There are two competing paradigms attempting to explain the phenomena of addiction: Addiction as compulsion and addiction as choice.  The compulsion model describes addiction as a brain disease in which alcohol and drug use cause neuroadaptations, resulting in uncontrolled drug seeking behavior. The choice model describes addiction as pathology of reinforcement that is contextually dependent upon the availability of meaningful and rewarding alternatives in the choice environment. Dr. Matt Field describes each model and their respective bodies of research.  Dr. Matt Field is a Professor in the Department of Psychology at University of Sheffield.