A recent study published in JAMA Psychiatry by researchers from the University of California, San Francisco, and the San Francisco Veterans Administration Medical Center, explores how altering informed consent processes could mitigate a significant issue in psychedelic drug trials: the high accuracy with which participants can identify whether they received the active drug or a placebo. This phenomenon, known as "functional unmasking," can skew trial outcomes through expectancy effects and placebo responses, potentially inflating the perceived efficacy of the treatment.
Key Findings:
- Between 94% and 100% of participants in psychedelic trials correctly identified when they received the active treatment versus a placebo.
- Expectancy effects, where participants' beliefs about the treatment influence their outcomes, were particularly problematic.
- Modified informed consent strategies included obscuring information about study arms and treatment chances, withholding specific details about drugs and dosages, and masking information about placebo features or comparator drugs.
Examples of Modified Consent:
- A 2006 study informed participants they could receive one of 11 different interventions, though only two—psilocybin and methylphenidate—were actually possible.
- A 2018 study obscured details about methylenedioxymethamphetamine dosages and the identity of the comparator drug.
Ethical Considerations and Recommendations:
- The study emphasizes the importance of ethical compliance, including participant debriefing and transparency about risks.
- Proposed guardrails include mandatory debriefing, participatory research, participant-authorized modifications, and ensuring access to active treatment through open-label extension arms.
- The need for standardized methods to measure expectancy effects and masking success in future trials is highlighted to enhance the rigor and interpretability of psychedelic research.
This research is timely, as the U.S. Food and Drug Administration has granted breakthrough therapy designations to at least five psychedelic treatments, signaling growing interest in their therapeutic potential. The study was supported by the Veterans Administration Mental Illness Research, Education, and Clinical Center, and the NIH National Institute on Aging.
