The target universe of NHAMCS includes visits made in the United States by patients to emergency departments (EDs) and outpatient departments (OPDs) of non-Federal, short-stay, or general hospitals. For this report, the 4.1 million ADR ED visits are defined by identifying and combining 3,782,000 visits that indicated alcohol and/or drug problems and 340,000 visits that indicated specific ADR diagnoses. The data show that half of all ADR ED visits were made by patients 25-44 years old. Males had higher rates of ADR ED visits; the highest rates were for black males 25-44 years old. An injury was three times as likely to be classified as "homicide and injury purposely inflicted" in an ADR ED visit compared with all other ED visits. Seventy-six percent of ED visits for suicide and self-inflicted injuries were alcohol and drug related. A quarter of the ADR ED visits were for reasons of symptoms referable to psychological/mental disorders (i.e., depression and neurotic disorders). The treatment and detoxification of patients exposed to alcohol or poison were accomplished with several procedures and/or agents. The most frequently used were gastric lavage, metabolic and nutrient agents to correct complications such as prolonged malnutrition (e.g., thiamine), and adsorption of the toxin on activated charcoal. 17 tables, 4 figures, and 5 references