ABSTRACT
This chapter narrows the lens of focus to the more microlevel—seeing the physiological impact that substances have on people. We cannot deny that drugs impact people—emotionally, behaviorally, and physiologically. Accordingly, the goal of this chapter is to present information on how and where drugs act in the brain, as well as how they can temporarily or permanently change brain function. We will also briefly review the particular neurobiological effects of commonly abused substances. Here, we focus on a special classification of drugs—psychoactive drugs, which are drugs that alter mental functioning. Because of their ability to alter mood, psychoactive substances are developed and widely used to treat mental disorders (such as depression). However, because of these same properties, psychoactive drugs are also commonly abused and can be biologically addictive.
