This protracted failure has prompted my colleagues and me at Columbia University to embark on a radically new approach. The appeal of this new approach is based on the peculiarities of cocaine's effects on the brain. This pathway activates the so-called limbocortical region of the brain, which controls the most basic emotions and behaviors. In preconscious creatures, activation of reward pathways during behaviors as diverse as feeding and copulation aided learning and undoubtedly conferred a survival advantage. The same structures persist today and provide a physiological basis for our subjective perception of pleasure.
Substance abuse is rooted in the normal neurobiology of reinforcement.
Humans and other animals will perform work, sacrifice other pleasures or endure pain to ensure a continuing supply of a drug they have come to depend on. The magnitude of reinforcement differs intrinsically among the addictive drugs. It also rises with the amount of drug that reaches the brain and the speed with which the drug's concentration mounts. Intravenous injection typically provides the most efficient delivery. For substances that can be vaporized, however, such as cocaine in its crack form, smoking is equally effective in producing the experience that addicts want.