Two key strategies for the treatment of drug dependence involve the use of agonists to substitute for the abused drug and the use of antagonists to block the reinforcing actions maintaining drug self-administration. A different strategy for the treatment of drug dependence is outlined, comprising the concurrent administration of an agonist and an antagonist. Concurrent administration of an agonist with an antagonist, in the proper ratio, should produce maximal occupancy of receptors and attenuation of the reinforcing actions of the abused drug. The addict would be relatively "insulated" from the reinforcing effects of the abused drug; at the same time the balance of agonist and antagonist effects is predicted to prevent withdrawal symptoms or intoxication resulting from an under- or over-stimulation of drug receptors. Advantages over the use of agonists alone and antagonists alone, and over mixed agonist-antagonist molecules, are discussed. Application of concurrent agonist-antagonist administration to the analysis of mechanisms underlying nondrug reinforcement and to the treatment of disorders involving receptor disregulation is also described.