Abnormal Neurochemical Transmissions
Scientists can't measure the biochemicals that influence the brain's neural transmissions directly. Imbalances in these chemicals can be inferred, however, from reduced numbers of neurotransmitter metabolites in the urine and blood, from differences in cerebrospinal fluid, and from observing how drugs that alter brain chemistry subsequently affect attention, learning, and behavior.
Oddly enough, inattention and hyperactive-impulsive behavior are known to be related to brain underarousal rather than overarousal. When these children talk, read, or engage in activities that require focused attention, they don't experience the same degree of increase in blood flow or glucose utilization in the brain that normally supports these activities. Underarousal also means a diminished supply of the chemicals needed to inhibit activity. As a result, these individuals can't activate attention to high enough levels to focus attention, and they can't activate inhibitory mechanisms to screen out distractions. Once something has grabbed their attention, they can't stop themselves from paying attention or responding.
If underarousal is the problem, then stimulants should be the solution. In a majority of cases, stimulants do help. Many children with any of the three forms of ADHD focus attention better, concentrate, memorize better, are less restless, and refrain from mentally, physically, or verbally responding to irrelevant diversions when they take stimulant medication. The medication seems to heighten the sensitivity of the brain's sensory and attending systems to incoming stimuli, thereby
The most common stimulants used to deal with the symptoms of ADHD are Ritalin (methlyphenidate), Adderall (a combination of amphetamine and dextroamphetamine), CyIert (magnesium pemoline), and Dexadrine (dextroamphetamine). Seventy to 80 percent of children receiving stimulant medication appear to improve to some degree.
As beneficial as these medications are, they have side effects, including insomnia, decreased appetite, weight loss, irritability, lethargy, and abdominal pain, though these tend to diminish within a few weeks. Also observed at times are headaches, drowsiness, sadness, nausea, nightmares, pallor, increased pulse and blood pressure, apathy, a serious facial expression and hollows under the eyes, fearfulness, a dazed appearance, anxiety, and increased talkativeness. Stimulants can induce Tourette's syndrome in individuals at risk. Despite concerns expressed by parents, only one long-term study has documented a link between taking stimulants and substance abuse as an adult. Some growth and weight suppression may occur for a time, but the child does eventually reach his or her expected height and weight. Until recently, "drug holidays" were recommended during school vacations to encourage growth rebound. Because it was found that growth eventually catches up, however, many experts now recommend that children should remain on medication all the time, with drug holidays being given only to teenagers showing serious stimulant-associated growth delays. They reason that it is important for the child to be thinking and behaving as intelligently as possible, as often as possible, even when on vacation. After all, learning does not occur only in the classroom.
Not all children respond to stimulant medication; some 20 to 30 percent show no effect or actually get worse. Moreover, drug dosage is an issue. Children differ regarding the best dosage for optimal thinking. Drug dosage should be decided based on optimal school productivity and learning, even if hyperactivity and other disruptive behaviors are not quite alleviated. In general however, both learning and behavior will improve as standard dosages increase.
Another concern about dosage is that attention, thinking, and behavior seesaw as short-acting drugs reach their peak effect within 1 or 2 hours after taking the medication, and wear off about 2 or 3 hours later. Moreover, at times these children experience a rebound effect as the stimulant wears off, becoming even more active and irritable than they were before taking the medication. If rebound occurs around bedtime, the child may require another dose to calm down enough to permit sleep. Longer-acting slow-release agents (up to 8 hours) help avoid this 4-hour up-and-down cycle, though their effectiveness may not be as powerful. When individuals do not respond favorably to stimulants, physicians have found that tricyclic antidepressants, the antihypertensive clonidine, or monoamine oxidase inhibitors can be effective for some.
Studies prove that stimulant medication can significantly improve attention span, activity level, motor performance, and productivity, accuracy, and persistence in the classroom. However, stimulant medication has been associated with only modest improvements in long-term academic achievement levels and social adjustment.
© ______ 2004, Merrill, an imprint of Pearson Education Inc. Used by permission. All rights reserved. The reproduction, duplication, or distribution of this material by any means including but not limited to email and blogs is strictly prohibited without the explicit permission of the publisher.
Washington Virtual Academies
Tuition-free online school for Washington students.
- Coats and Car Seats: A Lethal Combination?
- Kindergarten Sight Words List
- Child Development Theories
- Signs Your Child Might Have Asperger's Syndrome
- 10 Fun Activities for Children with Autism
- Why is Play Important? Social and Emotional Development, Physical Development, Creative Development
- The Homework Debate
- Social Cognitive Theory
- GED Math Practice Test 1
- First Grade Sight Words List