In my previous writing on ADHD I talked about the major characteristics of the disorder, including both the predominant features that determine the diagnosis, as well as other difficulties that research suggests are very much associated with ADHD. That presentation, as well as this one, is considerably informed by the works of Russell Barkley, recognized as one the top researchers in the world on this topic. What I would like to talk about in this presentation is the prevalence of ADHD, the different subtypes, the situational factors that influence the degree of ADHD, and finally, the causes and its treatment. ADHD is found in approximately 3 to 5% of the childhood population, or one in every 25-30 children. Although it was once thought that children outgrew it over time, it is now believed that between 50 to 60% of children with ADHD will continue to have the disorder in adulthood, although its presentation may look quite different. ADHD is seen in all social classes and ethnic groups. It is seen in males more than females, although there is also likely a “referral bias” as boys are more likely to have disruptive and aggressive behaviors compared to girls. Since 1980, ADHD has been broken into several different subtypes, depending on the combination of symptoms that are shown. Children who have difficulties primarily with impulse control and hyperactivity, but don’t have attention or concentration problems, this subtype is referred to as the Predominant Hyperactive-Impulsive Type. Individuals with the opposite pattern, problems with concentration and attention but not with impulse problems and hyperactivity, are known as the Predominant Inattentive Type. However, most people with ADHD show each of these features (poor impulse control and hyperactivity, as well as attention problems), and are referred to as the combined type. Research on the combined type suggests that they're likely to develop their hyperactivity and poor impulse control first, and usually during the pre-school years. In most of these cases they will eventually progress to developing problems with attention span, distractibility and the ability to stick with things within a few years of entering school, and therefore more likely then being diagnosed as having the Combined Type. Of the different subtypes, there is clearly less research on the Predominantly Inattentive Type than the others. Of the research that is out there, more and more people are believing that there is a major difference in the attention problems these children have, compared to those in which hyperactivity and impulsivity are present. The Predominantly Inattentive Type of ADHD seems to be associated with more daydreaming, passiveness, sluggishness and difficulties in filtering important information from information that is not important. Additionally, these children also tend to process information slowly, have mental fogginess and confusion, are more socially quiet or apprehension, and are less likely to consistently retrieve information from their memory. With these children, there is also less oppositional and defiant behavior, conduct problems, and delinquency. Given these lack of problems, however, often times these children are overlooked as having the disorder and therefore less likely to receive treatment. Also, this subtype is far more common in girls than in boys. Although the exact causes of ADHD are not known, it is generally agreed that ADHD is a biological condition resulting from less than optimal functioning in a particular part of the brain.

There are significant differences between the brain functioning in people with ADHD compared to those who are not. In this first picture you see a region known as the frontal cortex, which is the orange colored area

in the picture. This frontal cortex is part of the cerebral cortex, or the outer surface of the brain. ) What we are finding out is that there is a considerable degree of under-activity in the frontal lobe, particularly the prefrontal lobe that is the area right behind the eyes. This is the lobe that is involved mainly with what are referred to as the executive functioning of the brain. It’s responsible for problem solving, attention, reasoning and planning. Recently studies have also shown a decrease in activity in an area known as the basal ganglia, which is the area responsible for regulating movement and is connected to the frontal lobe region. We know that there is under-activity in these areas of the brain because of current brain imaging technology, which now let’s researchers view the brain while it works, like taking a moving picture of it. Let me show you some pictures of what I’m talking about.

In this first picture you see two different brains, on the left a brain that does not have ADHD and

on the right a brain that does. What you’re basically looking at is the blood flow that is occurring. Blood goes to where the action is. The picture on the left shows much more activity of the two. Less blood is needed for the brain on the right side because that area isn’t being used as much; it’s more inactive. And again, this is the area related to problem solving, attention, reasoning and planning. This is a problem with the functioning of the brain. It is NOT based on a choice the child is making. In this final sequence of pictures you see three pictures of an ADHD brain. The image below is when it’s at rest.

The bottom left is when it’s trying to concentrate (note how the activity level actually goes down). On the bottom right it’s when it’s trying to concentrate, but this time is on a stimulant medication.

