Adult attention deficit hyperactivity disorder: Underdiagnosed, undertreated

They may be the "eccentrics" whose behavior seem unconventional, or the "terrible-tempered" who are painfully bewildering, or the "explosive types" with whom reasoning is difficult. They may be victims of a disorder that is not for children only--

William Collins is 35 years old. He has been married and divorced three times. He has difficulty keeping a job. Minor things irritate him; he loses his temper and impulsively makes remarks that get him into trouble. Such constant, irritability has cost him 20 jobs and three marriages. At times he has been so angry that he stalks his wife, and whenever he loses his temper with his boss, he gets fired. The excuse he tells people is that he became bored with the job and quit. None of his jobs has ever amounted to much anyhow because he has trouble concentrating on work. People constantly remind him to pay attention because he forgets easily. Because of this he did poorly in school and hated every minute of it. His teachers thought he was either "slow" or "lazy" or "unmotivated," and they all thought his major problem was "poor self-esteem." As a teenager he found himself drinking to excess, and the only time he ever felt "normal" was when a friend gave him some "speed" (amphetamines).

Bill blamed his problems on his parents. His father was chronically unemployed, alcoholic, and his mother was always depressed and suffered many anxiety attacks. The therapist Bill consulted after his second divorce reinforced the tendency to blame his parents by claiming his problem came from a dysfunctional family and that he could never learn adequate coping skills. At one point the therapist wondered whether his anger wasn't the result of sexual abuse so early in life that he could not remember. However, despite .a year in therapy, his behavior did not change. Bill came to believe that nothing would ever be better for him.

Bill's problems are not the result of dysfunctional family or sexual abuse. He has a genetic disorder that caused a chemical imbalance in his brain that interferes with how his brain works. He has adult attention deficit disorder with hyperactivity (ADHD). Ironically, it is a very treatable disorder. But because it was never diagnosed, Bill in essence lost the first third of his life. Bill is not alone.

ADHD in Children
Attention deficit hyperactivity disorder, commonly known as ADHD, is the most common behavioral disorder of childhood. It occurs in 4 to 8 percent of boys and 2 to 5 percent of girls. It was first described in the early part of this century and was initially thought to be the result of some type of brain damage, thus the name minimal brain damage, or MBD. By the 1960s, it had become clear that only a minority of children had any evidence of brain damage and the name was changed to "hyperkinetic syndrome" or "hyperactivity."

In 1980, with the publication of the third edition of the psychiatric bible, the Diagnostic and Statistical Journal of Mental Disorders (DSM-III), the name was changed again to Attention Deficit Disorder, or ADD. This correctly emphasized that the major problem distinguishing these children from their peers was an inability to pay attention, especially in a crowded, noisy classroom. In 1987, when the DSM-III was revised, the name was changed again to Attention Deficit Hyperactivity Disorder-ADHD.

It is a common misperception that children with ADHD always grow out of it by the time they are adults. This is incorrect. Approximately 50 percent of the time the symptoms persist into adulthood. However, the diagnosis is often missed for three reasons:

First, the symptoms of motor hyperactivity tend to disappear as children grow older. As a result, affected adults appear more normal, in that they are not constantly running around like most children with ADHD. However, they are still restless inside and have great difficulty sitting still for very long.

Second, adults are no longer in school and it is in school that ADHD subjects have the most difficulty. For example, if a person with ADHD, who was unable to sit still and concentrate in class, takes a job outside as a construction worker or a salesman, the restless need to be in constant activity may be perceived as an advantage rather than a disadvantage.

Third, although the adult form of ADHD was well described in the 1980 DSM III unfortunately for affected individuals, this diagnosis was essentially left @ut of the 1987 version, disenfranchising adults with the disorder. The DSM III criteria are shown:

Diagnosis of Adult Attention Deficit Hyperactivity Disorder
Meets criteria for ADHD as a child.
Signs of hyperactivity are no longer present, but other signs of the illness have persisted to the present without periods of remission, as evidenced by signs of both attentional deficits and impulsivity (e.g. difficulty organizing work and completing tasks, difficulty concentrating, being easily distracted, making sudden decisions without thought of the consequences.)
Symptoms of inattention and impulsivity result in some impairment in social or occupational functioning.
Not due to other major mental disorders.
Reprinted with permission from the third edition of The Diagnostic and Statistician Manual of Mental Disorders (DSM III).

Symptoms of Adult ADHD
The features in the box represent the official diagnostic criteria, but in practice there are many more symptoms of adult ADHD. They include the following, in alphabetical order. Not all subjects have these symptoms; they are just much more common in adult ADHD.

