Behavioral effects produced by long-term administration of a neuroleptic drug (flupenthixol) upon social interaction in a group of eight rats.

The behavioral effects produced by chronic treatment with alpha-flupenthixol decanoate followed by a 3-month pause upon social interaction in a group of eight rats were studied. alpha-Flupenthixol decanoate induced total disruption of two of the group formations studied, i.e., three or more in a group outside a corner and three or more following (running in a row)--the overall behavioral change shows a general depressive effect of the drug and a change in the pattern of social interaction. The shift in balance between the behavioral categories measured appeared as a significant difference in the time spent in the various group formations. Disintegration of group coherence, as shown in the measures of the degree of isolation, appeared only in the alpha-flupenthixol decanoate-treated group. An apomorphine test, which concluded the experiment 3 months after the last alpha-flupenthixol decanoate injection, revealed a significant difference in relation to licking response between the test group and the control group. The apomorphine test reported in this paper showed effects up to 90 days after the last drug treatment.