Adolescent exposure to methylphenidate has no effect on the aversive properties of cocaine in adulthood

Abstract

Methylphenidate is the most widely prescribed pharmacotherapeutic treatment of AD/HD in children and teens and has actions that are also involved in drug reward and reinforcement. Its clinical use has often raised concerns over the possibility that it could potentiate the risk for later drug-related problems. Animals exposed to methylphenidate during adolescence exhibit attenuated cocaine-induced conditioned place preference, but tend to self-administer cocaine more quickly than controls. A drug's abuse potential, as reflected by self-administration, is thought to be the product of a balance between its rewarding and aversive properties, thus the present research assessed the effects of adolescent exposure to methylphenidate on conditioned taste aversions induced by cocaine in adulthood in 132 male Sprague Dawley rats. Although cocaine induced robust dose-dependent taste aversions in accordance with previous research, there were no effects of adolescent exposure to methylphenidate in spite of evidence that it was behaviorally active. The present results indicate that changes in adult cocaine self-administration are not likely mediated by changes in the aversive response. The possibility that such changes are a function of reductions in reward threshold is discussed.