An anxiotropic agent is one that modifies anxiety, a human emotion that has homologous processes in animals. In psychopharmacology anxiotropic agents consist of two categories of psychoactive drugs: anxiolytics that reduce anxiety and may be used therapeutically, and anxiogenic compounds that increase anxiety.
Most anxiolytic agents are minor tranquilizers, the founding compound of which was meprobamate, marketed in the United States as Miltown. Meprobamate was eventually eclipsed by the benzodiazepines. The target of both categories of anxiotropic compounds is the GABAA receptor.
Globally, the two most widely used psychoactive drugs are anxiotropic agents: ethanol, an anxiolytic, and caffeine, an anxiogenic. While intake of both ethanol and caffeine has been shown to exert an anxiolytic effect, their withdrawal is associated with anxiogenic effects.