US National Institute on Drug Abuse
"NIDA's mission is to lead the Nation in bringing the power of science to bear on drug abuse and addiction.
Recent scientific advances have revolutionized our understanding of drug abuse and addiction. The majority of these advances, which have dramatic implications for how to best prevent and treat addiction, have been supported by the National Institute on Drug Abuse (NIDA).
NIDA supports most of the world's research on the health aspects of drug abuse and addiction. NIDA supported science addresses the most fundamental and essential questions about drug abuse, ranging from the molecule to managed care, and from DNA to community outreach research."
Source: NIDA website