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What We've Learned About ADHD

Are you up to date on ADHD research?

Thomas E. Brown, Ph.D., has thought deeply about ADHD, basing much of his research on the science of distraction. After serving 20 years on the faculty of Yale Medical School, he now teaches at Keck Medical School at the University of Southern California. In addition, he is the director of the Brown Clinic for Attention and Related Disorders, based in Manhattan Beach, California, as well as the author of the recent book Outside the Box: Rethinking ADD/ADHD in Children and Adults-A Practical Guide.

Source: Pavlen/iStock
Source: Pavlen/iStock

Here are 20 questions and answers on this topic:

Doesn’t everybody have ADHD? Everybody gets distracted sometimes and nobody is always listening carefully.

Some of the characteristics of ADHD are found in everybody—sometimes. But those who really have ADHD have a lot more trouble than most others their age in getting started on tasks they need to do and in staying focused and then shifting focus as needed. It’s tough for them to keep themselves working to finish their assignments and to regulate their sleep and alertness. ADHD is really a complicated set of problems with the brain’s self-management system, its executive functions. ADHD occurs in about 8 to 9 percent of children and about 4 to 5 percent of adults in the U.S.

How can people with ADHD be really good at focusing to play a sport or a video game or to make art or play music, yet not be able to focus on other things they need to do? Is it just a problem with willpower?

ADHD looks like a problem with willpower, but it really isn’t. It’s a problem with the dynamics of the chemistry of the brain. It’s like having erectile dysfunction of the brain. If an activity really turns a person with ADHD on, they’re “up for it” and can perform. But if that activity doesn’t turn them on, it’s really difficult for them to perform. The brain chemicals that motivate action simply don’t activate effectively except for activities that really turn the person on or scare them.

Don’t you have to be “hyper” or have some behavior problems, at least when you were a kid, in order to have ADHD?

No, many of those who have ADHD have never had any “hyper" or behavior problems. Some are more like a “couch potato” and some are quiet and shy. The primary problem for those with ADHD is “attention” broadly conceived as including a syndrome of “executive functions” which involve motivation, short-term working memory, regulating emotions, sustaining effort, and other self-management functions.

Isn’t ADHD mostly a male thing? Not many women or girls seem to have it.

During childhood and adolescence, three boys are identified with ADHD for every one girl; however, the number of women diagnosed with ADHD in adulthood is almost equal to the number of men with that diagnosis. Reports from women seeking treatment for ADHD indicate that many of them have suffered for many years with undiagnosed ADHD prior to their getting old enough to seek treatment for themselves.

What is the cause?

Usually, it’s inherited. It tends to run in families. Out of every four diagnosed with ADHD, one has a parent with ADHD; the other three usually have a grandparent, uncle, aunt, or sibling who has or had ADHD. Often it’s hard to know who has had it because for many years doctors did not know how to recognize it. Even today the diagnosis is often missed.

Doesn’t a person have to get ADHD when they’re very young? It never starts in adolescence or adulthood—or does it?

For decades, it was assumed that ADHD always starts during childhood, but recent longitudinal studies of individuals carefully evaluated and found to not have ADHD during childhood showed that a significant percentage turned out to have developed ADHD impairments by midlife. This may be due to their having ADHD impairments that were not very noticeable until they met challenges for self-management that arise only in adulthood, or it may be delayed action of genes, or both.

Is there any real scientific evidence for ADHD?

There is strong, objective, scientific evidence that ADHD is highly heritable, that individuals with ADHD experience delays of 2 to 3 years or more in development of specific areas of the brain that support executive functions, that ADHD is associated with unique weaknesses of connection and communication between regions of the brain and that it is associated with different patterns of cortical thinning, and that treatment with approved medications improves ADHD symptoms during the times the medication is active in about 70 to 80 percent of those affected.

Does a person ever outgrow ADHD or does it always continue for a lifetime?

Follow-up studies show that about 75 percent of individuals with ADHD in childhood continue to experience significant ADHD-related impairments into adulthood. However, about 25 percent no longer have significant impairment from ADHD during adulthood. For those whose ADHD-related impairments do not persist, there are some measurable differences in brain development relative to those who continue to experience impairment from ADHD.

How can someone who has a high IQ and has been very successful have ADHD? I have a friend who is in a very competitive law school who claims he has ADHD and gets medicine prescribed for it.

Many studies have demonstrated that some children and adults with high IQ have ADHD. Despite their intellectual strengths, they tend to have significant weaknesses in working memory, processing speed, motivation, and other aspects of ADHD that are independent of their other cognitive abilities and often interfere with their ability to deploy those strong abilities. Sometimes their ADHD problems don’t show up until they encounter challenges of college, more advanced education, or taking responsibility for a complicated job.

Is ADHD just an attention and memory problem? Someone told me that it involves problems with emotions, too.

