randomized trials with antidepressants are often run under double blind placebo-controlled conditions, whereas those with psychotherapies are mostly unblinded. This can introduce bias in favor of psychotherapy when the treatments are directly compared. In this meta-analysis, we examine this potential source of bias.

METHODS

We searched Pubmed, PsycInfo, Embase and the Cochrane database (1966 to January 2014) by combining terms indicative of psychological treatment and depression, and limited to randomized trials. We included 35 trials (with 3721 patients) in which psychotherapy and pharmacotherapy for adult depression were directly compared with each other. We calculated effect sizes for each study indicating the difference between psychotherapy and pharmacotherapy at post-test. Then, we examined the difference between studies with a placebo condition and those without in moderator analyses.

RESULTS

We did not find a significant difference between the studies with and those without a placebo condition. The studies in which a placebo condition was included indicated no significant difference between psychotherapy and pharmacotherapy (g=-0.07; NNT=25). Studies in which no placebo condition was included (and patients and clinicians in both conditions were not blinded), resulted in a small, but significant difference between psychotherapy and pharmacotherapy in favor of pharmacotherapy (g=-0.13; NNT=14).

CONCLUSIONS

Studies comparing psychotherapy and pharmacotherapy in which both groups of patients (and therapists) are not blinded (no placebo condition is included) result in a very small, but significantly higher effect for pharmacotherapy.

Blinded Outcome Assessment Was Infrequently Used and Poorly Reported in Open Trials

OBJECTIVE

Unblinded outcome assessment can lead to biased estimates of treatment effect in randomised trials. We reviewed published trials to assess how often blinded assessment is used, and whether its use varies according to the type of outcome or assessor.

DESIGN AND SETTING

A review of parallel group, individually randomised phase III trials published in four general medical journals (BMJ, Journal of the American Medical Association, The Lancet, and New England Journal of Medicine) in 2010.

MAIN OUTCOME MEASURES

Whether assessment of the primary outcome was blinded, and whether this differed according to outcome or assessor type.

RESULTS

We identified 258 eligible trials. Of these, 106 (41%) were reported as double-blind, and 152 (59%) as partially or fully open-label (that is, they included some groups who were unblinded, such as patients, those delivering the intervention, or those in charge of medical care). Of the 152 open trials, 125 required outcome assessment. Of these 125 trials, only 26% stated that outcome assessment was blinded; 51% gave no information on whether assessment was blinded or not. Furthermore, 18% of trials did not state who performed the assessment. The choice of outcome type (e.g. instrument measured, rated, or naturally occurring event) did not appear to influence whether blinded assessment was performed (range 24-32% for the most common outcome types). However, the choice of outcome assessor did influence blinding; independent assessors were blinded much more frequently (71%) than participant (5%) or physician (24%) assessors. Despite this, open trials did not use independent assessors any more frequently than double-blind trials (17% vs. 18% respectively).

CONCLUSIONS

Blinding of outcome assessors is infrequently used and poorly reported. Increased use of independent assessors could increase the frequency of blinded assessment.

Systematic review of blinding assessment in randomized controlled trials in schizophrenia and affective disorders 2000-2010

BACKGROUND

Blinding is an integral part of many randomized controlled trials (RCTs). However, both blinding and blinding assessment seem to be rarely documented in trial reports.

METHOD

Systematic review of articles on RCTs in schizophrenia and affective disorders research during 2000-2010.

