Innovative technologies such as artificial intelligence (AI) machine learning and optogenetics are accelerating discoveries in life sciences, especially in the field of neuroscience. A new breakthrough study published in Current Biology by pioneering brain researchers at Vanderbilt University used optogenetics and AI machine learning to reveal that dopamine is not just a "pleasure molecule" -- a revolutionary finding that may impact how addiction and psychiatric diseases are treated in the future. "Dopamine deficits are seen in patients suffering from substance use disorder," said Erin Calipari, an assistant professor of pharmacology at Vanderbilt University, and faculty member of both the Vanderbilt Brain Institute and the Vanderbilt Center for Addiction Research. "These individuals have reduced dopamine as well as deficits in decision-making that would be explained by our data and new model. These deficits in decision-making are highly correlated with the severity of addiction as well as predicting treatment outcomes. These data are really key to understanding the relationship between dopamine this disease and figuring out how to treat it."