Introduction Clinical and observational studies of the effects of lysergic acid diethylamide (LSD25) have aroused much interest in recent years because of the unusual nature of the alterations in functioning that have been observed. Many have seen a possible relationship between these alterations and the disturbances seen in schizophrenic syndromes or, more generally, under conditions of altered levels of consciousness, such as sleep deprivation, hypnosis, and sensory isolation, and have been stimulated to explore the effects of the drug in great detail.4,7,9,10,16-19The scope of possible change is wide and includes a variety of disturbances in ego functions, alterations in drive manifestations, and other psychopathology. These alterations have been conceptualized in a variety of ways. Savage,19for example, described changes in autonomic functioning, motor functioning, mood, conation, cognition, and sensorium. Disturbances in thought and speech, affect, perception, behavior and