Social influences on the response to drugs

Summary Ninety male albino rats were assigned to three groups of 30 animals each. Ss in each group were housed individually but were paired for testing. One S in each pair received either saline, amphetamine, or chlorpromazine depending upon the group. Pairs of animals, consisting of one treated and one non-treated rat, were placed in an observation box and a number of categories of behavior observed and recorded. It was found that the behavior of the non-treated rats, in the case of the amphetamine and chlorpromazine groups, was modified. In the amphetamine group the behavior of the non-treated rats essentially mirrored the behavior of the treated animals. In the chlorpromazine group the primary change in the non-treated animals was in the category of active social behavior where they demonstrated significantly more of this type behavior than did the treated rats. There were no significant differences in behavior shown between the treated and non-treated animals in the saline group.This research was supported by research grant MH-08407-01 from the National Institute of Mental Health. The authors wish to express their gratitude to Lesley Diehl and Linda Dekker for their aid in collecting data in this investigation.