What Is ADHD? (and What Is It Not?)
Our understanding of attention deficit has grown significantly over the last decade. Here, the director of the Yale Clinic for Attention and Related Disorders explains findings from ADHD research and how it impacts diagnostic criteria, treatment options, and future expectations for your family.
Reviewed on August 8, 2018
Findings from neuroscience, brain imaging, and clinical research have made the old understanding of ADHD as essentially a behavior disorder no longer tenable. It is being replaced by a new understanding of ADHD as a developmental impairment of the brain’s self-management system, its executive functions.
This new paradigm can provide a useful way to put together many of the not-yet-integrated pieces of research on this puzzling syndrome, which causes some children and adults to have great difficulty in focusing and managing many aspects of their daily life while being able to focus on other tasks well. This new understanding provides a useful way to more readily recognize, understand, assess, and treat this complex syndrome, which impacts about 9 percent of children and almost 5 percent of adults.
Here are 16 prevailing myths about ADHD, along with the latest facts, to update your thinking about the condition.
MYTH: Really Something New?
The new model of ADHD as developmentally impaired executive function is completely different from the older model of ADHD.
THE FACTS: The new model of ADHD differs in many ways from the earlier model of this disorder as essentially a cluster of behavior problems in young children. The new model is truly a paradigm shift for understanding this syndrome. It applies not only to children, but also to adolescents and adults. It focuses on a wide range of self-management functions linked to complex operations of the brain, and these are not limited to readily observable behaviors.
However, there are substantial and important points of overlap between the old and new models of ADHD. The new model is an extension and expansion of the old model. Most individuals who meet diagnostic criteria for the new model will also meet the criteria for the older model. The old model is no longer tenable, not because it identifies individuals with a different disorder, but because it does not adequately capture the breadth, complexity, and persistence of this syndrome.
MYTH: Not Always a Challenge
A person who has ADHD always has difficulty with executive functions, such as sustaining focus on a task and keeping several things in mind, regardless of what he is doing.
THE FACTS: Clinical data indicate that executive function impairments characteristic of ADHD are situationally-variable; each person with ADHD tends to have some specific activities or situations in which she has no difficulty in using executive functions that are significantly impaired for her in most other situations. Typically, these are activities in which the person with ADHD has a strong personal interest or about which he believes something very unpleasant will follow quickly if he does not take care of this task right now. Research findings indicate that intra-individual variability in performance from one context or time to another is the essence of ADHD. Multiple studies have shown that performance of persons with ADHD is highly sensitive to contextual factors — reward, nature of the task, and internal cognitive and physiological factors.
MYTH: Signs in Childhood
Anyone who has ADHD will show clear signs of it during early childhood and will continue to have difficulties with executive functions for the rest of his life.
THE FACTS: For decades ADHD, under various names, has been seen as essentially a disorder of childhood; DSM-V (Diagnostic and Statistical Manual of Mental Disorders-V) diagnostic criteria stipulates that at least some of the symptoms must be noticeable by age 12, changed from age 7 just a few years ago. More recent research has shown that many with ADHD function well during childhood and do not manifest any significant symptoms of ADHD until adolescence or later, when greater challenges to executive function are encountered. Over the past decade research has shown that impairing symptoms of ADHD often persist well into adulthood. However, longitudinal studies have also shown that some individuals with ADHD during childhood experience significant reductions in their ADHD impairments as they grow older.
MYTH: High IQ and Challenges
People with high IQ are not likely to have executive function impairments of ADHD because they can overcome such difficulties.
THE FACTS: Intelligence as measured by IQ tests has virtually no systematic relationship to the syndrome of executive function impairments described in the new model of ADHD. Studies have shown that even extremely high-IQ children and adults can suffer impairments of ADHD, which significantly impair their ability to deploy their strong cognitive skills consistently and effectively in many situations of daily life. Clinical observations indicate that high-IQ individuals with ADHD often face lengthy delays before they obtain a correct diagnosis and appropriate treatment. This is due largely to uninformed teachers, clinicians, and patients themselves, assuming that high IQ precludes ADHD.
MYTH: EFS and Adolescence
Executive function impairments of ADHD usually are outgrown when the person reaches her late teens or early twenties.
THE FACTS: Some children with ADHD gradually outgrow their ADHD-related impairments as they get into middle childhood or adolescence. For them, ADHD is a variety of developmental lags. Most often hyperactive and/or impulsive symptoms improve as the individual reaches adolescence, while the broad range of inattention symptoms persist and sometimes get worse. Often the most problematic period is during junior high, high school, and the first few years of college. That is the time when the individual faces the widest range of challenging activities without opportunity to escape from the ones in which they have little interest or ability. After that period, some with ADHD are fortunate enough to find a job and a life situation in which they can build on their strengths and work around their cognitive weaknesses.
