Attention-Deficit/Hyperactive Disorder, ADHD, has become a topic of debate amongst psychologist, and doctors throughout the years. Withstanding its questionable beginnings and maintaining its place in the DSM-V, ADHD has become one of the most commonly diagnosed disorders in children today. ADHD is believed to have first been mentioned as a disorder in children during the early 1900’s. It had been described as an “abnormal defect of moral control”, a problem with the child’s ability to control their behavior that did not interfere with their intelligence, by Sir George Still (Holland Web). It was, however, not until the second edition of the DSM that a disorder resembling today’s ADHD diagnosis appeared. “Hyperkinetic reaction of…show more content… A predominantly inattentive child will have a harder time paying attention to detail, completing tasks, remembering routine and staying focused. A child demonstrating more symptoms of hyperactivity-impulsive behavior will struggle being still, will be visibly more restless, impatient, and fidget a lot. If enough symptoms of both types are present, the child can be diagnosed with combined type (Facts Web). The symptoms of ADHD can change over time, and the presentation of ADHD a child was diagnosed with can also change. Due to the fluidity of the ADHD diagnosis, the validity in ADHD’s presence has been up for debate. However, ADHD is a neurobiological disorder. There is proof of its biological origins. Through various imaging studies, researchers have been able to determine various areas of the brain that are different in children with ADHD. The caudate nucleus and globus pallidus, areas highly concentrated with DA receptors, the posterior brain, and areas involved in coordinating activities are all smaller in children with ADHD. Specific genes are also being identified in association with ADHD, including: mutations in the human thyroid receptor gene on chromosome 3, DAT on chromosome 5, and DRD4 on chromosome 11. ADHD’s connection to DAT and DRD4 also support findings that deficiency in dopamine lead to a diagnosis of ADHD. The non-genetic causes of ADHD are also