RESULTS

Among 2,467 publications, 61 (2.5%; 95% confidence interval: 1.9-3.1%) reported assessing participant, rater, or clinician blinding: 5/672 reports on schizophrenia (0.7%; 0.3-1.6%) and 33/1,079 (3.1%; 2.1-4.2%) on affective disorders, without significant trends across the decade. Rarely was blinding assessed at the beginning, in most studies assessment was at the end. Proportion of patients' and raters' correct guesses of study arm averaged 54.4 and 62.0% per study, with slightly more correct guesses in treatment arms than in placebo arms. Three fourths of responders correctly guessed that they received the active agent. Blinding assessment was more frequently reported in papers on psychotherapy and brain stimulation than on drug trials (5.1%, 1.7-11.9%, vs. 8.3%, 4.3-14.4%, vs. 2.1%, 1.5-2.8%). Lack of assessment of blinding was associated with: (a) positive findings, (b) full industrial sponsorship, and (c) diagnosis of schizophrenia. There was a moderate association of treatment success and blinding status of both trial participants (r = 0.51, p = 0.002) and raters (r = 0.55, p = 0.067). Many RCT reports did not meet CONSORT standards regarding documentation of persons blinded (60%) or of efforts to match interventions (50%).

CONCLUSIONS

Recent treatment trials in major psychiatric disorders rarely reported on or evaluated blinding. We recommend routine documentation of blinding strategies in reports.

Varenicline effects on craving, cue reactivity, and smoking reward

RATIONALE

Varenicline is an α4β2 nicotinic acetylcholine receptor partial agonist that has been found to be effective for treating tobacco dependence. However, the subjective and behavioral mediators of its efficacy are not known.

OBJECTIVES

Using multiple sessions of laboratory-based assessment, this double-blind, placebo-controlled experiment was designed to test if varenicline reduced both tonic and cue-provoked tobacco cravings, and if it attenuated perceived reward from smoking.

METHODS

Participants in the present analysis include 100 smokers who were scheduled for three assessment sessions: at baseline, before receiving medication; at mid-run-in, 5-7 days after beginning medication; and after full dosage was reached, 12-15 days. Following overnight abstinence, each session included assessment of tonic craving, reactivity (including craving) to smoking cues, expected value of a cigarette, smoking behavior, and self-reported reward following smoking.

RESULTS

Varenicline, compared to placebo, reduced tonic craving, cue-provoked craving by the final assessment, the expected value of cigarettes, number of puffs and time spent smoking, and self-reported reward (i.e., satisfaction) from smoking.

CONCLUSIONS

Results showing that varenicline reduced tonic craving levels and perceived reward from smoking are consistent with reports from clinical trials, strengthening the evidence in support of these subjective mechanisms of action. This is the first placebo-controlled study to demonstrate that varenicline reduced cue-provoked cravings, thereby offering another potential mediator of its therapeutic effects. Findings may aid in the development of more targeted interventions for tobacco dependence.

Perceived drug assignment and treatment outcome in smokers given nicotine patch therapy

This study assessed the relationship between treatment outcome and perceived drug assignment in smokers (nicotine patch [NP] or placebo) using abstinence and relapse status. Smokers (N = 424) were randomly assigned to receive either NP or placebo as part of a study that examined the effects of combining NP with self-help programs. Beliefs about drug assignment, assessed at the 12-month follow-up, were obtained from 384 participants. Beliefs were related to abstinence at the 2-month, p < .05, and 6-month follow-ups, p < .05, for the NP group, but not the placebo. Beliefs were not related to abstinence at 12 months for either group. Survival analysis assessing relapse revealed that beliefs were related to relapse status, regardless of actual group assignment. Our results suggest that there is a relationship between perceived drug assignment and treatment outcome. Future studies using multiple treatment outcome measures and assessments of beliefs over time are warranted.

Participant expectancies in double-blind randomized placebo-controlled trials: potential limitations to trial validity

BACKGROUND

Randomized controlled trials (RCTs) that use placebo controls to achieve double-blinding intend to establish the efficacy of a treatment over and above expectancy and other forms of bias. Despite this, a growing body of research suggests that participant expectancies can influence the outcomes of these trials.

PURPOSE

and

METHODS

This nonsystematic review examines research assessing the role of participant expectancies in double-blind placebo-controlled RCTs in order to determine if and how they can limit these types of trials.

