ADHD is a medical neurobiological disorder. It is an deficit of the nervous system most often due to genetic or biological factors. Studies have found that heredity is the most common cause of ADHD. Medical research has shown that some dopamine genes have been found to be associated with ADHD. If a child has ADHD there is five times more likelihood that another family member will also have the disorder. While ADHD symptoms may be caused by injury to the brain, or exposure to alcohol, nicotine or lead in the developing brain, this is not the cause in the vast majority of children with ADHD.
ADHD is a chronic condition that can present at all levels of severity and rarely occurs by itself. There are three core symptoms, the inability to regulate attention, the inability to regulate activity, and difficulty with inhibitory behavior resulting in impulsivity. However, difficulty with regulating emotions is often an issue as well. It is important to note that symptoms of ADHD can vary from day to day and hour to hour, and while many children may exhibit these symptoms, it is the degree of presentation, the inability to regulate them and a level of impairment, that results in a diagnosis.
Research has shown us that children with ADHD often have weaknesses in the areas of executive functioning (EF). Executive functioning is the mental process that allows us to plan ahead, evaluate the past, start and finish a task and manage our time. Executive functioning skills enable us to: identify a problem, find solutions, organize ourselves, regulate our behaviour and emotions, control our attention levels and resist distractions. Working memory, an important part of executive functioning, is a skill that allows us to keep information in the brain and work with it at the same time. Working memory directly impacts reading comprehension, written expression, math skills and the ability to pay attention and resist distraction. Students with ADHD also frequently process information coming in and going out at a slower speed. Children with deficits in these areas, are frequently mislabelled as being unmotivated, defiant, and lazy.