In recent decades, there has been increasing appreciation that understanding psychopathology requires explanations referring to mechanisms and processes residing at multiple levels of organization, such that higher-level explanations cannot be reduced to lower-level explanations.1 This appreciation is also underway in the area of psychopharmacology, where there has historically been a tendency to explain mechanisms of actions of psychotropics predominantly in terms of receptor actions and neurotransmitter changes. Psychopharmacological research has already begun to remedy that by incorporating the potential explanatory role of higher-level mechanisms and processes and investigating how psychotropics produce a cascade of effects that links neurotransmitters to neural networks to complex behaviors. A pluralistic approach to psychopharmacology makes these developments explicit and recognizes that a restricted focus on interactions between psychotropic effects and disorder mechanisms at a molecular level ignores vital questions. This Viewpoint reaffirms pluralistic developments in psychopharmacology that embrace interactions at multiple levels via multiple pathways with top-down and bottom-up causal influences. Three key points are as follows.