BEHAVIORAL PROFILE OF TRAZODONE, AN ATYPICAL ANTIDEPRESSANT, IN AGONISTIC ENCOUNTERS BETWEEN MALE-MICE

Although the antiaggressive properties of antidepressant drugs are wel l-known, there is no evidence concerning the possible antiaggressive p rofile of trazodone, an atypical antidepressant which acts as a seroto nin antagonist at low doses and an agonist at higher doses. We assesse d the effects of acute administration of trazodone (0.75-10 mg kg(-1), i.p.) in agonistic interactions between male mice. Individually house d mice were exposed to anosmic 'standard opponents' 30 min after drug administration and the encounters were videotaped and evaluated using an ethologically based analysis. Trazodone exhibited a biphasic ethoph armacological pattern characterised by an increase in aggression at lo w doses (0.75 mg kg(-1)), a specific suppression of aggression at inte rmediate doses (2.5 mg kg(-1)), and a non-selective decrease in offens ive behaviours at higher doses (5 and 10 mg kg(-1)). An interaction be tween trazodone and its metabolite CPP is suggested to explain this be havioural profile.