Use of the classic hallucinogen psilocybin for treatment of existential distress associated with cancer

This chapter reviews the potential of a treatment approach that uses psilocybin, a novel psychoactive drug, to ameliorate the psychospiritual distress and demoralization that often accompany a life-threatening cancer diagnosis. The focus of cutting-edge research beginning in the 1950s, the investigation of classic hallucinogens had a major impact on the evolving field of psychiatry, contributing to early discoveries of basic neurotransmitter systems and to significant developments in clinical psychopharmacology. While published reports of therapeutic breakthroughs with difficult-to-treat and refractory patient populations were initially met with mainstream professional enthusiasm, by the late 1960s and early 1970s the growing association of hallucinogens with widespread indiscriminate use led to the temporary abandonment of this promising psychiatric treatment model. After a hiatus lasting several decades, however, regulatory and scientific support has grown for the resumption of clinical research investigations exploring the safety and efficacy of a treatment model utilizing the classic hallucinogen, psilocybin, in a subject population that had previously demonstrated positive therapeutic response, patients with existential anxiety due to a life-threatening cancer diagnosis.