RESULTS

There appear to be at least three ways in which participant expectancies can limit the validity of double-blind placebo-controlled RCTs. First, when blinding fails researches cannot determine whether any observed improvement in the group receiving active treatment resulted because of the treatment's effect or because of participants' expectancies. Second, participant expectancies could create ceiling effects if there are strong placebo effects in each treatment arm and this may falsely suggest that the active treatment is ineffective without expectancy. Third, the knowledge that a participant will be allocated active treatment or placebo in double-blind placebo-controlled RCTs is likely to lead to weaker treatment responses than would be expected in standard clinical practice, in which patients are unlikely to doubt that they have been given an active treatment.

CONCLUSIONS

Participants' expectancies can undermine the validity of double-blind placebo-controlled RCTs. Researchers conducting these trials should assess participants' beliefs about their treatment allocation and actively investigate if and how these beliefs may have influenced the trial's outcome. Clinical Trials 2010; 7: 246-255. http://ctj.sagepub.com.

Are there placebo effects in the medication treatment of children with attention-deficit hyperactivity disorder?

Placebos have been shown to produce significant positive changes in several health and mental health problems, referred to as placebo effects. Although it is well established that stimulant medication is an empirically supported treatment for children with attention-deficit hyperactivity disorder (ADHD), little is known about the role of placebos in the medication treatment of children with ADHD. This article reviews existing studies that evaluate whether placebos produce significant changes in children with ADHD. Published literature and the author's own empirical work were used to evaluate whether placebo effects are present in the medication treatment of children with ADHD. There is little evidence that placebos produce significant changes in the behavior or cognition of elementary school-age children with ADHD. However, there may be significant placebo effects in adults who evaluate children with ADHD. Evidence suggests that parents and teachers tend to evaluate children with ADHD more positively when they believe the child has been administered stimulant medication and they tend to attribute positive changes to medication even when medication has not actually been administered. Several viable mechanisms for these placebo effects are suggested.

Study blinding and correlations between perceived group assignment and outcome in a cocaine pharmacotherapy trial

While much research has suggested that the integrity of the blind is compromised in psychotropic drug trials, little research has been conducted on blinding in substance abuse trials. The current study examines the integrity of the blind in an outpatient pharmacotherapy trial investigating the effectiveness of amantadine and propranolol in treating cocaine addiction. Results suggest that neither nurses (N = 174, kappa = 0.08, p = 0.22) nor participants (N = 163, kappa = 0.09, p = 0.26) could accurately predict treatment assignment. Furthermore, nurses' perceptions of treatment assignment were significantly related to trial completion, medication compliance, and cocaine use--results that may have training implications for medical personnel.

The antidepressant debate and the balanced placebo trial design: an ethical analysis

There is ongoing debate about whether randomized, placebo-controlled trials under a double-blind have reliably established the pharmacological efficacy of antidepressants. Numerous meta-analyses of antidepressant efficacy trials, e.g., Kirsch et al. [Kirsch, I., Moore, T. J., Scoboria, A., & Nicholls, S. (2002). The emperor's new drugs: An analysis of antidepressant medication data submitted to the U.S. food and drug administration. Prevention and Treatment, 5, Article 23. (Retrieved July 19, 2007 from http://journals.apa.org/prevention/volume5)], have shown a modest drug-placebo difference but methodological problems with standard trial design preclude a definitive conclusion that this difference results from specific biological effects of antidepressants or the nonspecific factors that have not been adequately excluded. Standard trial design assumes the additivity thesis of pharmacological efficacy, being the assumption that the specific or "true" magnitude of the pharmacological effect is limited to the difference between the drug and placebo responses in a standard trial. If the drug effects are as small as these meta-analyses suggest, then their clinical effectiveness is questionable. If the drug effects are actually larger but masked by placebo effects, then the additivity thesis is not valid and we risk false negative results with standard trial design. Kirsch et al. propose an alternative, four arm balanced placebo trial design (BPTD) that can accurately test the additivity thesis. The BPTD uses antidepressants, active placebos and the intentional deception of research subjects. My focal question is whether the BPTD is ethically defensible. I will explore two objections that can be raised against it: 1) lying to BPTD research subjects violates their autonomy and exploits their illness and 2) the BPTD may not enable us to test the additivity thesis with accuracy, i.e., it may contribute to the masking of drug effects that it aims to avoid. I argue that these objections support the conclusion that the BPTD is ethically indefensible.

