Lack of tolerance to the effect of two tetrahydrocannabinols on aggressiveness
- Cite this article as:
- ten Ham, M. & van Noordwijk, J. Psychopharmacologia (1973) 29: 171. doi:10.1007/BF00422649
Experimental animals develop tolerance to the effect of tetrahydrocannabinol (THC) in most experimental situations. In this study the effect of chronic treatment with δ8- and δ9-THC on the aggressiveness of isolated mice and Chinese hamsters was investigated. Both compounds still suppressed the aggressiveness after thirty daily administrations. After the period of treatment the aggressiveness of the treated animals was equal to that of control animals. It is therefore concluded that mice and Chinese hamsters do not develop tolerance for the aggression-suppressing effect of THC. The tolerance found by other investigators to other effects can be explained by assuming activity of THC-metabolites in causing these effects and activity of THC itself in causing the inhibition of aggression.