The article by Volkow, Fowler, and Wang reviews imaging studies that have provided new insights into the neurochemical and functional changes in the brains of drug-addicted individuals. These studies reveal that chronic drug abuse leads to significant decreases in dopamine function, particularly in prefrontal regions such as the orbitofrontal cortex and cingulate gyrus, which are associated with decreased sensitivity to natural reinforcers. Functional imaging shows that during drug intoxication or craving, these frontal regions become activated in a complex pattern involving reward, motivation, memory, and cognitive control circuits. The authors propose a model where the value of drugs and drug-related stimuli is enhanced at the expense of other reinforcers, leading to a loss of control and compulsive drug intake. This model suggests a multi-pronged approach for therapy, including reducing the rewarding properties of drugs, enhancing the rewarding properties of alternative reinforcers, interfering with conditioned associations, and strengthening cognitive control. The article also discusses the role of environmental and genetic factors in vulnerability to addiction and highlights the need for further research on imaging techniques and the development of radiotracers to better understand the neurochemical changes underlying drug addiction.The article by Volkow, Fowler, and Wang reviews imaging studies that have provided new insights into the neurochemical and functional changes in the brains of drug-addicted individuals. These studies reveal that chronic drug abuse leads to significant decreases in dopamine function, particularly in prefrontal regions such as the orbitofrontal cortex and cingulate gyrus, which are associated with decreased sensitivity to natural reinforcers. Functional imaging shows that during drug intoxication or craving, these frontal regions become activated in a complex pattern involving reward, motivation, memory, and cognitive control circuits. The authors propose a model where the value of drugs and drug-related stimuli is enhanced at the expense of other reinforcers, leading to a loss of control and compulsive drug intake. This model suggests a multi-pronged approach for therapy, including reducing the rewarding properties of drugs, enhancing the rewarding properties of alternative reinforcers, interfering with conditioned associations, and strengthening cognitive control. The article also discusses the role of environmental and genetic factors in vulnerability to addiction and highlights the need for further research on imaging techniques and the development of radiotracers to better understand the neurochemical changes underlying drug addiction.