The investigators will conduct a randomized placebo-controlled trial of a computerized intervention targeting working memory in 30 children with comorbid Attention-Deficit/Hyperactivity Disorder (ADHD) and Tourette Syndrome (TS).

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.

Inclusion Criteria:

1. The investigators will limit inclusion to youth between the ages of 7-13 who carry current diagnoses of ADHD+TS and who have a treating physician at a Partners affiliated hospital or clinic.
2. The investigators will include youth who have undergone neuropsychological testing in the prior 3 years.

Exclusion Criteria:

1. The investigators will exclude patients with intellectual disability in order to more directly extend the prior literature to the ADHD+TS population.
2. The investigators will exclude patients with severe tics as evidenced by a score of > 30 on the clinician administered Yale Global Tic Severity Scale (YGTSS).
3. The investigators will exclude patients with moderate to severe Obsessive Compulsive Disorder (OCD) symptoms, as evidenced by a score of >30 on the clinician administered Children's Yale-Brown Obsessive Compulsive Scale (CYBOCS).
4. The investigators will exclude patients treated with neuroleptics, given that these medications can be cognitively dulling and sedating and potentially lead to secondary working memory impairments.
5. The investigators will exclude families who do not have a computer with an internet connection in their homes, and in which neither a parent nor the child has an email address to receive study related communications.
6. The investigators will exclude families who anticipate or are likely to have a change in therapeutic treatments (i.e., psychotherapy or psychopharmacology) during the time frame of the trial.

NOTE: Patients treated with ADHD medications will not be excluded, but medications will be recorded for covariate analysis.