Synaptosomal-associated protein of 25 kDa (SNAP-25) regulates exocytosis of neurotransmitters and is thought to be involved in the neuropsychiatric disorders such as schizophrenia [14, 15], attention-deficit/hyperactivity disorder (AD/HD) [16, 17], and epilepsy [18, 19]. This evidence concerns the gene SNAP25 and attention deficit-hyperactivity disorder.