Relapse following combined treatment discontinuation in a placebo-controlled trial for panic disorder

A recent double-blind, placebo-controlled trial (Barlow et al., 2000 JAMA. 283:2529-2536) examined separate and synergistic effects of psychological and pharmacological treatments for panic disorder. One finding warranting further investigation involved relatively high relapse rates of participants who received cognitive-behavioral therapy (CBT) + imipramine when compared with those receiving CBT + placebo. In this article, we investigate why CBT was less effective in protecting against relapse for individuals in the active drug condition. We hypothesized that participants correctly deduced treatment assignments and, for those taking imipramine, this was associated with the belief that they were no longer taking active drug after discontinuation, accounting for increased relapse rates. Contrary to hypothesis, there were no group differences in frequencies of guessing drug or placebo, nor were specific beliefs about taking drug or placebo differentially associated with relapse. Other possible reasons for differential relapse rates and treatment implications are discussed.

The accuracy of psychiatric medication advertisements in medical journals

Psychiatric medications are frequently advertised in medical journals, yet no study has addressed the veracity of claims made in these advertisements. The present study examined the accuracy of 69 medical journal advertisements for psychiatric medications and the availability of sources cited in these advertisements. Just over half of claims made in advertisements (50.2%) provided no attainable source that could be used to check the veracity of the claim. When sources were attained, they supported the cited claims 65% of the time (95% CI: 61.0-69.1). Claims regarding the efficacy of medications were only supported by obtained cited sources on 53.2% of occasions (95% CI: 46.2-60.2). Attempts to obtain cited data on file from sponsoring drug companies were rarely successful. Given the relatively poor empirical substantiation of claims made in medical journal psychiatric drug advertisements and that most claims provided no attainable sources, increased regulation of such advertising is warranted.

Clinical attrition due to biased preclinical assessments of potential efficacy

Unless it is carefully controlled, bias often distorts the results of clinical trials, usually exaggerating the magnitude of true efficacy. For that reason, procedures to limit bias have been mandated by the FDA when assessing efficacy in clinical trials. The present review shows that the effects of bias in preclinical studies are at least as large as in clinical trials, and since bias is not usually controlled in preclinical proof of concept studies, compounds that actually have little or no therapeutic potential may often be advanced into clinical trials. This possibility is supported by the fact that lack of efficacy is the single biggest reason why compounds fail in the clinic. The shift to target-based discovery during the last 10-15 years may have further increased the effects of bias on preclinical assessments of potential efficacy, and contributed to the continuing decline in clinical success rates. Procedures are available to control for bias during preclinical assessments of potential efficacy, and their use could dramatically increase clinical success rates and substantially reduce the costs of drug discovery and development.

Considering the case for an antidepressant drug trial involving temporary deception: a qualitative enquiry of potential participants

Background

Systematic reviews of randomised placebo controlled trials of antidepressant medication show small and decreasing differences between pharmacological and placebo arms. In part this finding may relate to methodological problems with conventional trial designs, including their assumption of additivity between drug and placebo trial arms. Balanced placebo designs, which include elements of deception, may address the additivity question, but pose substantial ethical and pragmatic problems. This study aimed to ascertain views of potential study participants of the ethics and pragmatics of various balanced placebo designs, in order to inform the design of future antidepressant drug trials.

Methods

A qualitative approach was employed to explore the perspectives of general practitioners, psychiatrists, and patients with experience of depression. The doctors were chosen via purposive sampling, while patients were recruited through participating general practitioners. Three focus groups and 12 in-depth interviews were conducted. A vignette-based topic guide invited views on three deceptive strategies: post hoc, authorised and minimised deception. The focus groups and interviews were tape-recorded and transcribed. Transcripts were analysed thematically using Framework.

