by Elisabeth Nations
Drug addiction begins with an individual’s pursuit of pleasure and reward, but as time goes on and drug use is repeated and increased, its association with the brain changes. Neural activation by drugs moves from an individual’s ventral stratium to the dorsal stratium, where drug-seeking is then maintained and made into a habit. After this, the habit of drug use isn’t affected by reward as much, and a person is unable to make much of an evaluation of the consequences of his actions. Continual exposure to drugs makes habitual use easier and more likely, as does stress.
This chapter was at times difficult to read, mostly because I felt confused about how the different neurological concepts fit together. Although it seems clear that Lende is attempting to argue that environmental factors play a large role in drug addiction, I feel that he did not spend enough time discussing these factors. In particular, what cultural or social factors might lead a person to use drugs in the first place, and why might that person return to drugs over time, other than because of a neurological pull to do so? Overall, though, I thought Lende explained the concept of incentive salience and its connection to the attraction to repeated drug use well, and I certainly felt that I gained a better understanding of drug addiction by reading this chapter.