The guidelines presented in this document are intended to provide a resource to psychologists interested in the issue of what represents optimal practice in relation to pharmacotherapy. They are not intended to apply to those psychologists who choose not to become directly or indirectly involved in medication management regardless of their level of competency. Some of the guidelines presented in this document are targeted specifically to the population of psychologists with prescriptive authority. Others are considered relevant in any case where the psychologist is actively involved in decision making, whether as a prescriber or collaborator. Still others are considered applicable any time a psychologist is involved in the practice of pharmacotherapy, whether as a prescriber, collaborator, or information provider. Given the unique elements of the population of psychologists who can prescribe on the one hand, and the frequency with which psychologists participate in collaborative and information-providing activities on the other, it was considered important to provide guidelines appropriate to each set of activities. However, it is also important to recognize that a principle of optimal practice may have different implications in the context of active participation versus providing information. In particular, the distinction between active participation and providing information can often be blurred in the practice setting, with a psychologist often playing different roles at different points in the treatment. Given the ambiguity that surrounds these activities, it is urged that these guidelines be read with the understanding that the clearest practice delineation occurs between those psychologists who possess prescriptive authority and those who do not, and that psychologists who do not possess prescriptive authority use critical judgment in determining which guidelines best inform their practice.