Given the broad evidence that dopamine is essential for attention and working memory [15]–[18] and that the genetic polymorphism in the DAT gene is thought to be implicated in ADHD [31]–[33], it is possible that both attention and working memory might play a role in pattern completion of memory retrieval under the partial-cue conditions through DAT-mediated dopamine regulation. This evidence concerns the gene SLC6A3 and attention deficit-hyperactivity disorder.