As mentioned, nobody knows exactly what causes ADHD. Likely, it is a combination of factors. Of the different factors, however, there is little question that hereditary/genetics makes the largest contribution to cause, generally considered to be around 80%. In cases where hereditary does not seem to be a factor, difficulties during pregnancy, prenatal exposure to alcohol and tobacco, prematurity of delivery, significantly low birth weight, and post natal injury to the prefrontal regions of the brain have all been found to contribute to the risk of having this disorder. Research has not supported popularly held views that ADHD is caused from excessive sugar intake, food additives, excessive viewing of television, or poor child management by parents. All of the primary symptoms of ADHD show a significant range across various settings and with different caregivers. The characteristics of a situation often determine how much difficulty ADHD children will have with their behaviors. One of the characteristics is the degree to which parents and teachers make demands on ADHD children to restrict their behavior. When the child is playing on his own or in low-demand settings, it’s often hard to tell their behavior from a nonADHD child. Related to this is the complexity of the task they are asked to do. The more complicated, where they need to plan, organize, and control their behavior, the more poorly they will do. ADHD children also appear to be more compliant and less disruptive with their fathers than mothers, for several possible reasons. Mothers are still the primary caregivers, therefore more likely being the one that puts demands on the child. Also, research suggests that fathers and mothers tend to respond to inappropriate behavior somewhat differently. Mothers tend to reason more with their child, repeat their directions, and use affection as a way of getting the child to comply. Fathers seem to repeat their commands less, reason less, and appear quicker to discipline their child for noncompliance. Also, ADHD children display fewer behavior problems in new or unfamiliar surroundings are when they’re doing something for the first time. Another factor that affects the severity of their symptoms is the immediate reward or punishment for complying with instructions. The sooner there is feedback and the more powerful the reward or punishment, the more it impacts their behavior. I’ll say much more about this in the next segment.

One thing that seems to reduce the degree of trouble ADHD children have in any given situation is the amount of individual attention they get. In one-to-one situations, ADHD children appear less active, inattentive, and impulsive than in group situations where they receive little attention. Related to this is the degree of supervision ADHD children get when doing work. They often show many more problems when they don’t have direct supervision. When instructions are repeated frequently, they perform much better. Finally, fatigue or the time of day may make a big difference on the symptoms one sees. ADHD children generally do much better in the morning, and their classroom behavior is often much worse in the afternoon. It’s true that non-ADHD children of show similar effects of time of day on their behavior, but ADHD children seem to be much more affected than non-ADHD children by fatigue. In regards to the treatment of ADHD, none have been found to cure the disorder, but there are many which can effectively help in managing it. First among these treatments is the education of both the family, and others, about the nature of the disorder and its management. But among the treatments that result in the greatest degree of symptom improvement, research overwhelmingly supports the use of stimulant medication, whose names you might know as Ritalin, Adderall, Concerta, and Focalin as well as non-stimulant medication, primarily Strattera. And let me just say this quickly about the stimulant medications. First of all, nobody knows exactly why they work. What these stimulants do is work on a neurotransmitter in the brain that’s called dopamine. It both increases dopamine, and it inhibits its reuptake to the neuron, both of which increases the activity of the brain that was underactive, or under stimulated if you will.

Psychological treatments, such as behavior modification in the classroom, and parent training in child behavior management plans, have also been shown to be helpful. What is important to realize, however, is that the improvements are generally limited to the setting in which the treatment is occurring, and they do not usually generalize to other settings that are not part of the management program. Additionally, studies suggest, as with the medications that I earlier mentioned, the gains that are made during treatment may not last once treatment is ended. What that means, is that treatment for ADHD must be combined (both medication and psychological treatment) and must be maintained over long periods of time in order to keep the initial treatment gains going. In this regard, ADHD should be viewed like any other chronic medical condition; one that requires ongoing treatment for its effective management, but whose treatments don't get rid of the disorder. The treatment of ADHD requires a team approach that includes the mental health, educational, and medical professions at various points. Treatment should be provided over a long period of time to help those in the ongoing management of their disorder. In doing so, many with the disorder can lead highly satisfactory, adjusted, and productive lives. More on strategies for treatment in the final presentation.