Results

Deception in non-research situations was typically perceived as acceptable within specific parameters. All participants could see the potential utility of introducing deception into trial designs, however views on the acceptability of deception within antidepressant drug trials varied substantially. Authorized deception was the most commonly accepted strategy, though some thought this would reduce the effectiveness of the design because participants would correctly guess the deceptive element. The major issues that affected views about the acceptability of deception studies were the welfare and capacity of patients, practicalities of trial design, and the question of trust.

Conclusion

There is a trade-off between pragmatic and ethical responses to the question of whether, and under what circumstances, elements of deception could be introduced into antidepressant drug trials. Ensuring adequate ethical safeguards within balanced placebo designs is likely to diminish their ability to address the crucial issue of additivity. The balanced placebo designs considered in this study are unlikely to be feasible in future trials of antidepressant medication. However there remains an urgent need to improve the quality of antidepressant drug trials.

A comparative meta-analysis of Clinical Global Impressions change in antidepressant trials

Two scales of the Clinical Global Impressions (CGI) Scale are frequently used in antidepressant trials. No research has systematically addressed how CGI change compares to change on established measures such as the Hamilton Depression Rating Scale (HAM-D), Montgomery-Asberg Depression Rating Scale, or Beck Depression Inventory. The current meta-analysis examined 75 antidepressant trials in which the CGI was used along with at least one other popular depression measure. The CGI-Severity scale was significantly more conservative than the HAM-D in rating change in double-blind trials, but not in open trials. The Beck Depression Inventory was significantly more conservative than the CGI-Severity. The CGI-Improvement scale was significantly more liberal than the HAM-D or Montgomery-Asberg Depression Rating Scale. Rater bias or scale content may explain differences between measures. Given the often substantial differences between instruments, researchers should use a variety of measures rather than relying on any single tool in assessing treatment response.

Blindness and bias in a trial of antidepressant medication for chronic tension-type headache

This study aimed to examine penetration of the blind in a randomized, placebo-controlled trial. Neurologists' ratings of improvement and medication side-effects, participants' ratings of improvement and daily diary recordings of headaches were assessed along with participants' and neurologists' guesses about treatment group placement in participants who completed at least 3 months of treatment (N = 169). Despite blinding, treating neurologists successfully identified the medication condition for 82% of participants receiving medication only; trial participants accurately identified their medication condition when receiving active medication (77% of participants), but not when receiving placebo. Concurrent stress-management therapy reduced, but did not eliminate penetration of the blind. Irrespective of drug condition, when participants were improved they were judged to be on active medication and when unimproved they were judged to be on placebo. However, neurologists' ratings of improvement, participants' reports of improvement and daily headache recordings yielded equivalent outcomes. Penetration of the blind needs to be assessed, not assumed in clinical trials in headache. However, penetration of the blind did not produce a prodrug bias as has been asserted by critics. Better methods of assessing and quantifying blindness are needed.

Do antidepressants cure or create abnormal brain states?

Moncrieff and Cohen argue that psychotropic drugs create abnormal states that may co-incidentally relieve symptoms of mental illness.

Is acupuncture analgesia an expectancy effect? Preliminary evidence based on participants' perceived assignments in two placebo-controlled trials

This purpose of this article is to contrast the analgesic efficacy of acupuncture following dental surgery with the analgesic effects based on the expectation of benefit in two independently conducted placebo-controlled trials evaluating acupuncture as an adjunctive therapy for dental surgery. Both trials used pain following dental surgery as the outcome variable, and both included a blinding check to ascertain patients' beliefs regarding which treatment they were receiving. Although no statistically significant analgesic effect was observed between the acupuncture and placebo groups, participants in both experiments who believed they received real acupuncture reported significantly less pain than patients who believed that they received a placebo. Patients' beliefs regarding the receipt of acupuncture bore a stronger relationship to pain than any specific action possessed by acupuncture. These results also support the importance of both employing credible controls for the placebo effect in clinical trials and evaluating the credibility of those controls.

