The frontal regions of brain weigh consequences of future actions with the decisional balance requiring attention and activation of multiple brain circuits. The prefrontal cortex (dlPFC), includes as well as projects to anterior cingulate cortex (ACC) and the OFC with all 3 projecting to the ventral striatum (VS) a dopamine rich area important for expression of behaviors (Fig. 1). dlPFC, ACC and OFC all contribute to executive functions and inhibition of impulses. Limbic regions including the AMG and entorhinal cortex (ENT) also project to VS, which projects to globus pallidus (GP) and thalamus (Thal), which then projects to multiple brain regions for expression of behaviors. Impulsive behaviors are poorly conceived, prematurely expressed, unduly risky or inappropriate to the situation that often results in undesirable consequences. Expression of impulsive behaviors result from a deficit in suppressing responses, poor evaluation of consequences and an inability to forgo immediate small rewards in favor of greater delayed rewards. Craving drugs is a learned behavioral repertoire, possibly learned early in life and strengthen through repetition. Likely craving represent limbic subconscious drives. Thus, addiction is likely
