A comprehensive multidisciplinary review of the most relevant molecular, genetic, and behavioral approaches used to investigate the neurobiological basis of drug addiction. The authors explore the latest findings on opioid, psychostimulant, cannabinoid, alcohol, and nicotine addiction, provide fresh insights into the genetic basis of drug addiction and the new therapeutic perspectives these have opened. They describe the technology available to generate conditional knockout mice and show how these mice can reveal the molecular basis of opioid, psychostimulant, and cannabinoid addiction. They also review the different behavioral models available to evaluate the rewarding effects of drugs and analyze the genes involved in alcohol dependence.A comprehensive multidisciplinary review of the most relevant molecular, genetic, and behavioral approaches used to investigate the neurobiological basis of drug addiction. The authors explore the latest findings on opioid, psychostimulant, cannabinoid, alcohol, and nicotine addiction, provide fresh insights into the genetic basis of drug addiction and the new therapeutic perspectives these have opened. They describe the technology available to generate conditional knockout mice and show how these mice can reveal the molecular basis of opioid, psychostimulant, and cannabinoid addiction. They also review the different behavioral models available to evaluate the rewarding effects of drugs and analyze the genes involved in alcohol dependence.Part I. Opioid Addiction. Molecular Mechanisms of Opioid Dependence by Using Knockout Mice, Brigitte L. Kieffer and Fr?d?ric Simonin. Molecular Genetic Approaches, Theo Mantamadiotis, G?nther Sch?tz, and Rafael Maldonado. Opiate Addiction: Role of the cAMP Pathway and CREB, Lisa M. Monteggia and Eric J. Nestler. Different Intracellular Signaling Systems Involved in Opioid Tolerance/Dependence, Thomas Koch, Stefan Schulz, and Volker H?llt. Inhibitors of the Enkephalin Catabolism: New Therapeutic TolS@