Adolescence is a critical window for front striatal maturation and iron-dependent dopaminergic function, systems implicated in attention-deficit/hyperactivity disorder (ADHD). Iron is a crucial cofactor in dopamine synthesis and plays a direct role in neurotransmission, brain metabolism, and cognitive functions such as attention and executive control (Cascone, 2023). Recent MRI work using R2*/QSM reports reduced striatal tissue iron in ADHD and links iron load to inhibitory control, supporting its use as a noninvasive biomarker of front striatal maturation (Adisetiyo et al., 2014). Compounding this biology, females are diagnosed less often and later than males, frequently presenting with inattentive or masked symptoms, so objective, I examined whether subcortical iron levels differ by sex in adolescents with ADHD and whether iron relates to performance on an inhibitory control task.

Clinician-diagnosed ADHD adolescents completed an MRI to quantify tissue iron in the caudate, putamen, and thalamus, and performed a Go/No-Go task indexing inhibitory control: d′, mean reaction time. We compared regional iron by sex and tested associations between iron and task performance, including sex-by-iron interaction terms.

Our results showed that significant indication that females with ADHD showed lower tissue iron levels than males across all three brain regions (putamen, caudate, thalamus). Despite iron differences, no statistically significant correlation was found between iron levels and omission scores on the Go/No-Go task. This suggests that brain iron concentration may not directly drive short-term inhibitory performance. To probe the diagnostic shortfall in females, especially those with masked/inattentive profiles, we propose a thalamus-focused extension in the future. 

Nithyasree Mamalayan is an undergraduate student studying neuroscience at the University of North Carolina at Chapel Hill. She is part of the Psychology and Neuroscience department, working in the Cohen Lab. Over this past summer, from June 2025 to July 2025, she received a competitive scholarship awarding her a stipend for independent research.