This document begins with a brief overview of findings from national surveys conducted by the National Institute on Drug Abuse which show increasing drug use throughout the 1970s and a decreasing trend in drug use during the 1980s. In spite of this decline, drug use in the U.S. is described as still constituting a major public health problem that is pervasive in extent, diverse in its manifestations, and constantly changing. This document presents data on drug use in the U.S. extracted from the 1988 National Household Survey on Drug Abuse, the 1988 High School Senior Survey, and the Drug Abuse Warning Network through December 1988. Summaries of the data from these studies is included in text and data tables which examine trends and demographics for the use of heroin and morphine, heroin and cocaine, cocaine, marijuana and hashish, and phencyclidine (PCP). (NB)