The Etiology of Addiction

This chapter reviews contemporary perspectives on the etiology, or the causes, of addictive disorders. Major progress has been made in understanding the effects of addictive drugs in the brain, leading to a number of influential neurobiological models. One of the earliest theories that shaped neurobiological perspectives was the psychostimulant theory of addiction, which identified a neurobiological common denominator across drugs of addictive potential via increases in dopamine release in the medial forebrain bundle, a neuronal tract within the mesolimbic dopamine pathway. Related cognitive determinants are motives for substance use, the pattern of reasons that a person reports for why he or she uses the drug. The importance of social factors in addiction is readily apparent from the observation that substance use is very commonly a social activity and the proverb that "birds of a feather flock together". Neuroimaging is increasingly permitting insights from preclinical models to be investigated directly in human participants affected by addiction.