Abstract: | Abstract Four major hypotheses have been formulated to address the issue of why some people develop compulsive use of particular drugs. These hypotheses include: (1) Drugs that are abused sensitize the motivational systems of the brain such that the behavioral routines for acquisition of the drug become compulsive, (2) Drugs that are abused stimulate the pleasure centers in the brain, (3) People who abuse drugs are naturally in an aversive state that their drug use enables them to escape, and (4) Drugs of abuse are associated with aversive withdrawal phenomena which can be elicited by conditioned stimuli, therefore people continue to take drugs to avert conditioned withdrawal states. This paper examines each of these hypotheses in light of research findings from neurobiology. |