Real-World Functional Gains in Thai Children With Attention-Deficit/Hyperactivity Disorder: A 24-Month Naturalistic Study

Objectives: This study evaluated the 24-month longitudinal trajectories of symptom severity and functional impairment in children diagnosed with attention-deficit/hyperactivity disorder (ADHD). Methods:This longitudinal observational study recruited newly diagnosed children aged 6-12 years from a child and adolescent outpatient clinic.Baseline and subsequent follow-up assessments (6, 12, 18, and 24 months) used the Weiss Functional Impairment Rating Scale-Parent Report to evaluate functional impairment, Thai ADHD Screening Scale to measure ADHD symptoms, and Positive Parenting Questionnaire to assess parenting practices.Comprehensive clinical data capturing treatment compliance, adverse effects, and psychiatric comorbidities were integrated using the Clinical Tracer Plus for ADHD framework.Results: Among 48 participants (median age=8.0years; 83.8% male), linear mixed-effects model analysis revealed that by 24 months, overall ADHD symptoms, functional impairment (d=-0.79),and school difficulties (d=-1.02)significantly decreased, along with improvements in risky (d=-0.41)and social (d=-0.47)behaviors.Although the family and life skills domains improved, these changes were not significant.The child's self-concept domain remained unchanged.Conclusion: Although treatment effectively mitigates core ADHD symptoms and drives significant functional gains, recovery follows domain-specific trajectories.This variability highlights the need to complement standard symptom management with multidisciplinary interventions.Incorporating targeted psychological support and parent management training is essential for modifying negative selfschemas, supporting family dynamics, and translating clinical stability into sustained real-world autonomy.