Summary The difference between ‘placebo group’ and ‘placebo control’: a case study in psychedelic microdosing | Scientific Reports www.nature.com
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The study discusses the distinction between "placebo group" and "placebo control" in psychedelic microdosing, proposes a statistical tool for trial outcome estimation, emphasizes the significance of blinding integrity, and suggests the need for additional trials to support placebo-controlled studies.
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Slide Presentation (10 slides)
Key Points
- Blinding integrity is crucial in controlling for expectancy effects in clinical trials.
- "Activated expectancy bias" (AEB) occurs when weak blinding and positive treatment expectancy lead to an uneven distribution of expectancy effects.
- Microdosing in psychedelic trials can be understood as an active placebo, where perceivable effects are present but do not have genuine medical benefits.
- The Correct Guess Rate Curve (CGRC) is a statistical tool proposed to estimate the outcome of a perfectly blinded trial based on data from an imperfectly blinded trial.
- The observed placebo-microdose differences in a self-blinding microdose trial were susceptible to AEB and may be false positive findings.
- A new blinding integrity assessment tool compatible with the CGRC is recommended for adoption.
- The traditional analysis of the self-blinding microdose trial initially showed small but significant placebo-microdose differences, which were reduced after CGRC adjustment.
- The study emphasizes the need for researchers to carefully assess the source of unblinding and consider the potential for collider bias.
Summaries
40 word summary
A Scientific Reports study examines the difference between "placebo group" and "placebo control" in psychedelic microdosing. They propose a statistical tool to estimate trial outcomes and highlight the importance of blinding integrity. More trials are needed to support placebo-controlled trials.
104 word summary
A study in Scientific Reports explores the difference between a "placebo group" and a "placebo control" in psychedelic microdosing. The researchers introduce the concept of "activated expectancy bias" and propose a statistical tool called the Correct Guess Rate Curve (CGRC) to estimate trial outcomes. They re-analyze data from a microdose trial and suggest that observed differences between groups may be false positives due to expectancy effects. The study emphasizes the importance of distinguishing between different trial designs and introduces a tool for assessing blinding integrity. More trials are needed to collect data on blinding integrity and placebo-controlled trials should be supported by empirical data.
170 word summary
A study published in Scientific Reports examines the distinction between a "placebo group" and a "placebo control" in psychedelic microdosing. The researchers introduce the concept of "activated expectancy bias" (AEB), which occurs when weak blinding and positive treatment expectancy result in an uneven distribution of expectancy effects. They propose a statistical tool called the Correct Guess Rate Curve (CGRC) to estimate the outcome of a perfectly blinded trial using data from an imperfectly blinded trial. The researchers re-analyze data from a self-blinding microdose trial and suggest that the observed differences between the placebo and microdose groups may be false positives due to AEB. They emphasize the importance of distinguishing between trials with a placebo-control group and truly placebo-controlled trials to control for expectancy effects. The study also introduces a new tool for assessing blinding integrity and recommends its adoption. The researchers highlight the need for more trials to collect data on blinding integrity and stress that placebo-controlled trials should only be considered the gold standard if supported by empirical data.
457 word summary
A study published in Scientific Reports examines the distinction between a "placebo group" and a "placebo control" in the realm of psychedelic microdosing. The researchers investigate the concept of blinding in clinical trials and its effects on expectancy effects. They introduce the concept of "activated expectancy bias" (AEB), which arises when weak blinding and positive treatment expectancy result in an uneven distribution of expectancy effects. To estimate the outcome of a perfectly blinded trial using data from an imperfectly blinded trial, the researchers propose a statistical tool called the Correct Guess Rate Curve (CGRC).
To illustrate the impact of AEB and the usefulness of the CGRC, the researchers re-analyze data from a self-blinding microdose trial on psychedelic microdosing. The findings suggest that the observed differences between the placebo and microdose groups in the trial were vulnerable to AEB and could potentially be false positive results. The study argues that microdosing can be seen as an active placebo, where noticeable effects are present but lack genuine medical benefits. Distinguishing between trials with a placebo-control group and truly placebo-controlled trials is crucial in controlling for expectancy effects.
