MAPS has two basic functions. The first is to support research and advance knowledge into the medical, scientific, religious, therapeutic, and recreational uses and abuses of psychedelic substances and techniques. The second is to serve as an educational organization to disseminate information from our research, facilitate discussion and promote the integration of psychedelic usage into our culture in whatever slow, gradual approaches suggest themselves.

Psychedelic, a word coined in the 1950's by Humphrey Osmond meaning "mind-manifesting", refers to more than just LSD. It includes a wide variety of substances and non-drug techniques that have in common the ability to facilitate the bringing forth, the manifesting, of portions of the contents of an individual's mind into more conscious awareness. Psychedelically-assisted experiences are only one small step in the long, slow process of discovery, integration, and growth.

Primarily, MAPS is involved with research into MDMA (Ecstasy) and has opened a Drug Master File for MDMA at the Food and Drug Administration. MAPS assists the efforts of researchers both in the US and abroad who seek to explore the risks and benefits of MDMA-assisted psychotherapy. MAPS attempts to act as a bridge between the psychedelic research community, who have been driven out of their research labs for a generation, and government regulators who must give their permission before legally approved research can begin.

MAPS also explores the consequences of the non-medical use of MDMA, supports the Native American Church in their struggle to continue the religious use of peyote, encourages efforts to renew LSD research, investigates the medical use of marijuana, and explores ways in which psychedelic psychotherapy may prove useful in the treatment of drug abuse.