Although MDMA is often touted as being relatively nonaddictive and harmless, there is increasing evidence that there are many health consequences related to its use, especially when used in combination with alcohol or other drugs. Research indicates that long-term brain damage may result from extensive and prolonged MDMA use; MDMA use is apparently spreading from large urban areas on the East and West coasts to rural settings and small communities, making MDMA use and abuse an important emerging issue for Missouri. MDMA is the most popular of the "club drugs," a group of illicit drugs often used in combination with alcohol and other substances at nightclubs and "raves" to enhance capacity for prolonged dancing and to heighten the experience of light and sound; however, recent reports note the rapid spread of the use of club drugs in schools, neighborhoods, and other locales. MDMA use is increasing among teens. After explaining the chemical composition and development history of MDMA, this paper describes the manufacturing and trafficking of MDMA, followed by discussions of its psychological and physiological effects. Indicators of MDMA abuse are presented for the Nation and for Missouri. Suggestions are offered for MDMA prevention, treatment, and interdiction. Regarding policy recommendations, the paper advises that the best State policy model for MDMA blend prevention, treatment, interdiction, and research. Policy recommendations are to inform and educate the public to reduce MDMA use; ensure proper diagnosis and treatment of Ecstasy users; and assess and monitor Ecstasy use at the State level. 1 figure, 1 table, and 36 references