DAWN showed no change in the number of drug-related ED episodes or drug mentions for the United States between the first halves of 1997 and 1998. During the same period, the total number of ED visits in the Nation increased 1 percent. Total drug-related ED episodes were stable across gender, race/ethnicity, and most age subgroups; however, total episodes increased among patients age 35 and older. In drug-related ED episodes, overdose was the most often cited reason for the drug-related ED visit, and suicide and dependence were the most frequently cited motives for taking the substances. A comparison of the first halves of 1997 and 1998 showed no change in amphetamine, heroin/morphine, methamphetamine/speed, or PCP/PCP combinations. There was a 9-percent increase in cocaine mentions (from 78,722 to 85,803) and a 16-percent increase in marijuana/hashish mentions (from 32,402 to 37,500). There was a 51 percent decrease in LSD mentions (from 3,677 to 1,797). Total drug-related ED episodes increased in 4 of the 21 metropolitan areas oversampled in DAWN: Atlanta, Dallas, San Diego, and New Orleans. 56 tables, 10 figures, and appended detailed description of DAWN, limitations of the DAWN data, explanation of tables, and glossary of terms