MYTH: Mapping Deficits
Modern research methods have established that executive function impairments are localized mainly in the prefrontal cortex.
THE FACTS: Executive functions are complex and involve not only the prefrontal cortex, but also many other components of the brain. Individuals with ADHD have been shown to differ in the rate of maturation of specific areas of the cortex, in the thickness of the cortical tissue, in characteristics of the parietal and cerebellar regions, as well as in the basal ganglia, and in the white matter tracts that connect and provide critically important communication between various regions of the brain.
Recent research has also shown that those with ADHD tend to have different patterns in functional connectivity, patterns of oscillations that allow different regions of the brain to exchange information.
MYTH: A Brain Chemical Problem?
ADHD-related executive function impairments are due primarily to a “chemical imbalance” in the brain.
THE FACTS: The term “chemical imbalance in the brain” is often used to explain impairments of ADHD. This suggests that there are chemicals floating around in the cerebral spinal fluid that surrounds the brain that are not in correct proportions, as though there were too much salt in the soup. This assumption is wrong. Impairments of ADHD are not due to a global excess or lack of a specific chemical within or around the brain. The primary problem is related to chemicals manufactured, released, and then reloaded at the level of synapses, the trillions of infinitesimal junctions between certain networks of neurons that manage critical activities within the brain’s management system.
The brain is essentially a huge electrical system that has multiple subsystems that need to communicate with one another constantly to get anything done. This system operates on low-voltage electrical impulses that carry messages from one tiny neuron to another in fractions of a second. However, these neurons are not physically connected; there are gaps at each point of connection. To get from one neuron to another, an electrical message needs to jump the gap. Arrival of the electrical impulse causes tiny “micro-dots” of a neurotransmitter chemical to be released. This works like a spark plug to carry the message across the gap and further down the circuit.
Persons with ADHD tend not to release enough of these essential chemicals, or to release and reload them too quickly, before an adequate connection has been made. Medications used to treat ADHD help to improve this process.
MYTH: The ADHD Gene
Recent research has identified a gene that causes executive function problems in persons with ADHD.
THE FACTS: Despite extensive exploration of the genome and the high heritability rate of ADHD, no single gene or genes have been identified as a cause of the syndrome of impairments known as ADHD. Recent research has identified two different groupings that together are associated with, though not definitively causal of, ADHD. This combination of some common variant genes and a group of deletions or duplications of multiple rare variants offers some promise of further progress in the search for genetic factors contributing to ADHD. However, at this point, the complexity of the disorder is likely to be associated with multiple genes, each of which, in itself, has only a small effect upon development of ADHD.
MYTH: ODD and ADHD
Most children with ADHD also have behavior problems of Oppositional Defiant Disorder, which usually lead to the more severe behaviors of Conduct Disorder.
THE FACTS: Among children with ADHD, reported incidence of Oppositional Defiant Disorder (ODD) ranges from 40 percent to 70 percent. The higher rates are usually for persons with the combined type of ADHD rather than the inattentive type. This disorder is characterized by chronic problems with negativistic, disobedient, defiant and/or hostile behavior toward authority figures. It tends to involve difficulties with management of frustration, anger, and impulsive negative reactions when frustrated. Typically, ODD is apparent at about 12 years of age and persists for approximately six years and then gradually remits. More than 70 percent of children diagnosed with this disorder never go on to meet diagnostic criteria for Conduct Disorder, a diagnosis that reflects much more severe behavior problems.
MYTH: ADHD and Autism
An individual with an Autistic Spectrum Disorder should not be diagnosed with ADHD and vice versa. These are separate disorders that require different treatments.
THE FACTS: Research has demonstrated that many individuals with ADHD have significant traits related to Autistic Spectrum Disorders, and that many persons diagnosed with disorders on the Autistic Spectrum also meet diagnostic criteria for ADHD. Studies have also shown that ADHD medications can be helpful in alleviating ADHD impairments in individuals on the Autistic Spectrum. Moreover, ADHD medications can also help those on the Autistic Spectrum with ADHD to improve on some of their impairments in social interactions, social perspective-taking, and other related problematic characteristics.
MYTH: Meds and Brain Changes
There is no evidence that medications for ADHD improve executive function impairments or that any improvements last.
THE FACTS: There are three different types of evidence that demonstrate the effectiveness of specific medications for ADHD improving impaired executive functions.
First, imaging studies have shown that stimulants improve, and may normalize, the ability of individuals with ADHD to get activated for assigned tasks, to minimize distractibility while doing tasks, to improve functional connections between various regions of the brain involved in executive functions, to improve working memory performance, to reduce boredom during task performance, and, in some cases, to normalize some structural abnormalities in specific brain regions of those with ADHD.
Second, experiments comparing performance of children with ADHD with matched controls or when on placebo, in comparison to prescribed medication, have shown that when on appropriate medication, children with ADHD tend to minimize inappropriate classroom behavior and control their behavior more like typical children in their class.
