BackgroundAttention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting up to 5% of children and adults. Undiagnosed and untreated ADHD can result in adverse long-term health, educational, and social impacts for affected individuals. Therefore, it is important to identify this disorder as early as possible. General practitioners (GPs) frequently play a gatekeeper role in access to specialist services in charge of diagnosis and treatment. Studies have shown that their lack of knowledge and understanding about ADHD can create barriers to care. ObjectiveThis pilot randomized controlled trial assesses the efficacy of a web-based psychoeducation program on ADHD tailored for GPs. MethodsA total of 221 participants were randomized to either a sham intervention control or an awareness training intervention and they completed questionnaires on ADHD knowledge, confidence, and attitude at 3 time points (preintervention, postintervention, and 2-week follow-up). Participants in the intervention arm were invited to participate in a survey and follow-up interview between 3 and 6 months after the intervention. ResultsThe responses of 109 GPs were included in the analysis. The knowledge (P