These molecules mostly target neurotransmitters of ascending systems from the brainstem nuclei, and have been directed to treat cognitive impairments of attention deficit hyperactivity disorder (ADHD), Parkinson’s disease, schizophrenia, while acetylcholinesterase inhibitors are currently used as a the therapy in Alzheimer’s disease (Husain and Mehta, 2011). This evidence concerns the gene ACHE and attention deficit-hyperactivity disorder.