Narcotics Anonymous (N.A.) is a twelve-step program of recovery from drug addiction, modeled on Alcoholics Anonymous. It describes itself as a nonprofit "fellowship or society of men and women for whom drugs had become a major problem",[1] and it is the second-largest 12-step organization in existence.[2] The program is group-oriented, and is based on the Twelve Steps and the Twelve Traditions, adapted from A.A.

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http://en.wikipedia.org/wiki/Narcotics_Anonymous