The decline in therapeutic research with lysergic acid diethylamide (LSD) in the United States over the course of the 1960s has commonly been attributed to the growing controversy surrounding its recreational use. However, research difficulties played an equal role in LSD psychotherapy's demise, as they frustrated researchers' efforts to clearly establish the efficacy of treatment. Once the Kefauver Harris Drug Amendments of 1962 introduced the requirement that proof of efficacy be established through controlled clinical trials before a drug could be approved to market, the value of clinical research became increasingly dependent on the scientific rigor of the trial's design. LSD psychotherapy's complex method of utilizing drug effects to catalyze a psychological treatment clashed with the controlled trial methodology on both theoretical and practical levels, making proof of efficacy difficult to obtain. Through a close examination of clinical trials performed after 1962, this article explores how the new emphasis on controlled clinical trials frustrated the progress of LSD psychotherapy research by focusing researchers' attention on trial design to the detriment of their therapeutic method. This analysis provides a new perspective on the death of LSD psychotherapy and explores the implications of the Drug Amendments of 1962.
Keywords: Drug Amendments of 1962; LSD; controlled clinical trial; drug regulation; efficacy; psychiatry; psychopharmacology; psychotherapy.