By

Gordon E. Kenney, Ph.D. Licensed Psychologist The University of Memphis Memphis, Tennessee, USA

This graph details lifetime use of five classes of substances between 1971 and 1990 among American adults. At no time has use of any single class of substances presented exceeded 20% of the U.S. population. The most hated and feared substance class of them all, the opiates, has never claimed more than 5% of the population as adherents. Even in 1910, the percentage of American adults using opiates was 0.2%; that is, two-tenths of 1% (Brecher et al., 1972, p. 62). Not presented are usage rates for caffeine, which is due to the lack of reliable information about its longitudinal use among Americans (even NIDA neglects to track caffeine's use in its "National Surveys").