There are also problems with symptoms of ADHD that can cause some major trouble like depression and anxiety (Steckler & Deskin).The frustrations of dealing with symptoms of ADHD can cause depression and anxiety(Silver) . Also ADHD people outside of school are more likely to show aggression towards others (Gephart). Another reason that ADHD is a problem is that there is no known cause of why it happens but there is theories. There are two theories are the chemical messenger in the brain is not working as well and the brain does not have enough neurotransmitters (Quinn & Stern). A study on ADHD says that there is four genes in people that have ADHD that have higher copy number variations(deleted or duplicates of DNA) (New Gene). All four genes of these are members of the Neurotransmitter glutamate family (New Gene). There are two neurotransmitters in the brain that play a big role in ADHD and they are Epinephrine and Norepinephrine helps transmit physical impulses. Two other neurotransmitters Dopamine and Serotonin play minor roles in ADHD.Dopamine controls how much attention and how passive, a person can be depending on the situation . Serotonin helps to achieve a successful result (Valkenberg). Both dopamine and serotonin are operated by ADHD medicine ("ADHD Genes")Another take on a theory is that there is less activity in the brains with control of concertation with ADHD(Quinn & Stern).
