There has been, thus far, virtually no exploration of an empirical basis of the patterning of subjective reactions to lysergic acid diethylamide (LSD-25). Previous studies have been limited to general descriptions of the drug's effects, and the rare attempts to group the various specific effects have been based on a priori clinical concepts1 (reviewed elsewhere). Furthermore, the relationships between a given LSD-25 reaction and the personalities of the individuals who manifest that reaction have been neglected. This report presents data bearing on these unexplored areas.
The present attempt to differentiate empirically major dimensions of the LSD-25 reaction may be contrasted with previous studies which have presented clinical and, to some extent, systematic summaries of the separate aspects of the drug reaction. Only Salvatore and Hyde3 and our own previous report1 were concerned with clusters of reactions, and