Psilocybin, Synesthesia and Informed Consent

Psilocybin, synesthesia and informed consent. What a mashup!

When a person can hear the color “blue,” or taste the word “apple,” can that person legally give consent? What if a client requests a facilitator to give a reassuring touch during an administration session, but later sues the facilitator for unwanted physical contact?

Oregon is in the process of developing regulations for the psilocybin services industry, and one concept still in development is informed consent. Last fall, the Licensing Subcommittee produced a draft of an informed consent form available here. To provide psilocybin services to a client, the client must give the facilitator informed consent. The client will review and sign an informed consent form prior to the administration session, which is when the client consumes psilocybin.

But what if a client changes their mind during the administration session?

What is informed consent?

Informed consent is an agreement with sufficient knowledge of relevant facts, and is often required for legal services, scientific research and medical treatment. For example, a medical patient must agree to undergo surgery before the procedure can begin. After the patient hears all of the information relevant to the surgery (the risks, benefits, and alternatives), the patient can then give informed consent to the healthcare provider.

One problem that occasionally arises is alcohol intoxication. Informed consent is not legally sufficient if a person lacks the capacity to make an informed decision. While intoxication alone does not diminish capacity, if a person is too intoxicated to understand the risks of a surgery, they cannot legally agree to it. Similarly, if a person agrees to participate in a scientific study, but is too intoxicated to understand what the study entails, that data cannot be used in the study.

Alcohol intoxication impairs cognitive functions, which diminishes capacity to make decisions and thus can bar informed consent. But what about a non-ordinary state of consciousness induced by psilocybin?

Psilocybin and consciousness

A facilitator must obtain informed consent prior to the administration session, but things may change after the session begins. What if a client does not consent to physical contact before consuming psilocybin, but suddenly requests a reassuring touch during the administration session? Does a non-ordinary state of consciousness diminish the client’s capacity? Will a facilitator have to determine capacity during the administration session, similar to emergency responders on the scene?

In the brain, psilocybin affects the claustrum, a collection of neurons and glial cells that connects different parts of the brain. This chemical interaction temporarily alters a person’s consciousness, and people commonly experience a heightened sense of connectivity, complex imagery, and sensory alterations. Further, studies show significant doses of psilocybin induce synesthesia.

Synesthesia is a heightened perception of one’s surroundings, involving connected physical sensations, images, and thoughts. A person experiencing synesthesia can hear a Beatles’ song and see a fractal image appear in the visual field or taste warm soup when they hear the word “home.” Various theories are still developing to explain this and other effects of psychedelics.

Alcohol interferes with a person’s balance, memory, speech, and judgment. Intoxication from alcohol and a non-ordinary state of consciousness from psilocybin are clearly two different cognitive states. But will the law treat both states the same for informed consent purposes?


Current research is still analyzing whether psilocybin heightens consciousness entirely, or merely enhances some cognitive activity while dampening others. Nevertheless, informed consent is an increasingly important topic for ethics in psychedelic therapy. In fact, the Multidisciplinary Association for Psychedelic Studies (MAPS) allows for informed consent during a non-ordinary state of consciousness, per their code of ethics.

Psilocybin service businesses could adopt similar policies for informed consent. But until there is more research on the decision-making capabilities of someone who ingests psilocybin, it is unclear whether a court of law would find that person to have legal capacity for consent.