This is a study of beliefs, attitudes, and behavior with regard to a wide range of legal and illegal drugs. Included are data about coffee, tea, tobacco, and illicit drugs such as marihuana and heroin. The report covers the current situation and highlights trends from two prior studies on drug abuse conducted for the National Commission on Marihuana and Drug Abuse. The present survey adds considerable new information reflecting current interests and issues. The report includes summary information of recipient experience with the drugs; user patterns and characteristics; medical usage of psychotherapeutic drugs; findings on other substances such as tea, coffee, cigarettes, and alcohol; and beliefs and attitudes related to drugs. There are also extensive appendices. Findings of the survey include the fact that the public has more experience with marihuana than with any other psychoactive drugs studied, with the next highest being over-the-counter psychotherapeutic drugs. There are strong age relationships connected with the use of marihuana, social use of illicit drugs is the most common pattern, nearly half the adult population report some experience with prescribed psychotherapeutic drugs, and, finally, virtually no change has been reported in adult cigarette consumption over the past several years whereas a marked increase for young people has been noted. (NG)