Emotion Regulation Mediates Functional Impairment in Thai Children with Attention-deficit/hyperactivity Disorder: A Cross-Sectional Study

Objective: The study investigated the potential mediating effects of emotion regulation and emotion lability/negativity in the relationship between attention-deficit/hyperactivity disorder (ADHD) symptoms and functional impairment while also examining the associations between ADHD symptoms, emotion regulation, and impaired functioning in different life domains among children with ADHD. Materials and Methods: The clinical sample comprised 118 children diagnosed with ADHD aged 6–12 years. Primary caregivers completed parent reports on symptom severity using the Thai ADHD Screening Scale–Parent Version, assessed emotion regulation and lability/negativity via the Emotion Regulation Checklist, and evaluated functional impairment using the Weiss Functional Impairment Rating Scale–Parent Version. Results: ADHD symptoms correlated negatively with overall emotion regulation (r = −0.515, p < 0.01) and positively with lability/negativity (r = 0.583, p < 0.01). Functional impairment exhibited a negative correlation with emotion regulation (r = −0.649, p < 0.01) and a positive correlation with lability/negativity (r = 0.701, p < 0.01). Elevated ADHD symptoms were linked with increased functional impairment (r = 0.639, p < 0.01). The parallel mediational model showed that emotion lability/negativity partially mediated the association between ADHD symptoms and functional impairment (β = 0.282, p < 0.001), suggesting that ADHD symptoms and emotion lability/negativity indirectly accentuate functional impairment. Thus, heightened ADHD symptoms may exacerbate emotion lability/negativity, contributing to increased functional impairments. Conclusion: Emotion regulation difficulties, particularly emotion lability/negativity, may serve as significant risk factors. Regular monitoring and targeting these challenges hold promise in alleviating adverse functional outcomes co-occurring with elevated ADHD symptoms.