Drugs Influencing Learning and Memory

Abstract

Prior to the 20th century, there were no true scientific studies of the effects of drugs on human memory, only anecdotal information such as De Quincey’s treatise on opium and some scattered clinical observations on the various mental effects of such substances as alcohol, coffee, and anesthetics. The term “psychopharmacology” was coined in 1920 to denote the study of the effects of drugs in experimental psychiatry, but the literature on psychopharmacology remained sparse until the discovery and introduction of the major tranquilizers in the 1950s beginning with chlorpromazine and reserpine. As the psychopharmacology literature began to increase at exponential rates during the 1950s, a subliterature devoted to the effects of drugs on learning and memory processes began to accumulate. Prior to the mid 1960s, most of the subliterature dealt with the effects of drugs on learning processes rather than memory processes since the drug was usually administered prior to a learning task. In addition, much of the literature published prior to 1965 on the effects of drugs on learning and memory processes (animal as well as human) was badly flawed methodologically by the absence of adequate control groups and the lack of double-blind procedures.