The study also introduces a new tool for assessing blinding integrity that is compatible with the CGRC and recommends its adoption. The researchers emphasize the need for more trials to collect data on blinding integrity and propose a brief questionnaire to identify sources of unblinding. They assert that placebo-controlled trials should only be considered the gold standard if blinding integrity is supported by empirical data.
In the analysis of the self-blinding microdose trial, the traditional analysis initially revealed small but significant differences between the placebo and microdose groups in emotional state, depression, mood, energy, and creativity. However, after applying the CGRC adjustment, only the energy visual analogue scale (VAS) remained significant, albeit with a reduced effect size. The researchers suggest that microdosing may enhance self-perceived energy beyond expectancy effects, but caution that the observed benefits may be influenced by AEB.
The study acknowledges limitations, such as relying on binary treatment guess data and assuming a linear addition of treatment effects in the AEB model. The CGRC adjustment method is also noted to have limitations, including potential confounding variables and dependent observations in the resampling process. The researchers stress the importance of carefully assessing the source of unblinding and considering the potential for collider bias.
Overall, the study underscores the significance of effective blinding in clinical trials and the potential impact of AEB on trial outcomes. It offers insights into the challenges of placebo-controlled trials in the context of psychedelic microdosing and proposes a statistical tool to address these challenges. The study calls for further research and the adoption of blinding integrity assessment tools to enhance the rigor and reliability of clinical trials.
465 word summary
A new study published in Scientific Reports explores the difference between a "placebo group" and a "placebo control" in the context of psychedelic microdosing. The study focuses on the concept of blinding in clinical trials and how it can impact the distribution of expectancy effects. The researchers introduce the concept of "activated expectancy bias" (AEB), which occurs when weak blinding and positive treatment expectancy lead to an uneven distribution of expectancy effects. The study proposes a statistical tool called the Correct Guess Rate Curve (CGRC) to estimate the outcome of a perfectly blinded trial based on data from an imperfectly blinded trial.
To demonstrate the impact of AEB and the utility of the CGRC, the researchers re-analyzed data from a self-blinding microdose trial on psychedelic microdosing. The results suggest that the observed placebo-microdose differences in the trial were susceptible to AEB and may be false positive findings. The study argues that microdosing can be understood as an active placebo, where perceivable effects are present but do not have genuine medical benefits. The researchers highlight the importance of distinguishing between trials with a placebo-control group and genuinely placebo-controlled trials, as blinding integrity is crucial in controlling for expectancy effects.
The study also presents a new blinding integrity assessment tool that is compatible with the CGRC and recommends its adoption. The researchers emphasize the need for more trials to capture blinding integrity data and propose a brief questionnaire to assess the source of unblinding. They argue that placebo-controlled trials should only be considered gold standard if blinding integrity is demonstrated with empirical data.
In the analysis of the self-blinding microdose trial, the traditional analysis initially showed small but significant placebo-microdose differences in emotional state, depression, mood, energy, and creativity. However, after CGRC adjustment, only the energy visual analogue scale (VAS) remained significant, although with a reduced effect size. The researchers suggest that microdosing may increase self-perceived energy beyond expectancy effects, but caution that the observed benefits may be driven by AEB.
The study acknowledges several limitations, including the reliance on binary treatment guess data and the assumption of linear addition of treatment effects in the AEB model. The CGRC adjustment method is also noted to have limitations, such as potential confounding variables and dependent observations in the resampling process. The researchers emphasize the need for researchers to carefully assess the source of unblinding and consider the potential for collider bias.
Overall, the study highlights the importance of effective blinding in clinical trials and the potential impact of AEB on trial outcomes. It provides insights into the challenges of placebo-controlled trials in the context of psychedelic microdosing and proposes a statistical tool to address these challenges. The study calls for further research and adoption of blinding integrity assessment tools to improve the rigor and reliability of clinical trials.