The end of the millennium provides an opportunity to review some of the common practices that were present in psychopharmacology during the 20th century. The author focuses on two approaches that have dominated research and guided the clinical application of psychopharmacologic therapeutics: the unitary clinically-based and single-lesion perspectives. The author expands upon these older formulations of neuropsychiatric disease pathogenesis and describes how the approach to psychopharmacologic research and therapeutics has changed in light of advances in the basic neurosciences. Relevant recent advances in the basic neurosciences that shed light on the pathophysiology of neuropsychiatric disease states and that guide psychopharmacologic practices are described. The use of atypical antipsychotic agents to treat schizophrenia is given as one example of the clinical applications of the approach to psychopharmacology in the next century.