Always late, poor sense of time
Bored easily
Cannot keep checkbook balanced
Chronic fatigue
Compulsive and impulsive spending
Difficulty with authority figures
Failed to finish high school
"Foot-in-mouth" disease -- says inappropriate things before
Forgets things
History of multiple jobs
Interrupts others
Likes risky sports
Loses train of thought
Low frustration tolerance
Low self-esteem
May have been arrested or spent some time in jail
May verbally or physically abuse spouse or children
Mood swings
Muscle tics
Poor concentration
Poor in math in school
Poor short-term memory
Poor with spatial concepts
Preference for jobs involving verbal skills, such as salesman
Preference with jobs involving working with the hands
Preference for self-employment
Problems with alcohol and drug abuse
Racing thoughts
Rage attacks
Reading problems (dyslexia)
Restless -- cannot sit still, cracks knuckles, bites nails,
jiggles feet
Short or hot temper
Talk excessively
Unable to finish high school or college
Unstable personal relationships
Vocal tics
If there were space, a hundred vignettes could be presented showing how this combination of symptoms can cause chaos in the lives of the affected. I leave those life histories, all variations on Bill's story, to the imagination of the reader. Everyone may have a few of these symptoms. It is the clustering of many together that define the individual with adult ADHD. One may ask how one person or one disorder could have so many symptoms. The answer is that the genes causing ADHD affect the level of critical brain chemicals (dopamine, serotonin and norepinephrine), and these chemicals regulate or modulate the function of many areas of the brain. Thus the multitude of symptoms.

The Genetics of ADHD
Although many causes of ADHD have been proposed, in my experience the vast majority of cases are genetic. Detailed pedigrees or family histories of ADHD patients almost always uncover multiple relatives who either have ADHD themselves or have one or more relatives with addictive, mood, anxiety, or learning disorders. Specifically, these include alcoholism, drug abuse, depression, manic-depressive disorders, obsessive-compulsive behaviors, dyslexia, compulsive eating with obesity, panic attacks, phobias and others. A typical pedigree of an adult ADHD patient is shown in Figure 1. As in this family, most show evidence of behavioral disorders on both the mother's and father's side of the family. This leads me to believe that most ADHD patients have received an abnormal gene from both parents and thus have a double dose themselves. Adult ADHD is so common because these genes are very common. We have estimated that up to 20 percent of the population carry a single dose of these genes.

Tourette Syndrome and ADHD
Tourette syndrome (TS) is a genetic disorder characterized by the presence of muscle tics (eyeblinking, facial grimacing, shoulder shrugging, arm jerking) and vocal tics (throat clearing, grunting, spitting, squeaking, snorting and others). ADHD is very common in patients with TS. Fifty to 80 percent of TS patients who seek medical care have ADHD. In addition, TS patients have the same spectrum of other behaviors that are common in people with ADHD, such as obsessive-compulsive behaviors, mood swings, anxiety, short temper, and learning disorders. The two disorders are so similar that I suspect they are caused by the same gene or genes. TS can be thought of as ADHD with tics. Up to half of individuals with adult ADHD had chronic tics as a child, or still have tics, or have other family members with chronic tics.

A Defect in the Frontal Lobes
While it is unlikely that a single area of the brain is involved in ADHD, some areas appear to be much more severely affected than others. This is particularly true of the frontal lobes. Psychological tests show that most ADHD patients have defective functioning of the frontal lobes. PET scans, which examine the function of the frontal lobes with radioactive compounds, have shown that in adults with ADHD the frontal lobes are under-utilized. The frontal lobes are required for paying attention, motivation, and formulating a thoughtful response to events that are going on in the environment. It thus comes as no surprise that when the frontal lobes are not functioning properly, affected individuals tend to have problems with paying attention, motivation, and impulsivity.

Abdormal Dopamine Receptor Genes in ADHD
The genes that cause ADHD have not been discovered but one gene that at least contributes to the problem has been identified. This is the dopamine D2 receptor gene. Dopamine is a D2 receptor gene. Dopamine is an important brain chemical or neurotransmitter that controls motor activity. Receptors are proteins on the surface of nerve cells that recognize and bind to neurotransmitters, much like a lock and a key. Without receptors, the neurotransmitters would be useless.

When there is a dopamine deficiency, as in Parkinson's disease, patients cannot move. Oliver Sacks' book and movie, Awakenings, described the frozen, statue-like inactivity of Parkinson's disease patients. By contrast, when there is too much dopamine, or when the dopamine receptors in specific parts of the brain are hypersensitive to dopamine, there is too much movement, i.e., hyperactivity. In the process of studying the possible role of variants of the dopamine D[sub2] receptor in alcoholism and drug abuse, we also examined a number of patients with Tourette syndrome and ADHD. This showed that specific genetic variants of the dopamine D2 receptor gene are almost twice as common in TS and ADHD patients (45 percent) than in controls (25 percent). We suspect that the dopamine D2 receptor acts as a modifying gene, affecting the severity of the TS and ADHD symptoms.

