By Michelle Jaffee
Sara Jo Nixon, Ph.D., chief of UF addiction research and director of UF’s CARE Center, has been elected a 2025 AAAS Fellow, an honor recognizing the highest levels of scientific achievement.
Below, the Anadarko, Oklahoma, native discusses her career path and her progress in 20 years as an MBI researcher.
Did you always know you wanted to be a scientist?
Early on, I thought I’d be a musician, and I started as an oboe major at Southwestern Oklahoma State University. But the reality of being on campus made me wonder if this was really what I wanted to do. So, I revamped my entire schedule, enrolling in conventional science courses. Eventually, I changed my major to psychology and minored in chemistry. I kept up with music by playing in the orchestra, taking oboe and viola lessons and being a flag twirler and pompom dancer in the marching band. The course that secured my interest in psychological science was one in conceptual modeling and theory: I fell in love with the idea of constructing experimental designs and models to interrogate the brain-behavior relationship. I really like asking questions — probably even my first-grade teacher would say that.
When did you become interested in studying addiction?
At the University of Oklahoma Health Sciences Center, I had the opportunity to do postdoctoral training with Dr. Oscar A. Parsons, who was extraordinary in his field. He worked in addiction, and he had done a lot of the early work looking at neuropsychological impairment associated with chronic substance use, specifically alcohol. The singular turning point for me was accepting that position, because it allowed me to focus on research and build an emerging career. It was a wonderful experience; I stayed on and became an endowed chair there.
Can you describe the projects most important to you?
I’m really proud that we’ve been able to focus on the impact of alcohol and other substances in older adults, even those who don’t have a substance use disorder. Ours is one of the only labs in the country to do this. We’ve had a chance to give talks about these issues nationally and internationally, and it’s very rewarding. Even non-problem levels of drinking can have a huge impact on quality of life and cognition. As a whole, I hope our work will serve to help mitigate the stigma of substance use disorders — that people can see it isn’t just a matter of willpower, and it isn’t that there’s a motivational deficit. Rather, there are real changes in brain structure and function that must be taken into account.
A separate line of research focuses on emotion processing in people with substance use disorders, an effort to identify ways to improve this critical component of effective interpersonal interactions and quality of life. Also, while much of our work has focused on alcohol, our projects are not limited. The use of multiple substances is the predominant pattern. Our studies provide the opportunity to explore the relative impact of multiple drugs, a strategy with a significant advantage. For example, we just concluded data collection of healthy adults aged 65 to 80 who are non-problem alcohol drinkers, and while we didn’t select participants on the basis of cannabis use, we found that over 20% report using cannabis regularly. We’re excited that continued work in older adults will address significant issues for both individual health and public health and policy.
Is it that brain structure and function cause alcohol use disorder, or that the disorder has consequences on the brain?
There are temperament traits that seem to place people at risk: risk-taking and novelty-seeking, for example. We also know that a family history of alcohol use disorder increases risk for the condition. That said, people can develop alcohol use disorder or other substance use disorders in the absence of such risk. Studies like the ABCD Study, a landmark project for which the University of Florida is a site, will shed light on individual differences in neurodevelopment and risk for such outcomes. We haven’t had such comprehensive prospective studies before; we haven’t known what the brain looked like before individuals began using various substances. Now we will.
Perhaps the most straightforward answer is there are heritable traits and a host of other factors that affect risk, but chronic substance use may also change the brain and possibly exacerbate the impact of a predisposition. It’s also really important to remember that the brain is amazingly resilient, and with recovery from substance use disorders, there is a remarkable opportunity for improvement in brain functions as well.
Do you still play music?
I do sing in my office, with my headphones on, to Cecilia Bartoli, an Italian opera singer. I’m sure people out in the hall must be thinking, “Please, send her home.”