A. Hofmann first noted that extraordinary psychic symptoms were induced by LSD-25 (D-lysergic acid diethylamide). Subsequently, W. A. Stoll25 and G. Condrau5 discussed these symptoms from a phenomenological point of view. Since then numerous studies have been made including those by J. Delay,7 M. Rinkel,21 W. Frederking,8,9 S. Salvatore,22 and H. Isbell and associates.12 In spite of these investigations, there is, however, no general agreement concerning the interpretation of the so-called LSD-psychosis. Certain of these presumed or inferred that a certain chemical substance might indeed cause schizophrenia. It is clear, however, that all of the LSD symptoms cannot have a necessary relationship to schizophrenia because, as confirmed by many authors, these vary according to the subjects and dosage, among other factors. The effect of LSD on the human subject is too variable to permit the identification of