Resting-state functional connectivity of the sensorimotor network in medication-naïve Chinese children with ADHD:
Han-Lin Li1,2, Meng-Jie Zhang3, Teng Zhu2
1Department of Psychiatry, The First Affiliated Hospital of Zhejiang University School of Medicine Beilun Hospital, Ningbo, China.
Insights
Attention-deficit/hyperactivity disorder (ADHD) involves brain connectivity differences. This study found specific sensorimotor network (SMN) connectivity patterns linked to ADHD symptoms and executive functions in children.
Area of Science:
- Neuroscience
- Developmental Psychology
- Child Psychiatry
Background:
- Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder affecting attention, hyperactivity, and executive functions.
- Sensorimotor network (SMN) dysfunction is implicated in ADHD, but its functional connectivity (FC) patterns and relation to symptoms are unclear due to inconsistent findings.
Purpose of the Study:
- To investigate the patterns of SMN functional connectivity (FC) in medication-naïve children with ADHD.
- To explore the relationships between SMN FC, ADHD symptoms, and executive functions (EFs).
Main Methods:
- The study included 62 children with ADHD and 46 healthy controls (aged 6-15 years).
- Resting-state fMRI was used to analyze FC within and between the SMN, default mode network (DMN), and salience network (SN).
- Network-Based Statistics (NBS) and partial correlations were employed to analyze connectivity and its association with clinical measures.
Main Results:
- Children with ADHD exhibited altered FC within the SMN, and between SMN-DMN and SMN-SN.
- Enhanced intra-SMN FC correlated negatively with hyperactivity/impulsivity.
- Altered SMN connectivity patterns were associated with specific ADHD symptoms and executive function deficits.
Conclusions:
- Distinct SMN connectivity patterns are differentially associated with ADHD symptoms and executive function in children.
- These findings highlight potential neurobiological variations in ADHD but require replication in larger, longitudinal studies to establish causality.
Background:
Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder, often-but not always-characterized by inattention, hyperactivity/impulsivity, and deficits in executive functions (EFs); some individuals may also exhibit sensorimotor dysfunction. While SMN dysfunction has been implicated in ADHD, the patterns of SMN functional connectivity (FC) and their relationships with clinical symptoms and EFs remain inconsistent, partly due to methodological heterogeneity.
Methods:
The study included 62 medication-naïve patients with ADHD (aged 6-15 years) and 46 healthy controls matched for age, sex, and IQ. Clinical symptoms and EFs were assessed using CPRS, IVA-CPT, and Stroop tests. Resting-state fMRI data were acquired, and ROIs within SMN, SN, DMN, and FPN were selected from the Dosenbach atlas. FC was analyzed using Network-Based Statistics (NBS). Partial correlations explored FC-behavior relationships in the ADHD group, controlling for age, sex, and IQ.
Results:
The ADHD group showed significantly higher CPRS hyperactivity/impulsivity scores and poorer IVA-CPT and Stroop performance. Compared to controls, ADHD showed increased FC within SMN (right posterior insula to left precentral gyrus/parietal lobe), between SMN-DMN (precentral gyrus, dorsal frontal cortex, temporal lobe, angular gyrus, posterior cingulate cortex, and precuneus), and SMN-SN (middle insula, superior parietal lobule, superior temporal gyrus, basal ganglia, and fusiform gyrus). Enhanced intra-SMN FC was negatively correlated with impulsivity/hyperactivity and hyperactivity index scores. Enhanced SMN-DMN FC was negatively correlated with hyperactivity symptoms and positively correlated with control quotients in IVA-CPT. Enhanced SMN-SN FC was negatively correlated with Stroop correct responses and positively correlated with omission errors.
Conclusions:
In this medication-naïve pediatric sample, distinct SMN connectivity patterns differentially related to ADHD symptoms and executive function. However, given the cross-sectional design and modest sample size, these associations cannot establish causality; they require replication in longitudinal studies and larger cohorts to clarify whether they reflect developmental variation, neurobiological subtypes, or epiphenomena.
