Pills and improvement: a study of placebo response in psychoneurotic outpatients

Effectiveness of physiotherapy interventions on headache intensity, frequency, duration and quality of life of patients with tension-type headache. A systematic review and network meta-analysis

BACKGROUND

This systematic review assesses the effectiveness of physiotherapy on headache parameters and quality of life of patients with tension-type headache using network meta-analysis.

METHODS

A systematic search was conducted in the databases Web of Science, Medline, Cochrane Library and Physiotherapy Evidence Database up to August 2021. Randomised controlled trials investigating the effect of physiotherapy on tension-type headache were included. Risk of bias assessment was performed using the Risk of bias tool 2.0. Results were presented according to the Cochrane handbook and the PRISMA statement.

RESULTS

Twenty reports were eligible and 15 were included in network meta-analysis for pain intensity and frequency. Transcutaneous electrical stimulation combined with physiotherapy was the most effective approach to reduce pain intensity compared to control (mean difference (MD): -4.18, moderate confidence) and usual care (MD: -3.8, moderate confidence) Manual therapy (joint mobilisation) plus exercise was the most effective intervention to reduce headache frequency compared to control (MD: -13.03, low confidence) and usual care (MD: -13.95, moderate confidence).

CONCLUSION

Results suggest a combination of passive physiotherapy techniques with exercise and/or transcutaneous electrical stimulation as the most effective physiotherapy intervention to reduce pain intensity and frequency in the short term. More research is needed to investigate mid-term and long-term effects.Trial registration: This review was prospectively registered in www.aspredicted.org under the registration number #46098 and an updated protocol was registered in the Open Science Framework (OSF) with the registration DOI: https://doi.org/10.17605/OSF.IO/RVUEY.

Does the placebo effect on hot flashes depend on the placebo dose?

PURPOSE

To investigate the presence of a placebo dose-response effect in four randomized, double-blind, placebo-controlled, multi-dose hot flash clinical trials conducted at Mayo Clinic.

METHODS

Hot flash score, frequency, and hot flash-related distress for each placebo dose level were summarized at each time point by mean and standard deviation and changes from baseline were plotted to visualize a possible placebo dose-effect response. Furthermore, a meta-analysis was conducted for each endpoint in the highest and lowest dosage arms across the four trials.

RESULTS

Longitudinal plots of mean hot flash scores, frequencies, and hot flash-related distress scores in patients taking placebo in each study showed a decline in hot flash scores over time without any clinically meaningful differences between the lowest and highest dosage arms in each study. The meta-analysis for each endpoint in the highest and lowest dosage arms across the four trials revealed no clinically important differences either.

CONCLUSION

While the current study cannot rule out the existence of a placebo dose-response effect in multi-dose placebo-controlled trials in patients with hot flashes or other conditions, it suggests, along with the available data in the placebo literature, that, at least in well-conducted multi-dose clinical trials in which the placebo was used as control, such an effect, if it exists at all, should be very small. Therefore, pooling data from different placebo subgroups is unlikely to compromise the validity of comparisons between the combined placebo arms and each treatment arm.

Placebo Effects in Traumatic Brain Injury

In recent years, several randomized controlled trials evaluating pharmaceutical treatments for traumatic brain injury (TBI) have failed to demonstrate efficacy over placebo, with both active and placebo arms improving at comparable rates. These findings could be viewed in opposing ways, suggesting on the one hand failure of the tested outcome, but on the other, representing evidence of robust placebo effects in TBI. In this article, we examine several of the primary psychological processes driving placebo effects (verbal suggestion, cognitive re-framing, interpersonal interactions, conditioning, therapeutic alliance, anxiety reduction) as well as placebo neurobiology (top-down cortical regulation, reward system activation, dopaminergic and serotonergic neurotransmission). We then extrapolate from the literature to explore whether something inherent in TBI makes it particularly responsive to placebos. Viewed as such here, placebos may indeed represent a powerful and effective treatment for a variety of post-TBI complaints.

Cost-Effectiveness Analysis: Discount the Placebo at Your Peril

Introduction: The authors consider alternative mechanisms that might explain placebo responses and their implications for cost-effectiveness modeling. Three alternative placebo mechanisms are examined: a ‘‘regression to the mean’’ effect arising from natural variation and the preferential selection of patients with acutely severe disease into clinical trials, a patient expectancy effect specific to the clinical trial setting (Hawthorne effect), and a patient expectancy effect generalizable to routine clinical practice (true placebo effect). Methods: To estimate cost-effectiveness, the authors needed to generalize from trial data to estimate responses to treatment that they would see in routine clinical practice. They use an example analysis of the cost-effectiveness of adjunct epilepsy treatments to illustrate the potential effects of these different placebo mechanisms on this generalization and subsequent cost-effectiveness estimates and adoption decisions. Results: If an acceptable willingness-to-pay threshold of 30,000 per quality-adjusted life year (QALY) is assumed, then each of the placebo effect scenarios identifies a different treatment alternative as being optimum. Discussion: Estimated cost-effectiveness ratios and associated policy decisions may be sensitive to assumptions regarding the mechanism underlying placebo responses. These assumptions should, if possible, be investigated through analysis of trial or observational data and, in the absence of other evidence, sensitivity analysis.

