Abstract
Specific learning disorder (SLD) is a neurodevelopmental disorder characterized by difficulties in reading, writing, and mathematics despite normal intelligence. One of the most common comorbidity of SLD is attention-deficit hyperactivity disorder (ADHD). However, differences between patients with SLD alone and SLD with ADHD remain underinvestigated. This study aims to compare clinical and psychosocial characteristics between these two groups. This retrospective study analyzes pediatric psychiatric patient data from Research Electronic Data Capture (REDCap) at the Learning Disorder Outpatient Clinic, Ramathibodi Hospital, Thailand from 2017 to 2023. Chi-square tests, t-tests, and mediation analyses were used to examine group differences and causal relationships among significant factors. Among 251 patients, the SLD with ADHD group exhibited less severe delays in reading (p = 0.003), writing (p = 0.001), and math (p = 0.007). This group also visited the clinic earlier (median: grade 3) than the SLD alone group (median: grade 5). Mediation analysis revealed that ADHD had a direct impact on reading and math delays (coefficients: 0.47, 0.38). No significant differences were found in gender, IQ, birth risks, parental education, or family income. Early detection explained the advantage in writing skills but not fully for reading and math, suggesting that other neurocognitive factors may be involved. Therefore, early recognition and referral should be encouraged to promote better academic outcomes.