Research has revealed that emotions, mostly unconscious emotions, attached to the individual’s personal store of unconscious memories and learning, are the primary basis on which each person’s brain determines moment-by-moment motivation—what is, at that moment, interesting and important, or not, to that individual. Also, many with ADHD have chronic difficulty in modulating the expression of their emotions

Is it true that ADHD can be diagnosed objectively with a brain imaging test?

No, there has been significant research using brain imaging such as MRI or fMRI to gather information about differences between brain development and functioning in children or adults with ADHD vs. those who don’t have it. But at present, there is no imaging test that can diagnose ADHD reliably. Researchers don’t yet have a way to take an imaging “snapshot” of the brain and, from that, determine whether that brain has ADHD problems in the multiple activities of daily life.

How can ADHD problems be adequately assessed and diagnosed?

Impairments of ADHD are demonstrated over time in many diverse activities of daily life. They cannot be assessed adequately by any blood test, computer test, or neuropsychological tests done over a short time in an office. Adequate assessment requires an adequately trained specialist systematically gathering information from self-report and others about the person’s life situation, health, education, and many aspects of daily functioning over time and in various settings, relative to others of comparable age. A normed rating scale should also be utilized.

Isn’t treating ADHD with stimulant medications more dangerous than not treating ADHD. Aren’t those medications addictive?

Medications most often used to treat ADHD are controlled by the government because if abused by taking excessive doses, they can become addictive. This causes some people to fear that even well-controlled dosing could cause addiction.

But research has shown that a child with ADHD not treated with appropriate medication has double the risk of developing a substance use disorder at some time in comparison with a child who does not have ADHD. Those treated appropriately with medication for ADHD have no more risk of having a substance use disorder in adolescence than would someone without ADHD.

How is ADHD related to learning disorders or other psychiatric disorders?

Research has demonstrated that an adult with ADHD has six times the risk of having at least one additional learning or psychiatric problem that warrants diagnosis at some point in his or her life. This is because the executive function impairments of ADHD often underlie other disorders. Unfortunately, clinicians often diagnose and treat other disorders with which they are more familiar, such as anxiety, depression, dyslexia, mood disorders, or substance use disorders, but do not recognize an underlying ADHD that may require treatment to help the individual to attain adequate functioning

Who is trained and qualified to diagnose and treat ADHD effectively?

Most medical and mental health professionals, including psychologists, psychiatrists, and other physicians, have had very little or no professional training in the assessment or treatment of ADHD, especially in adolescents and adults. Some have developed proficiency by getting extra training for ADHD, but currently, this is the exception, not the rule.

Does ADHD look pretty much the same at each age level or does it change as the person gets older?

ADHD-related impairments are determined based on the level of development of executive functions commonly demonstrated by most individuals of similar age. The infrastructure of the brain that supports executive functions develops very slowly and is not fully matured until late teens or early 20s. A person with ADHD is one whose executive functions are significantly underdeveloped or inconsistent relative to those of most others of comparable age. This involves different functions related to what is expected as one progresses from one age to the next.

Once adequate executive function has developed, does ADHD persist?

Natural developments in midlife and beyond can impair executive functioning. Also, as one gets older, normal development includes some processes of decline. The aging process alone tends to produce some impairments of executive functioning in persons not experiencing disease processes such as dementia. For example, some women experience in menopause some executive function impairments as their estrogen levels diminish. Recent research has shown that treatment with ADHD medications may help those women.

Also, both genders tend to experience some slowing of processing speed and diminution of working memory efficiency as an aspect of normal aging. Some older adults report that treatment with ADHD medication seems to alleviate these developmental impairments somewhat.

Is ADHD purely an American problem, or is it found elsewhere in the world?

When the same diagnostic criteria are utilized, ADHD is found in most developed and developing countries, especially where there are significant demands for literacy. Despite methodological differences and regional differences, a meta-analysis of 102 studies including 171,000 individuals found the prevalence of ADHD to be 5.29 percent among persons 18 years or younger and 2.8 to 4.4 in adults from regions all over the world.

Isn’t ADHD really a problem only during the school years? Does it have any significant negative impact on an individual’s adult life?

Long-term studies comparing sample groups of individuals with ADHD to matched groups without ADHD show that those with ADHD are less likely to complete high school, complete fewer years of post-high school education, are less likely to complete a college degree, are more likely to be employed in unskilled occupations, are more likely to have a substance use disorder, and are more likely to quit or be fired from a job. One population study found that individuals with ADHD also have elevated risk for attempted suicide and completed suicide Some with ADHD are very successful in adult life, but for many, ADHD-related impairments bring many continuing difficulties.

Can medication cure ADHD?

Medications used to treat ADHD cure nothing. They work more like eyeglasses or contact lenses that do not cure vision problems, but, if properly fitted, they can significantly improve vision during the time the person is wearing them. About 80 percent of those with ADHD find that carefully fine-tuned medication can improve their ADHD impairments significantly during those parts of the day when the medication is active. For some, improvement is huge; for others, substantial, but not huge, for some, it helps somewhat but not a lot; and for about 20 percent it does not work or it causes side effects that the person does not want to deal with.

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