Clotiapine for acute psychotic illnesses

BACKGROUND

Acute psychotic illnesses, especially when associated with agitated or violent behaviour, require urgent pharmacological tranquillisation or sedation. Clotiapine, a dibenzothiazepine neuroleptic, is being used for this purpose in several countries.

OBJECTIVES

To estimate the effects of clotiapine when compared to other 'standard' or 'non-standard' treatments for acute psychotic illnesses in controlling disturbed behaviour and reducing psychotic symptoms.

SEARCH STRATEGY

We updated previous searches by searching the Cochrane Schizophrenia Group Register (April 2004)

SELECTION CRITERIA

The review included randomised clinical trials comparing clotiapine with any other treatment for people with acute psychotic illnesses.

DATA COLLECTION AND ANALYSIS

Relevant studies were selected for inclusion, their quality was assessed and data extracted. Data were excluded where more than 50% of participants in any group were lost to follow up. For binary outcomes we calculated a standard estimation of the risk ratio (RR) and its 95% confidence interval (CI). For continuous outcomes, endpoint data were preferred to change data. Non-skewed data from valid scales were summated using a weighted mean difference (WMD).

MAIN RESULTS

We identified five relevant trials. None compared clotiapine with placebo, but control drugs were either antipsychotics (chlorpromazine, perphenazine, trifluoperazine and zuclopenthixol acetate) or benzodiazepines (lorazepam). Versus the antipsychotics, the results for 'no important global improvement' did not suggest clotiapine to be superior, or inferior, to chlorpromazine, perphenazine, or trifluoperazine (n = 83, 3 RCTs, RR 0.82 CI 0.22 to 3.05, I-squared 58%). Use of clotiapine when compared with chlorpromazine did change the proportion of people ready for hospital discharge by the end of the study (n = 49, 1 RCT, RR 1.04 95%CI 0.96 to 2.12). Overall, attrition rates were low. No significant difference was found for those allocated to clotiapine compared with people randomised to other antipsychotics (n = 121, RR 2.26 95%CI 0.40 to 13). Weak data suggests that clotiapine may result in less need for antiparkinsonian treatment compared with zuclopenthixol acetate (n = 38, RR 0.43 95%CI 0.02 to 0.98). Compared with lorazepam, clotiapine, when used to control aggressive/violent outbursts for people already treated with haloperidol, did not significantly improve mental state (WMD -3.36 95%CI -8.09 to 1.37). We could not pool much data due to skew or inadequate presentation of results. Economic outcomes and satisfaction with care were not addressed.

REVIEWERS' CONCLUSIONS

We found no evidence to support the use of clotiapine in preference to other 'standard' or 'non-standard' treatments for management of people with acute psychotic illness. All trials in this review have important methodological problems. We do not wish to discourage clinicians from using clotiapine in the psychiatric emergency, but well-designed, conducted and reported trials are needed to properly determine the efficacy of this drug.

The blind spot in the nicotine replacement therapy literature: assessment of the double-blind in clinical trials

While clinical trials of medications often use a double-blind procedure, the integrity of the blind and its relationship to treatment outcome is seldom examined. In this review, 73 double-blind, placebo-controlled clinical trials of the nicotine replacement therapies (NRTs) in smoking cessation were identified. Seventeen articles were found that assessed blindness integrity, demonstrating major variations in the assessment, analysis, and reporting of blindness integrity. Although 12 studies found that subjects accurately judged treatment assignment at a rate significantly above chance, the available literature does not permit definitive conclusions about blindness integrity. Recommendations for the assessment, analysis, and reporting of blindness integrity are made.

