Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent disorders among school-going children. The aim of this study was to compare academic achievement of learners with and without ADHD in international primary schools of Mombasa (Kenya) and Kampala (Uganda). A comparative study was conducted among 377 respondents using Attention Deficit Hyperactivity Disorder Scale Questionnaire (SNAP-IV) which assessed the three ADHD subtypes in form of a closed-ended questionnaire. Results revealed that learners with ADHD had low overall academic achievement compared to those without ADHD in Mombasa (p <.001) and Kampala, (p <.001). Boys with ADHD in Mombasa had better grades than girls (M = 168.51, SD = 32.50 vs. M = 160.00, SD = 39.07) while girls with ADHD in Kampala had better grades than boys (M = 103.50, SD = 24.77 vs. M = 93.45, SD = 24.71). Learners with ADHD Inattentive subtype were greatly impaired compared to those with ADHD Hyperactive-Impulsive and Combined subtypes in both cities. ADHD significantly predicted academic achievement with higher variability in Kampala (55%) than Mombasa (10%). Attention-deficit hyperactivity disorder has a negative impact on academic achievement of learners with the condition. The study recommended integration of ADHD screening in school health services to enable early detection and management of the condition.

The study examined