THE EFFECTS OF COCAINE AND NANDROLONE COADMINISTRATION ON AGGRESSION IN MALE-RATS

1. Cocaine and anabolic-androgenic steroids are among the more commonl y abused substances in selected populations. These agents, when used a lone or in combination, have been reported to cause aggressive tendenc ies in both laboratory-based animal models and in human clinical situa tions. This project, using a resident-intruder paradigm, examined the effects of co-administration of cocaine and a typical anabolic-androge nic steroid, nandrolone decanoate, on the development of aggression in male Sprague-Dawley rats. 2. Dose response studies demonstrated that low dose cocaine (1 mg/kg) produced more aggression in a greater perce ntage of animals than for either the controls or groups receiving high er doses (up to 20 mg/kg). Initially, high intermittent doses of nandr olone (20 mg twice weekly) produced more aggression; however, low dail y doses of nandrolone (2 mg) produced greater levels of aggression fol lowing 4 weeks of treatment. 3. Optimal doses of cocaine and nandrolon e, when administered together, resulted in aggression scores that were not significantly different from controls or either drug singly. Howe ver, a greater percentage of animals receiving both drugs exhibited ag gression than did rats receiving either drug alone. 4. These results s upport the interpretation that the drugs interact to produce unique ef fects in the development of aggression. However, the complexity and ex tent of the interactions is great and remains to be fully elucidated.