Treatment of ADHD
Even though it is predominantly caused by defective genes, adult ADHD is a very treatable disorder. The most effective medications are the tricyclical antidepressants such as Tofranil (imipramine) and Norpramin (despiramine); dopaminergic antidepressants such as Wellbutrin (bupropion); and stimulant medications such as Ritalin (methylphenidate) and Dexedrine (dextroamphetamine). The fact that all of these medications help to supply dopamine to the brain is consistent with the theory that ADHD is in part due to a deficiency of dopamine in one part of the brain leading to hypersensitivity to dopamine in other parts of the brain.

Of the above medications, Ritalin and Dexedrine are often the only ones that are effective. These come with a major problem. Since these drugs are also controlled substances, individuals with adult ADHD often have great difficulty finding a physician willing to treat them. This is true for the following reasons: (1) some physicians mistakenly think that ADHD disappears in the teen years and that the adult ADHD does not exist, (2) they think that anyone actively seeking treatment with Ritalin or Dexedrine is just a drug addict looking for a high, (3) the physicians may be afraid to prescribe Ritalin or Dexedrine for fear that they may lose their license, (4) or the physician thinks that these drugs no longer work in adults.

All of these misconceptions are wrong. Adult ADHD not only exists but is common. Stimulant medications do not cause euphoria in subjects with ADHD; they tend to calm them down and allow them to focus and be less explosive and irritable. In my experience and that of others, individuals with ADHD who are properly treated are much less likely to become drug addicts than those who are untreated. This suggests that many addicts have been using street drugs in a vain attempt to treat themselves. A physician should have no fear of prescribing stimulant medications for individuals properly documented and diagnosed by DSM-III criteria as having ADHD. Finally the medications are just as effective in the treatment of ADHD in adults as they are in children.

In conclusion, adult ADHD is a common disorder characterized by difficulty organizing work and completing tasks, difficulty concentrating, being easily distracted, making sudden decisions without thought of the consequences, and other symptoms. Although ADHD is underdiagnosed, it is effectively treated by the same medications used to treat childhood ADHD. Genetic factors play a major role in causing both childhood and adult ADHD. The identification of these genes should lead to genetic tests allowing a more accurate and rapid diagnosis. This should allow physicians to treat ADHD with greater precision and confidence.


DIAGRAM: Figure 1. Family pedigree of a patient with adult ADHD (arrow), showing the high frequency of alcoholism, drug addiction, ADHD, and other behavioral disorders on both parents' side of the family.


Comings D.E.: Tourette Syndrome and Human Behavior, Hope Press,
P.O. Box 188, Duarte, CA 91009, 828 pp. 642 diagrams. Cloth
$49.95. Paperback $39.95.

This book is written for a general audience and covers in much
more detail all of the subjects discussed above, plus many
additional aspects of human behavior. To order call

Comings, D.E., et al: The Dopamine D2 Receptor Locus as a
Modifying Gene in Neuropsychiatric Disorders. JAMA. 266:
1793-1800, (Oct. 2), 1991.
This more technical paper describes the role of the dopamine D2 receptor genes to ADHD and other disorders. For a free copy, write to Dr. Comings,Department of Medical Genetics, City of Hope Medical Center; Duarte, CA 91010


By E. Comings, M.D.

Department of Medical Genetics, City of Hope National Medical Center, Duarte, California

The criteria for the diagnosis of childhood ADHD are shown in the box entitled Diagnosis of Childhood ADHD. These are from the 1987 version, DSM-III-R.

Diagnosis of Childhood ADHD
Must have 8 or more of the following:

Often "fidgets with hands or feet ore squirms in seat.
Has difficulty remaining seated when required to do so.
Is easily distracted by extraneous stimuli.
Has difficulty awaiting turn in games or group situations.
Often blurts out answers to questions before they have been completed.
Has difficulty following through on instructions from others and fails to finish chores.
Has difficulty sustaining attention in tasks or play activities.
Often shifts from one uncompleted activity to another.
Has difficulty playing quietly.
Often talks excessively.
Often interrupts or intrudes on others or butts into other children's games.
Often does not seem to listen to what is being said to him or her.
Often loses things necessary for tasks or activities at school or at home. Reprinted by permission from the Third Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM III)
Reprinted by permission from the Third Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM III)

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