Social Dysfunction in ADHD Children Associated With Increased Amygdala Functional Connectivity Instability: A Static and Dynamic Functional Connectivity Study.

AIMS: Social dysfunction (SD) is highly prevalent in children with attention-deficit/hyperactivity disorder (ADHD), yet the underlying neural mechanisms remain poorly understood. The amygdala is a central hub for socio-emotional processing, and altered functional connectivity (FC) may explain the heterogeneity of social dysfunction in ADHD.

METHODS

We examined both static FC (sFC) and dynamic FC (dFC) of amygdala subregions in 53 drug-naïve ADHD with SD (ADHD+SD), 71 drug-naïve ADHD without SD (ADHD-SD), and 72 typically developing controls (TDC). The sFC was computed by voxel-wise correlations, whereas dFC variability was quantified using sliding-window analysis. Group differences were tested with ANCOVA, and group-dependent cluster-symptom associations were examined using interaction models.

RESULTS

No significant group differences were found for sFC. In contrast, dFC variability between the left basolateral amygdala (BLA) and the middle occipital gyrus (MOG) as well as the superior frontal gyrus (SFG) was significantly elevated in ADHD+SD relative to both ADHD-SD and controls, following the gradient ADHD+SD > TDC > ADHD-SD. Interaction analyses revealed a significant group-dependent association between BLA-MOG variability and social motivation, whereas no significant group-dependent associations were observed with core ADHD symptoms.

CONCLUSIONS

These findings suggest that social dysfunction in drug-naive children with ADHD is associated with abnormal dynamic, rather than static, amygdala connectivity. The ADHD+SD subgroup showed increased temporal variability in BLA-centered circuits involving both visual-perceptual (MOG) and executive control (SFG) systems. Furthermore, the group-dependent association between BLA-MOG variability and social motivation suggests that altered amygdala-visual temporal coordination may contribute to heterogeneity in social functioning. These results highlight dynamic amygdala-cortical connectivity as a promising neural feature for characterizing clinically relevant social dysfunction in ADHD.