Because impairments in executive functions (EFs), such as working memory, are associated with functional impairments in youth with neurodevelopmental and neuropsychiatric disorders, strategies that target EFs are critical. Neuroplasticity-based cognitive training has been found to improve cognition in youth with ADHD and in adults with schizophrenia. In this trial, the investigators seek to extend the relevance of computerized cognitive training to youth with comorbid ADHD and Tourette Syndrome. Given the literature, the investigators hypothesize that computerized working memory training will produce gains in untrained cognitive tasks and behavioral ratings of executive functions in youth with ADHD+TS. The investigators will assess aspects of attention and executive functions in 30 affected youth and randomize them 1:1 to either neuroplasticity-based cognitive training or enjoyable age-appropriate computer games not intended to improve cognition. Cognition will be assessed again after 30 training sessions over 6 weeks and then again at a one-month follow-up.