Experiments have also shown that medication can help those with ADHD improve their speed and accuracy in solving arithmetic problems; increases their willingness to persist in trying to solve frustrating problems; improves their working memory; and increases their motivation to perform and execute more adequately a wide variety of tasks associated with executive functions. These results do not mean that all children on such medications display these results, but group data demonstrate statistically significant improvements. However, it should be noted that these results are found only during the time the medication is actually active in the person’s body.
Third, a large number of clinical trials comparing the effectiveness of ADHD medications versus placebo for alleviation of ADHD impairments in both children and adults have demonstrated that these medications, both stimulants and some non-stimulants, produce robust improvements in a large percentage of patients with ADHD. Most of these clinical trials have used DSM-IV diagnostic criteria for ADHD, but some have tested medications against the wider range of ADHD. Similar effectiveness results have been shown in symptoms from both the old and new models.
Despite the fact that the direct effects of medication do not last beyond the duration of the medication’s action each day, the improved functioning made possible by the medication has been shown to result in better school classroom and test performance, reduced rates of school dropout, increased rates of graduation, and other achievements that can have lasting effects. Medication may also help support a person’s adaptive performance while she awaits further brain development and enters into employment for which she is better suited, and/or improve her learning of concepts and skills she would otherwise be unlikely to master.
MYTH: Meds for Different Ages
The dose and timing of medications used to treat executive function impairment are quite similar for persons of similar age and body mass.
THE FACTS: Some medications can be appropriately prescribed in doses directly related to the patient’s age, size, or severity of symptoms, but this is not true for stimulants used to treat ADHD. Fine-tuning of dose and timing of stimulants for ADHD is important because the most effective dose depends on how sensitive the particular patient’s body is to that specific medication. Usually that needs to be determined by trial and error, starting with a very low dose and gradually increasing it until an effective dose is found, significant adverse effects occur, or the maximum recommended dose is reached. Some adolescents and adults need smaller doses than what is usually prescribed for young children, and some young children need larger doses than most of their peers.
MYTH: Preschoolers and Meds
It is quite risky to administer ADHD medications to preschool-aged children.
THE FACTS: While many children with ADHD do not show significant impairments until they begin elementary school, there are some preschoolers who manifest serious, and sometimes dangerous, behavior problems between the ages of three to six years. Research with children aged three to five-and-a-half years has shown that a majority of children in this age group with moderate to severe ADHD show significant improvement in their ADHD symptoms when treated with stimulant medication. With this younger age group, side effects are slightly more common than is usually seen in older children, though such effects were still minimal. In 2012 the American Academy of Pediatrics recommended that children aged four to five years old with significant ADHD impairments should be treated first with behavior therapy and then, if that is not effective within nine months, they should be treated with stimulant medication.
MYTH: A Lifelong Condition?
If a person with ADHD is hyperactive and impulsive during childhood, he is likely to continue that way into adulthood.
THE FACTS: Many individuals with ADHD never manifest excessive levels of hyperactivity or impulsivity in childhood or beyond. Among those with ADHD who are more “hyper” and impulsive in childhood, a substantial percentage outgrow those symptoms by middle childhood or early adolescence. However, symptoms of impairments in focusing and sustaining attention, organizing and getting started on tasks, managing emotions, using working memory, and so on tend to persist, and often become more problematic, as the individual with ADHD enters adolescence and adulthood.
MYTH: A Wide-Ranging Disorder
ADHD is just one of many kinds of psychiatric disorders.
THE FACTS: ADHD differs from many other disorders in that it cross-cuts other disorders. The executive function impairments that constitute ADHD underlie many other disorders as well. Many learning and psychiatric disorders could be compared to problems with a specific computer software package that, when not working well, interferes just with writing text or doing bookkeeping. In this new model, ADHD might be compared instead to a problem in the operating system of the computer that is likely to interfere with the effective operation of a variety of different programs.
MYTH: Emotional Connection
Emotions are not involved in executive functions associated with ADHD.
THE FACTS: Although earlier research on ADHD gave little attention to the role of emotion in this disorder, more recent research has highlighted its importance. Some research has focused solely on the problems in regulating expression of their emotions without sufficient inhibition or modulation. However, research has also demonstrated that a chronic deficit in emotions that comprise motivation is an important aspect of impairments for most individuals with ADHD. Studies have shown that this is related to measurable differences in the operation of the reward system within the brains of those with ADHD. Those with ADHD tend to have abnormalities in the anticipatory dopamine cell firing in the reward system; this makes it difficult for them to arouse and sustain motivation for activities that do not provide immediate and continuing reinforcement.
Copyright 2013, from A New Understanding of ADHD in Children and Adults by Thomas E. Brown, Ph.D. Reproduced with permission of Taylor and Francis Group, LLC, a division of Informa plc.