Anterior cingulate cortex alterations in children and adolescents with Attention Deficit and Hyperactivity Disorder: a systematic review of neuroimaging studies.

Abstract

Purpose: This systematic review investigates existing evidence regarding the structural and functional alterations of the anterior cingulate cortex (ACC) in children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD), a neurodevelopmental disorder characterized by persistent inattention and hyperactivity-impulsivity.

Materials and methods: Following the PICO framework, inclusion criteria specified populations of children and adolescents aged under 18 years. The intervention comprised neuroimaging modalities assessing the ACC, compared against typically developing controls, with neuroimaging findings as the primary outcomes.

Results: Structural MRI findings reported reduced gray matter volume, cortical thinning, and atypical sulcal morphology within the ACC. Functional MRI studies indicated diminished ACC activation during inhibitory control tasks, alongside selective hyperactivation potentially reflecting compensatory mechanisms. Resting-state analyses revealed hypo-connectivity between the ACC and regulatory regions-including the dorsolateral prefrontal cortex, cerebellum, and default mode network-with mixed connectivity patterns suggesting neurofunctional subtypes. Additionally, EEG studies demonstrated attenuated N2/P3 amplitudes and disrupted theta oscillations.

Conclusions: This review demonstrates a coherent neurobiological pattern in pediatric ADHD, characterized by both structural alterations (reduced ACC volume, thickness, and atypical folding) and functional dysregulation (abnormal activation, disrupted connectivity, and altered electrophysiological responses) across tasks probing inhibitory control, reward processing, and resting-state dynamics.