Dopamine and food addiction: lexicon badly needed.

Over the last few years, the concept of food addiction has become a common feature in the scientific literature, as well as the popular press. Nevertheless, the use of the term addiction to describe pathological aspects of food intake in humans remains controversial, and even among those who affirm the validity of the concept, there is considerable disagreement about its utility for explaining the increasing prevalence of obesity throughout much of the world. An examination of the literature on food addiction indicates that mesolimbic and nigrostriatal dopamine systems often are cited as mechanisms that contribute to the establishment of food addiction. However, in reviewing this literature, it is important to have a detailed consideration of the complex nature of dopaminergic involvement in motivational processes. For example, although it is often stated that mesolimbic dopamine mediates reward, there is no standard or consistent technical meaning of this term. Moreover, there is a persistent tendency to link dopamine transmission with pleasure or hedonia, as opposed to other aspects of motivation or learning. The present article provides a critical discussion of some aspects of the food addiction literature, viewed through the lens of recent findings and current theoretical views of dopaminergic involvement in food motivation. Furthermore, compulsive food intake and binge eating will be considered from an evolutionary perspective, in terms of the motivational subsystems that are involved in adaptive patterns of food consumption and seeking behaviors and a consideration of how these could be altered in pathological conditions.