Some current research suggests that ADHD (including the non-hyperactive form) has a lot to do with working memory capacity. Variations on short-term memory game

Some current research suggests that ADHD (including the non-hyperactive form) has a lot to do with working memory capacity. Variations on short-term memory games like Simon appear to improve symptoms when used in a regulated way. There is a Dr administered set called Cogmed that has some good data backing it up. There are also products by Posit Science and Lumocity.