Placebo effect in the treatment of duodenal ulcer

AIMS

To assess whether frequency of placebo administration is associated with duodenal ulcer healing.

METHODS

A systematic literature review of randomized clinical trials was undertaken. 79 of 80 trials that met the inclusion criteria. The pooled 4 week placebo healing rate of all duodenal ulcer trials that employed a four times a day regimen was compared with the rate obtained from trials with a twice a day regimen.

RESULTS

The pooled 4 week healing rate of the 51 trials with a four times a day regimen was 44. 2% (805 of 1821 patients) compared with 36.2% (545 of 1504 patients) in the 28 trials with a twice a day regimen (difference, 8.0% [equal effects model]; 95% confidence interval, 4.6% to 11.3%). Depending on the statistical analysis, the rate difference ranged from 6.0% (multivariable random effects model) to 8.0% (equal effects model). A number of sensitivity analyses showed comparable differences between the two regimens. Most of these sensitivity analyses were not significant, probably because a number of trials were excluded resulting in a loss of power.

CONCLUSIONS

We found a relation between frequency of placebo administration and healing of duodenal ulcer. We realize that the comparison was based on nonrandomized data. However, we speculate that the difference between regimens was induced by the difference in frequency of placebo administration. A better knowledge of various placebo effects is required in order to make clinically relevant assessments of treatment effects derived from placebo-controlled trials.

A comparison of the electroencephalographic spectral modifications induced by diazepam and by hydroxyzine

A double-blind, randomized controlled trial using an electroencephalograph computerized analysis and cartography was carried out to investigate the spectral modifications induced by diazepam and hydroxyzine. Without monitoring response to stimulation, the spectra found for diazepam and for hydroxyzine were qualitatively very similar, showing increase of the slow waves, reduction of the alpha rhythm and accentuation of the beta 1 rhythms. These traces suggested strongly that both drugs had produced a sedative, anti-anxiety effect. The intensity of the effect produced by 50 mg of hydroxyzine appeared to be less than that produced by 10 mg diazepam. After monitoring response to stimulation, the spectra were modified and the reactivity of the two drugs differed with regard to the slow delta, theta and alpha 1 frequency bands. It was possible to distinguish between the sedative and anti-anxiety effects of both diazepam and hydroxyzine. Even if the two drugs had some similar effects, the mode of action in the central nervous system was certainly different, as can be seen from the characteristics of distribution of the slow waves, their reactivity and, with regard to frequency, the fluctuation of the dominant frequency of rapid rhythms.

Characteristics of panic disorder patients responding to placebo

Forty-one panic disorder patients receiving placebo were investigated in a double-blind comparison of alprazolam, imipramine and placebo in panic disorder. A significantly higher drop-out rate was found in the placebo group than in the active treatment groups, but placebo response was found in 34% of the patients, defined as reduction of panic attacks to zero, and in 23%, defined as a score of greater than or equal to 8 on the Physician Global Improvement Scale (0-10 points). Several predictors of response to placebo were found. The responders had fewer panic attacks than the nonresponders at baseline. They also reported less psychopathology and were less help-seeking than the nonresponders. The implications for psychopathology and possible response to psychotherapy among responders and nonresponders are discussed. It is hypothesized that the responders show more signs of realistic processing of internal and external stimuli and fewer signs of subjective distress than the nonresponders. Responders will therefore probably be more responsive to psychotherapy than nonresponders.

Analgesic effects of branding in treatment of headaches

The effect of branding--that is, the labelling and marketing--of a well-known proprietary analgesic used to treat headaches was studied in a sample of women given a branded or unbranded form with either an inert or an active formulation. The sample was also divided according to whether the subjects were regular users of the brand or users of other brands. The findings showed that branded tablets were overall significantly more effective than unbranded tablets in relieving headaches. Differential effects were observed: the effects of branding were more noticeable one hour after the tablets were taken compared with 30 minutes; in the women given the placebo; and in the users of the brand compared with the users of other brands. It is hypothesised that these effects are due to increased confidence in obtaining relief with a well-known brand, and that branding has an analgesic effect that interacts with the analgesic effects of placebos and active ingredients.