The beliefs a person has about the effects a drug will have are called expectancies. The study of expectancies began with the employment of the experimental balanced-placebo design in alcohol research in the early 1970s (see Marlatt & Rohsenow, 1980, for a review). Research on people ranging from light drinkers to inpatient alcoholics revealed that expectancies are predictive of some of the behaviors exhibited when people use a drug. These studies revealed that both the beliefs an individual has—about whether a drink contains ALCOHOL and the specific outcomes that individual expects from consuming alcohol—are in many cases more predictive of subsequent behavior than the pharmacological effects of the drug.

Examples of Research Study

An example of research using balanced-placebo design is as follows: In a simulated bar setting, half the participants in a study are told they will receive a drink containing vodka and tonic, and half are...