Drug addiction rehabilitation can be described in three main phases of treatment, each with specific objectives, detoxification and withdrawal alleviation, reduction in drug use, and relapse prevention. Throughout each stage of rehabilitation the impact of drug craving must be addressed and managed in an effective manner. This is perhaps most critical during the relapse prevention phase of treatment, which in many regards is the best measure of treatment outcome success. This proposal will investigate the relationship between treatment outcome and conditioned craving responses in cocaine-dependent patients. It will employ cue-induced cocaine craving studies aimed at evaluating the psychological and neuronal basis of cocaine craving and related cue-induced states, such as arousal, anxiety and cocaine-like high. The primary aim of this study is to test whether positive outcomes in cocaine addiction rehabilitation are correlated with specific reductions in cue-induced cocaine craving. The neurobiological correlates of the chronic effects of cocaine have been well characterized by neuroimaging and quantitative EEG (qEEG) based studies. In addition, psychophysiological studies such as cue-induced cocaine craving provide a functional measure related to cocaine addiction. By combining qEEG measures with cue-induced cocaine craving studies this proposal will develop methods to examine the neurobiological basis of craving in cocaine addiction. The secondary aims of this proposal are to explore the relationships between cue-induced qEEG, psychophysiological and subjective responses, addiction severity and therapeutic outcome.