Theories of compulsive drug use: A brief overview of learning and motivation processes

Neuroscientists continue to grapple with the conundrum of compulsive drug use. Why do compulsions to seek addictive drugs persist in the face of diminishing pleasure and escalating negative consequences? This chapter surveys several influential theories which look to learning and motivation processes to address this question. Discussed in turn are the possibilities that compulsions arise from: (1) maladaptive prediction error processing, (2) heightened incentive salience via sensitization of drugs and drug-associated cues, (3) the aberrant emergence of habitual control at the expense of goal-directed behavior, (4) Pavlovian instrumental transfer effects and/or (5) a lack of sensitivity to punishment. In each instance we present behavioral evidence derived primarily from Pavlovian and instrumental conditioning experiments, as well as neurobiological evidence derived from manipulation and measurement of the mesolimbic dopamine system. We note limitations and outstanding questions and encourage an integrative approach, whereby computational modeling techniques are employed to combine and compare theoretical assumptions.