Over the past 15 years, psychologists and neuroscientists have learned a lot about the brain and ADHD, disproving many myths that perpetuated about the condition. Yet discussions about ADHD, in the media and elsewhere, are often still stuck on polarized arguments about whether medications for ADHD are either miracle drugs or deadly poisons. Scientific evidence tends to be ignored. Ask your family or friends these questions about ADHD and see how many they get right:
- At what age does ADHD usually show up and does it ever go away?
- Why do people with ADHD focus very well on a few things they really like to do, but they can’t focus well on other tasks that they know are important?
- Are there any real differences in the development or operations of the brain of a person who has ADHD and someone of the same age who doesn’t have ADHD?
- What is the “chemical imbalance” that people with ADHD suffer from?
Below are brief answers to each of these questions. All are based on evidence more fully summarized and explained in my latest book, A New Understanding of ADHD in Children and Adults: Executive Function Impairments.
1. For decades, official diagnostic criteria for ADHD required that at least some of the symptoms of ADHD had to be noticeable before age 7. In some cases, symptoms of this disorder show up while the child is in preschool or before.
But for many, clear indications of ADHD do not show up until the individual faces the challenges to self-management that arise in high school, college, or beyond. Studies have shown that cases where there is no evidence of ADHD until early adulthood can be just as serious and impairing as those apparent at a much younger age. Sometimes these problems are corrected as the person gets older and completes school, but sometimes they continue or get worse in adulthood.
2. Every child or adult with ADHD whom I have ever evaluated has a few favored activities in which they have no problem focusing, sustaining effort, and utilizing working memory. But they do have such difficulties in almost everything else they do. Sometimes their strong focus is in playing sports, making music, repairing cars, or interacting with video games; sometimes it is in other activities.
Studies have now shown that a fundamental characteristic of ADHD is that it varies according to the context in which the person is functioning. It’s almost like erectile dysfunction of the mind. They perform well if the task is something that actually interests them—something that really turns them on—they’re up for it. If it doesn’t turn them on, they cannot get up for it—they cannot adequately perform. This is due to differences in the chemistry of the brain.
3. Many people notice that all the symptoms of ADHD are problems that everyone has sometimes and that those with ADHD can focus well for activities that interest them. On this basis, they assume that those with ADHD are no different from anyone else except that they are "lazy" or simply lack "willpower."
Studies have shown that there are measurable differences in the brain development and functioning of those with ADHD compared to others the same age. Most of their brain development is similar to that of their peers. However, certain areas of the brain that are critically important for the brain’s management system may be delayed in maturation by three or more years. Many also have problems with development of “white matter” fibers that provide interconnections from one region of the brain to another.
4. The term “chemical imbalance” is often used to explain the impairments of ADHD. This suggests that there are chemicals floating around in the cerebral spinal fluid that are simply not in the right proportions—as if there were too much or too little salt in the soup. Impairments of ADHD are not due to a global excess or lack of a specific chemical within or around the brain. Studies have demonstrated that the primary problem is related to chemicals manufactured, released, and then reloaded at the level of synapses, the trillions of infinitesimal junctions between networks of neurons that manage critical activities within the brain’s management system.
Rapid release and reloading of “micro-dots” of two specific chemicals are necessary for carrying essential low-voltage electrical messages, like sparks from a spark plug across the gaps between neurons. For those with ADHD, those chemicals are not adequately released or are too quickly reloaded to carry those messages efficiently across the neurons, unless the task is especially interesting or scary.
These are just a few of many areas in which the popular understanding has not yet caught up with the science-based understanding of ADHD.
Thomas E. Brown, Ph.D., is the Associate Director of the Yale Clinic for Attention & Related Disorders.