Glossary: Psychedelic Medicine

Palinopsia

A visual disturbance in which images persist or recur after the original stimulus has disappeared.

Partera

A traditional midwife who provides prenatal care, childbirth assistance, postpartum support, and women's health care within community-based and culturally grounded traditions.

Partial Agonist

A compound that binds to and activates a receptor but produces a smaller maximal response than a full agonist.

Peyote (Lophophora williamsii)

A small spineless cactus native to northern Mexico and the southwestern United States that contains mescaline. Peyote is considered a sacred medicine by many Indigenous peoples, including members of the Native American Church.

Pharmacogenomics

The study of how genetic variation influences an individual's response to medications. In psychedelic medicine, pharmacogenomics examines genes affecting drug metabolism (e.g., CYP2D6, CYP2C19, CYP3A4), neurotransmitter systems (e.g., HTR2A, SLC6A4), and neuroplasticity to guide safer dosing, predict therapeutic response, and reduce adverse effects.

Pharmacognosy

The scientific study of medicines derived from natural sources, including plants, fungi, marine organisms, and microorganisms.

Phytocannabinoid

A cannabinoid produced naturally by plants, particularly Cannabis species.

Phytochemistry

The scientific study of the chemical constituents of plants and their biological properties.

Pilgrimage

A purposeful journey to a place of spiritual, religious, or personal significance undertaken for healing, devotion, transformation, or reflection.

Power Differential

The imbalance of authority, influence, or vulnerability that exists between clinicians or facilitators and those receiving care.

Precision Psychiatry

An emerging field that integrates clinical assessment with genetics, pharmacogenomics, neuroimaging, biomarkers, and environmental factors to individualize psychiatric diagnosis, treatment selection, and prognosis.

Predictive Processing

A theory proposing that the brain continuously generates predictions about incoming sensory information and updates those predictions based on new experience.

Preparation

The collaborative process of assessing readiness, establishing goals, providing education, building rapport, and addressing medical, psychological, and practical considerations before a psychedelic or other consciousness-altering experience.

Preparation Phase

The structured clinical process preceding a psychedelic session that includes screening, informed consent, therapeutic alliance, intention setting, psychoeducation, safety planning, and development of coping strategies.

Psilocin

The active metabolite of psilocybin that readily crosses the blood-brain barrier and acts primarily as a partial agonist at serotonin 5-HT2A receptors. Psilocin is responsible for the psychoactive effects of psilocybin-containing mushrooms.