The primary objective of the proposed studies is to provide sensitive, efficient and standardized behavioral evaluations of test compounds that may be useful for the treatment of cocaine abuse and dependence. Studies will be carried out by means of well-established protocols in nonhuman primates. New procedures will be developed if requested by NIDA. Careful records of all compounds tested under both Tasks 1 and 2 will be maintained throughout the contract period as specified by NIDA, and regualr reports will be filed as required. Test compounds provided by NIDA will be tested for their ability to antagonize the discriminative stimulus effects of cocaine.