What FDG-PET Studies Show
Brain imaging using fluorodeoxyglucose positron emission tomography (FDG-PET) has produced suggestive but inconsistent evidence linking ADHD to altered cerebral glucose metabolism, with the most reproducible findings implicating fronto-striatal and premotor circuits. However, results vary substantially by age, sex, task, and study design, and chronic stimulant treatment does not produce robust metabolic shifts even when symptoms clearly improve. No FDG-PET signature is currently sensitive or specific enough to diagnose ADHD, and the technology remains a research tool rather than a clinical instrument.