Attention-Deficit/Hyperactivity Disorder (ADHD) and Reading Disorder (RD) are the two most prevalent neurocognitive disorders diagnosed in childhood, and they frequently co-occur in the same individual. Despite advances in the development of effective treatments for the two separate disorders, few well-controlled studies have been undertaken to address the question of what constitutes effective treatment for these disorders in combination. Children with ADHD+RD are at risk for being treated ineffectively, even by the best available treatments for the separate conditions of ADHD and RD. which are typically provided independently by health and education agencies, respectively. This is because the best treatment approaches for ADHD do not have any direct beneficial effects on the core cognitive deficits underlying RD. and the best intervention programs for RD do not have any impact on the cognitive and behavioral deficits underlying ADHD. The broad objectives of the proposed project are to develop effective treatments for children with comorbid ADHD+RD by refining and integrating promising intervention approaches for ADHD, RD. and ADHD+RD that are currently being evaluated independently at the University of California (Irvine) and The Hospital for Sick Children (Toronto). These interventions are unique in that they target specific cognitive deficits in ADHD+RD. Specific aims are to: 1) standardize two novel intensive remediation programs that teach specific reading strategies (PHAST') or arithmetic and metacognitive strategies (SCORE) that differentially target specific cognitive deficits in ADHD+RD; 2) standardize the medication protocols for once-daily dosing (OROS-MPH) or twice-daily dosing with methylphenidate; 3) standardize teacher-consultation protocol to promote transfer of specific reading strategies or generalized metacognitive strategies to the regular classroom; 4) estimate intervention parameters (effect size, response rate, attrition rate) from a preliminary evaluation of the relative efficacy of PHAST and MAST in combination with teacher consultation and either OROS-MPH or IR-MPH for improving reading and core ADHD symptoms in children with ADHD+RD; and 5) develop and standardize procedures for implementing and evaluating the intervention in a cross-national multi-site controlled outcome study, including web site development for resource support, video-conferencing, treatment fidelity monitoring, and on-line collection of data. The anticipated outcome is a protocol which is ethically, scientifically sound, and ready to be implemented in a large-scale multi-site randomized controlled trial to investigate the relative effects of these specific intervention approaches on the core cognitive and behavioral deficits in children with ADHD+RD.