Frederick Barrett

Frederick S. Barrett is a psychologist and neuroscientist broadly affiliated with the field of clinical psychedelic research, best known for collaborative work with major centres in the United States on psilocybin and other serotonergic compounds. He has played a prominent role in trials and human laboratory studies exploring therapeutic applications of psychedelics, as well as mechanistic investigations using neuroimaging and receptor-occupancy approaches. Barrett is a frequent co-author with investigators such as Roland R. Griffiths and Matthew W. Johnson and has contributed to both clinical trial reports and methodological papers that seek to strengthen rigour in psychedelic research.

Barrett's substantive contributions include the development and validation of psychometric instruments used to quantify acute subjective phenomena (for example, measures of challenging experiences and psychological insight), analyses of safety signals (including work examining coadministration risks such as seizures associated with lithium), and experimental studies of music-evoked brain activity under LSD and psilocybin. He has also contributed to naturalistic cohort studies and to comparative cognition research examining hallucinogen users versus controls. Across these domains he has emphasised careful measurement, reproducible methods, and the integration of subjective-report instruments with neurobiological data to advance understanding of therapeutic mechanisms and safety considerations in psychedelic-assisted interventions.