The study results are consistent with the central tenet of the incentive-sensitization theory – that motivational (“wanting”), but not hedonic (“liking”) processes become sensitized in the progression to addiction (14). In our study, the individuals who developed AUD over the 10-year period reported increases in wanting alcohol over time, while liking of alcohol remained high but stable over time. The incentive-sensitization theory is based on behavioral and pharmacological studies in rodents demonstrating wanting and liking as distinct components of reward and mediated by separate neural systems. In the animal studies, repeated exposure to the drug produces incremental neuroadaptations in the circuits mediating motivational salience, rendering them hypersensitive to the drug and its associated stimuli (14,44). Until now, however, this idea has not been examined in a longitudinal manner in humans. Although cross-sectional studies of alcohol use severity continuum support this idea (45–49), to our knowledge, our study, which includes repeated alcohol challenge testing in the same participants over an extensive period, provides the first longitudinal support for the central tenet of this theory.
