Caregiver strain modulates the association between attention deficit and alpha oscillations in children with ADHD

Introduction: The neurobiological mechanisms underlying Attention-Deficit/Hyperactivity Disorder (ADHD) remain incompletely understood. Existing research has identified abnormalities in alpha rhythm among individuals with ADHD; however, its association with core symptoms lacks consistency, suggesting that enhanced alpha activity may represent a state-dependent compensatory manifestation. The family environment, particularly caregiver stress, is recognized as an important external factor influencing the development of children with ADHD, yet its potential role as a mediator between clinical symptoms and neural brain activity has yet to be systematically explored. Methods: The study included 59 children with ADHD. Correlations among attention deficit scores (ADS), hyperactivity/impulsivity scores (HIS), various dimensions of caregiver strain, and posterior alpha power were analyzed, with Bonferroni correction applied to control for multiple comparisons. Subsequently, hierarchical regression and mediation modeling were employed to examine the mediating effect of caregiver strain. Results: No direct correlation was found between ADS and alpha power. A triangular pattern among symptoms, stress, and brain activity emerged: ADS showed strong positive correlations with all dimensions of caregiver strain, and subjective internalized strain (SIS) remained significantly positively correlated with alpha power even after correction. The mediation model indicated a suppression pattern, wherein the statistical association between ADS and alpha power was consistent with a positive indirect pathway via SIS, alongside a masked direct association, resulting in a non-significant total effect. Discussion: The findings suggest a model in which SIS is a key statistical mediator in the relationship between ADHD symptoms and specific neural oscillatory patterns, and highlight the plasticity of brain function in response to the family emotional environment.