Frontal Cortical Volumes Differ by Attention-Deficit/Hyperactivity Disorder Symptom Presentation in School-Aged Children Born Preterm

To investigate whether cortical and subcortical brain volumes differ according to attention-deficit/hyperactivity disorder (ADHD) symptom presentation in school-aged children born very preterm.

This cross-sectional study included 81 children born before 32 weeks of gestation: 64 without ADHD symptoms, 7 with predominantly inattentive symptoms and 10 with combined symptoms, classified using the Vanderbilt parent questionnaire. Magnetic resonance imaging was analysed using FreeSurfer. General linear models were adjusted for gestational age, birth weight, sex and total intracranial volume. False discovery rate (FDR) correction was applied.

Left rostral middle frontal gyrus (RMFG) volume was the only region significantly associated with symptom presentation after FDR correction (partial η² = 0.179; p = 0.030). Adjusted RMFG volume was larger in children with combined symptoms than in those without ADHD symptoms (mean difference, 3610 mm³; 95% CI, 1155-6064; adjusted p = 0.002). The inattentive group had the lowest adjusted mean volume, but the difference from the asymptomatic group was not significant. RMFG volume correlated positively with inattentive and hyperactivity/impulsivity symptom scores. No other regional associations remained significant after correction.

ADHD symptom presentation was associated with left RMFG volume, showing a non-monotonic pattern across groups. Larger longitudinal studies are needed to clarify the developmental significance of these findings.