British-born John Beresford began his psychedelic research interests in 1961, and shortly thereafter he resigned his post as an Assistant Professor of Pediatrics at New York Medical College. In 1963 he founded the Agora Scientific Trust, the world's first research organization devoted to investigating the effects of LSD. In contrast to Leary's invitation to "tune in, turn on, and drop out", Beresford initially wanted to keep LSD as a tool of scientifically trained specialists. However, later in his life he adopted a viewpoint that was opposed to the medicalization of psychedelics.

He spent the next several decades working in psychiatry until 1991, when he resigned and founded the Committee on Unjust Sentencing, an advocacy group focused on the plight of people imprisoned on psychedelics-related charges. Beresford testified in front of the U.S. Sentencing Commission and spoke out on his passion in many forums. He collaborated with Karen Hoffman and Becky Stewart to create and publish The Tallahassee Project--a collection of testimonials and photographs of women incarcerated at the federal prison in Tallahassee, Florida. In his later years he lived in Canada and continued to correspond with psychedelic prisoners. Beresford acted as secretary of the Albert Hofmann Foundation, and archived a large collection of art and printed materials related to LSD. Though it never manifested, his dream was to create a museum open to the public, so that the historical evidence of the important impact of LSD would always be available and could never be forgotten or buried. In 1996, Beresford teamed up with Werner Pieper in Germany to host the First International Drug War Prisoners Conference, and a second similar conference was held in Canada in 1999. In 2006 at the international symposium on the occasion of the 100th birthday of Albert Hofmann in Basel, Switzerland, Beresford presented the talk "Psychedelic Agents and the Structure of Consciousness: Stages in a Session Using LSD and DMT".

Beresford was known for his outspokenness and persistence on many topics, and is fondly remembered for his tireless devotion to the causes he championed.