MODULATION OF THE INDUCTION OR EXPRESSION OF PSYCHOSTIMULANT SENSITIZATION BY THE CIRCUMSTANCES SURROUNDING DRUG ADMINISTRATION

The conditions necessary to induce psychomotor sensitization and to pr omote its expression are not well understood. Two examples are reviewe d here of how the circumstances surrounding drug administration (''set and setting'') can powerfully modulate the sensitization produced by psychostimulant drugs, such as amphetamine or cocaine. In the first ex ample it is suggested that repeated exposure to psychostimulant drugs may induce ''neural sensitization'' (i.e., produce relevant adaptation s in the nervous system). The circumstances surrounding drug administr ation may determine, however, whether neural sensitization is expresse d in behavior. In the second example it is suggested that the circumst ances surrounding drug administration may determine whether sensitizat ion is induced at all, or at least the rate and extent of sensitizatio n produced by a given dose of a drug. It is concluded that psychomotor sensitization is not an inevitable consequence of exposure to psychos timulant drugs, but is the result of interactions amongst the pharmaco logical actions of drugs and the circumstances surrounding drug admini stration. (C) 1998 Elsevier Science Ltd. All rights reserved.