Modulation of the subjective and physiological effects of drugs by contexts and expectations--the search for mechanisms: comment on Alessi,Roll, Reilly,and Johanson (2002)

Contexts and expectations can change the subjective and physiological effects of psychotropic drugs. Learning and conditioning processes clearly contribute to some of these effects. It must be considered, however, that even the acute effects of drugs can be significantly altered by the context in which they are administered. The challenge is to determine the mechanisms operating to bring about these changes.