Current Status and Future Trends in Psychedelic (LSD) Research

Since LSD's discovery in 1943, extensive research has documented its powerful effects on brain processes and autonomic functions, including lowered arousal thresholds and heightened sensory sensitivity. These psychopharmacological changes align with clinical findings of pronounced perceptual, affective, and ideational alterations. However, beyond these broad patterns, results have been inconsistent and often contradictory, even in simpler animal species. Methodological problems—especially in human studies—such as organic complexity, measurement shortcomings, individual differences, lack of adequate theoretical models, and non-drug variables like set and setting, have hindered progress. Additionally, a medico-legal-social controversy has obscured empirical questions and inhibited objective investigation.

Study at a glance

Abstract

Since the discovery of d-lysergic acid diethylamide (LSD-25) in 1943, a voluminous literature has accumulated concerning its effects on a variety of animals, including man. Despite the mass of published reports, definitive evidence is generally lacking, particularly with regard to the subjective and behavioral effects both during and subsequent to the LSD induced state. It is well established that this powerful agent produces major alterations in cerebral processes and central autonomic functions. There is also ample evidence indicating a markedly lowered threshold for arousal (Key & Bradley, 1960) and an increased sensitivity to stimuli in all modalities (Klee, 1963). These psychopharmacological effects parallel the findings of clinical and behavioral studies at least on the molar descriptive level. Pronounced perceptual changes have been almost invariably demonstrated with concomitant alterations in affect, ideation, and the relationship between subject and environment (Hoffer, 1965). Beyond these rather global findings, results have been inconsistent and often contradictory, even within species far less complex than man (Cohen, 1964). The well-known methodological problems encountered in research with centrally acting drugs are at least partly responsible for the slow progress thus far (Zubin & Katz, 1964). This has been especially true with human subjects. Systematic study of human reactions to LSD poses unique problems associated with greater organic complexity, shortcomings of currently available measuring devices, the ubiquity of individual differences, lack of an adequate theoretical model, and the influence of non-drug variables such as set and setting. In addition to these experimental obstacles, LSD has until recently been the center of a complicated medico-legal-social controversy (Harman, 1964). This has tended to obscure the relevant empirical questions and inhibit investigations which are both imaginative and reasonably objective.