Researchers at the Center for Therapeutic Community Research (CTCR) in New York City, one of NIDA's major multidisciplinary research centers, are studying a treatment program they devised to meet the complex psychiatric and substance abuse needs of homeless substance abusers who are also mentally ill. They have designed a "modified therapeutic community (TC)" that provides 24-hour-a-day supervised residential treatment for 12 months or more followed by less intense aftercare in which patients live alone or together in apartments and hold down jobs.