This application seeks funding for the continuation and expansion of the UCLA Drug Abuse Research Training program (NIDA 1-T32-DA07272), which has grown to maturity since its inception in 1991 and its renewal and expansion in 1995. The numbers, credentials, and qualifications of the pool of applicants have steadily increased, with each new cohort possessing a range of skills that is broader than the previous cohort. The goals of the training program have been met in each year of the program and over the course of the program history. The interdisciplinary, comprehensive training environment sought in the original and renewal applications has steadily coalesced and will be even more thoroughly ingrained with the ongoing addition of more neuroscience-oriented faculty and neurobiological research training opportunities. These enhancements have been successfully integrated into the program, and training has been provided in virtually all areas of drug abuse research, ranging from neurobiology to social policy. The curriculum and the program ethos promote the interdisciplinary training of the fellows, representing a unique training ecology with many ongoing research projects offering fellows considerable opportunity to enhance and broaden their substantive knowledge of drug abuse research, expertise in research methodologies, and practical skills associated with successful scholarship. The informal linkage of UCLA drug abuse researchers created for the current training grant over the past decade served as a formative organizational structure for a much larger substance abuse research entity at UCLA; the amalgamation of affiliated substance abuse researchers at UCLA was formalized in November 1999 into a major institutional research center within the UCLA Department of Psychiatry and Biobehavioral Sciences. This center, the UCLA Integrated Substance Abuse Programs (ISAP), includes 48 M.D. and Ph.D. substance abuse researchers and a multi-site treatment service delivery capacity, making it one of the largest groups in the country specializing in the topic of substance abuse disorders. ISAP will serve as the new organizational home of the training grant continuation requested in this application. The continuation of the training program as the Drug Abuse Research Training Center will advance the field by developing the skills and acumen of the next generation of drug abuse researchers.