Dr. Leibowitz is interested in understanding the neurobiology of substance abuse and addiction. She and her colleagues study the most commonly abused substances, namely alcohol and nicotine, in addition to palatable fat- and sugar-rich foods that may have addictive-like properties. Her current research investigates neural mechanisms that mediate the transition from casual use to abuse and ultimately dependence on these substances. It reveals marked similarities between neurochemical mechanisms in different brain areas that control the consumption of fat, alcohol, and nicotine and also various emotional behaviors, such as novelty seeking, impulsivity, and anxiety, which promote their consumption.
Substance use disorders are heterogeneous in nature, with users exhibiting different patterns of intake varying from cycles of bingeing to chronically elevated intake. Dr. Leibowitz’s research links these patterns to distinct neurochemical systems. It demonstrates that individuals prone to abusing these substances, identified by particular behaviors and biomarkers, exhibit specific neurochemical abnormalities that may be causally related to their excessive consumption. Abusers are highly susceptible to relapse, and her findings associate this with specific neuroadaptations that come to precede bingeing behavior and persist in the absence of substance exposure. Dr. Leibowitz finds that exposure to fat, alcohol, and nicotine early in life, before puberty or during pregnancy, induces this predisposed phenotype in the offspring. Her recent studies suggest that this is attributed to a similar stimulatory effect of these substances on neurodevelopment, neuroimmune function, and lipid metabolism.
With the diversity of mechanisms underlying substance use disorders in adults, her research is focusing on developing methods for prevention of early exposure and brain reprogramming, early detection of abuse propensity, and personalizing pharmacotherapy for distinct subpopulations of prone or addicted individuals.