Potential biomarker of brain response to opioid antagonism in adolescents with eating disorders: a pilot study

Background Eating Disorders (ED) affect up to 5% of youth and are associated with reward system alterations compulsive behaviors. Naltrexone, an opioid antagonist, is used treat ED behaviors such as binge eating and/or purging. The presumed mechanism action blockade activation; however, not all patients respond, the optimal dose unknown. Developing a tool detect objective drug response in brain will facilitate development therapeutic optimization. This pilot study evaluated neuroimaging pharmacodynamic biomarker antagonism adolescents ED. Methods Youth aged 13–21 binge/purge completed functional magnetic resonance imaging (fMRI) pre- post-oral naltrexone. fMRI detected blood oxygenation-level dependent (BOLD) signal at rest during two probes (monetary incentive delay, MID, passive food view, PFV) predefined regions interest inhibitory control. Effect sizes for Δ%BOLD (post-naltrexone vs. baseline) were estimated using linear mixed effects modeling. Results In 12 (16–21 years, 92% female), BOLD changes following naltrexone nucleus accumbens PFV (Δ%BOLD −0.08 ± 0.03; Cohen’s d − 1.06, p = 0.048) anterior cingulate cortex MID 0.06 1.25, 0.086). Conclusion acute pathway modulation this small sample If validated future, larger trials, task-based by may serve novel therapeutics targeting pathway, enable quantitative pharmacology inform dosing. Clinical trial registration https://clinicaltrials.gov/ct2/show/NCT04935931 , NCT#04935931.