Independent evaluator knowledge of treatment in a multicenter comparative treatment study of panic disorder

The purpose of this study was to examine independent evaluators' (IEs) blindness to treatment condition during a Multicenter Comparative Treatment Study of Panic Disorder. IEs were 15 doctoral- and masters-level clinicians in psychology, social work, and medicine. They conducted three post-treatment assessments with each patient. Immediately after each assessment interview, IEs completed a form indicating which of the five possible treatments they believed the patient had received and any specific information that provided IEs with information about a patient's treatment condition. These forms were completed for 170 patients. Analyses were conducted to determine the accuracy of guesses about treatment condition by IEs during post-treatment assessments, the relationship between accuracy of IE guessing and actual treatment assignment, the relationship between accurate guessing and outcome ratings, and contributors to the breaking of the blind. A significant relationship was found between IE guesses and actual treatment at all three assessment points, across individual IEs, treatment sites, and IE professional affiliations. IEs were no more accurate in their guessing about patients taking medication than those receiving behavior therapy. Patients and project staff inadvertently provided information to IEs that enhanced the rates of accurate guessing. Implications of these findings on interpretation of the treatment study are discussed, and recommendations are made for improving blindness procedures.

St John's wort, conventional medication, and placebo: an egregious double standard

The efficacy of antidepressant medication is generally thought to be well established, whereas that of hypericum (St John's wort) is considered doubtful. The data fail to support these discrepant conclusions. Instead they show that hypericum and conventional antidepressants are equally effective (or ineffective). This suggests that different standards are being used to evaluate the two types of treatment.

The role of information technology in evidenced-based practice

Clinical Computing is a natural tool for evidence-based practice. Automated self-report produces accurate clinical assessments both in research and clinical settings, thus assuring that patients in each satisfy the same symptom criteria. The Electronic Medical Record (EMR) eventually will form a real-time Information bridge between research and clinical settings. Despite substantial literature demonstrating the efficacy of clinical computing in psychiatric care and research, however, psychiatrists have been slow to adopt computers, and research has dwindled. The steady emergence of system-wide EMRs, will spark a resurgence.

Penetrating the blind in a study of an SSRI

We assessed blind integrity in a double-blinded study comparing paroxetine 20 mg with inert placebo in 20 volunteer subjects who were attempting to stop using methamphetamines. At the end of the study, the blinded clinicians reviewed subject charts and attempted to identify the assigned conditions for the 13 subjects who completed two or more weeks of the study. The three subjects who completed the entire study also attempted to identify their conditions on a questionnaire. We conclude that the blind may unwittingly be broken when the treatments under study are placebo and the selective serotonin reuptake inhibitor (SSRI) paroxetine. The integrity of the blind should be tested in all double-blind SSRI studies.

A systematic review of the quality of homeopathic clinical trials

BACKGROUND

While a number of reviews of homeopathic clinical trials have been done, all have used methods dependent on allopathic diagnostic classifications foreign to homeopathic practice. In addition, no review has used established and validated quality criteria allowing direct comparison of the allopathic and homeopathic literature.

METHODS

In a systematic review, we compared the quality of clinical-trial research in homeopathy to a sample of research on conventional therapies using a validated and system-neutral approach. All clinical trials on homeopathic treatments with parallel treatment groups published between 1945-1995 in English were selected. All were evaluated with an established set of 33 validity criteria previously validated on a broad range of health interventions across differing medical systems. Criteria covered statistical conclusion, internal, construct and external validity. Reliability of criteria application is greater than 0.95.

RESULTS

59 studies met the inclusion criteria. Of these, 79% were from peer-reviewed journals, 29% used a placebo control, 51% used random assignment, and 86% failed to consider potentially confounding variables. The main validity problems were in measurement where 96% did not report the proportion of subjects screened, and 64% did not report attrition rate. 17% of subjects dropped out in studies where this was reported. There was practically no replication of or overlap in the conditions studied and most studies were relatively small and done at a single-site. Compared to research on conventional therapies the overall quality of studies in homeopathy was worse and only slightly improved in more recent years.

CONCLUSIONS

Clinical homeopathic research is clearly in its infancy with most studies using poor sampling and measurement techniques, few subjects, single sites and no replication. Many of these problems are correctable even within a "holistic" paradigm given sufficient research expertise, support and methods.