Attention Deficit Hyperactivity Disorder (ADHD) is one of the most commonly diagnosed childhood brain disorders that can continue through adolescence and adulthood. While experts aren’t sure about the exact biological cause, they do know that ADHD has a strong genetic component. They have specifically determined that the genes that control the levels of certain chemicals in the brain called neurotransmitters have relevance in those with ADHD. There are some developmental differences in the brain structure of those born with ADHD as well. Certain risk factors beyond genetics have been identified, such as, low birth weight, head injuries that effect the frontal lobe, exposure to lead and other environmental toxins. There are some theories that target diet and vitamin deficiency as a contributing factor. Many individuals are not diagnosed with this disorder until adulthood. This doesn’t mean that the patient did not have the disorder during childhood, but it is more likely that their symptoms began to affect their quality of life to the point of crisis once they reached adulthood, causing the patient to seek help.