intake and for the maintenance of drug intake which have little initial rewarding value, such as nicotine. Activation of the hypothalamic-pituitary-adrenal axis can potentiate the reinforcing effects of drugs (Piazza and Le Moal 1998). However, this activation can in turn drive amygdala CRF. further exacerbating the development of negative emotional states (Koob and Kreek 2007). Although the initial deficit in a specific functional circuit that drives excessive drinking might be specific to one stage of the addiction cycle, as the transition to addiction progresses, an individual is ultimately likely to show a progressive and generalized loss of control over many, if not all, systems. However, the thesis argued here is that as excessive alcohol intake progresses to Substance Dependence on Alcohol (Alcoholism), a common dysregulated functional element is a reward system deficit.
