This Executive Summary is based on findings presented at the 55th semiannual meeting of the Community Epidemiology Work Group (CEWG) held in Atlanta, Georgia, on December 9-12, 2003, under the sponsorship of the National Institutes of Health, National Institute on Drug Abuse (NIDA). The CEWG is composed of researchers from 21 sentinel areas in the United States who have extensive experience in community research and knowledge of their local communities, drugs, and drug-abusing populations, the social and health consequences of drug abuse, drug trafficking and other law enforcement patterns, and emerging drugs within and across communities. Information from national data sources, studies conducted by NIDA grantees, and data from researchers and agency personnel from the city that hosts a meeting are used to enhance findings presented by CEWG members. Drug highlights: Polysubstance abuse, long the hallmark of most drug abusers, continued to proliferate in ever-changing patterns, mirroring the increasing availability of different types and forms of drugs. Methamphetamine abuse continued to spread eastward, and at a pace unrivaled by any other drug in recent times. Heroin indicators remained relatively stable in most CEWG areas, continuing at high levels in northeastem/mid-Atlantic areas, where high-purity heroin powder from South America was available. Other opiate/narcotics indicators increased in most CEWG areas, especially those for hydrocodone and oxycodone. Cocaine, especially crack cocaine, continued to be widely available and a major problem in most CEWG areas. Club drug indicators typically decreased or remained low. Indicators for methylene-dioxymethamphetamine (MDMA), the most frequently abused club drug, either decreased or were stable, while those for gamma hydroxybutyrate (GHB) and ketamine remained very low. However, CEWG members raised issues and concerns about MDMA abuse, based on local studies and community sources. Marijuana abuse indicators remained at very high levels in 2002 and early 2003, even increasing in five CEWG areas. Benzodiazepines, widely abused across all CEWG areas, continued to be used by drug abusers to enhance or control the effects of other drugs. Phencyclidine (PCP) indicators increased in five CEWG areas. (Extract of the publication)