As it has become more widely recognized in recent years, Attention-Deficit/Hyperactivity Disorder (ADHD or ADD) has precipitated a great deal of controversy. Some claim that it is over-diagnosed, others that it is under-diagnosed. Some authorities feel that the drugs used to treat it are prescribed too readily, or question if the medications are safe. The exact causes of the disorder, the best way to diagnose the disorder, and the reasons the medications work in treating the disorder are still under investigation.
Three subtypes of ADHD exist. The Hyperactive-Impulse Type describes a teen who seems to have too much excess energy and who cannot sit still, who frequently interrupts others or makes decisions without thinking. This person often doesn't realize what is socially appropriate in a given situation. The Inattentive Type describes a person who has trouble with organization, is easily distracted, and is often sluggish. The Combined Type describes an adolescent who meets criteria for both of the other types. In order to be diagnosed with ADHD, these characteristics must cause problems for the person in two areas—usually both at school and at home.
The exact cause of ADHD is unknown; multiple factors likely contribute, with different causes for the different subtypes of ADHD. Contrary to widespread belief, sugar consumption is not an aggravating agent. Genetics certainly plays a role—the disorder tends to run in families, and in sets of twins in which one suffers from the disorder, there is a ninety percent chance that the other one will as well. The underlying problem appears to be a chemical imbalance in the brain. The nervous system uses several different chemicals that act as “neurotransmitters.” They transmit signals from one neuron to another in the brain, part of an electrical-chemical chain of events that governs all of the functioning, both conscious and unconscious, of the body. One candidate likely to be a culprit in ADHD is dopamine. Researchers have found variations in the gene encoding one of the receptors in the brain that is influenced by dopamine; these variations correlate with a person's likelihood to develop ADHD. Serotonin is another molecule that may be involved. Comparisons of brain images by MRI or PET scans in people with and without ADHD have also suggested structural differences, some of which may correspond to areas in which these neurotransmitters are active, and differences in the way sugars are used by the brain. All of these are clues to finding medications that work in restoring the correct chemical balance in the brains of patients with ADHD, so that they can focus their attention on one thing at a time, or feel less restless.
Often, multiple contributing factors influence the development of a disorder that has a genetic basis; that is, there is a genetic predisposition to the disease, but it may not show up in everyone who has those genes—other environmental factors also need to be present to trigger it. This is possibly the case with ADHD as well. Patients living in disruptive home environments may be more susceptible to manifesting the underlying ADHD.
Adolescence is a time of many physical, emotional and psychological changes; teens develop self-identity and are faced with myriad pressures. This presents new challenges for coping with ADHD. Approximately seventy-five percent of cases of ADHD persist into adolescence. Those with Inattentive type and severe Hyperactive-Impulse type may require medication through high school and college, while those with less severe Hyperactive type often require medication only until early adolescence. Some, however, will require medication into adulthood, although the character of the symptoms may change over the course of development. Instead of being physically restless, for example, adolescents might feel mentally restless instead.
Starting middle school or high school may also precipitate a diagnosis of ADHD. This is particularly true for students with the Inattentive type, often girls, who have previously been able to function well enough in school but now are unable to keep up with the extra demands and start to experience a decline in schoolwork and grades.
Adolescents may also become more self-conscious and aware of being set apart as different because they need to take a medication or require extra assistance in school. Some teens diagnosed and treated for ADHD also have problems with their self-esteem.
ADHD is associated with risk factors that become increasingly important during the teen years. Impulsive behavior may manifest as reckless driving. Eating disorders that occur in adolescence may be more threatening in combination with appetite-suppressing stimulant treatment for ADHD. Adolescents are often pressured to experiment with illegal substances, and teens with ADHD have been found to begin experimenting with tobacco, alcohol and drugs at an earlier age than others. Adolescents may also face pressure from their peers to give or sell them their ADHD medications, or the patients themselves may abuse the medications.
Who is likely to develop ADHD?
ADHD is a chronic condition that affects children, adolescents, and adults, but is most commonly diagnosed in children. In fact, one of the criteria for diagnosis is that some of the symptoms be present before age seven. Four to twelve percent of school-age children suffer from ADHD. In school-age children, as many as ninety percent of these individuals are boys. The gender ratio is slightly less lopsided in adolescents and adults. Part of the reason for this may be that boys are more likely to have the Hyperactive-Impulse type, and they thus get noticed earlier on. People with the Inattentive type are more likely to be female and to get diagnosed when they are older and begin having academic problems. People with the combined type often experience problems in more areas and may have greater difficulties with behavior and aggression.
Children may be diagnosed with ADHD when they are as young as four years old. In looking back, however, parents can often remember signs of hyperactivity earlier on—babies who were particularly active during the last three months of pregnancy, infants who were very fussy and demanding, or toddlers who began running almost as soon as they learned to walk.
People with ADHD are not any more or less intelligent than people who do not have the disorder—both populations have the same range of IQ scores.
What are the symptoms of ADHD?
A teen with ADHD may have poor self-esteem and difficulty in relationships with his peers, teachers, and parents. He may make careless mistakes, seem not to listen, be easily distracted and forgetful, and have problems with organization. He may have difficulty staying focused and might avoid activities that require sustained attention. He may not follow through on assignments. A teen with the hyperactivity-impulsivity type of ADHD may feel restless and fidget constantly. He may have difficulty waiting his turn, instead interrupting others or blurting out answers. He may talk excessively or seem to have unlimited energy. The symptoms of ADHD are present at least six months or longer and interfere with the teen’s life in multiple areas. Some teens who have been able to cope with academics in middle school are confronted with these issues in high school. It is not unusual for high school or even college students to be diagnosed with ADD.
How is ADHD evaluated?
Despite the many clues to possible causes of ADHD, there is unfortunately no definitive test to diagnose the disorder. Instead, clinicians often use standardized questionnaires—given to patients, their parents, and their teachers—to find out whether various behaviors are present and interfering with school and home life.
It is also important to determine that the symptoms or complaints are caused by ADHD and not by another disorder. For example, a child with hearing loss may also appear to be inattentive and may have similar problems with schoolwork. Some medications, such as anticonvulsants, decongestants, bronchodilators, or steroids, may have side effects that mimic ADHD behavior. Other illnesses, such as lead poisoning, epilepsy, thyroid disease or encephalopathy, are also causes to consider. Mood disorder, anxiety, and behavior and learning disorders may all be mistaken for ADHD.
Although ADHD must be differentiated from other possible causes of the symptoms, it is also important to realize that ADHD is often present in conjunction with other disorders. Between six and twenty percent of people with ADHD will also have a learning disorder. Fifteen to twenty percent of people with ADHD will also have a mood disorder. Oppositional defiant disorder and conduct disorder, two disruptive behavior disorders, are present in forty to seventy percent of people with ADHD. Thyroid disorder, obsessive-compulsive disorder and Tourette's syndrome, a disorder characterized by vocal outbursts and motor tics, are other commonly associated phenomena. The presence of these other conditions can make the diagnosis of ADHD more difficult, and it may make managing ADHD more complicated for the patient and the patient's family.
How is ADHD treated?
Luckily, several effective medications are helpful for the treatment of ADHD. Stimulants have a positive effect in approximately eighty percent of patients with ADHD. These include methylphenidate, dextroamphetamine and mixtures of amphetamine salts; they come in oral preparations that aim for a short, intermediate or long duration of action. In 2006, a medication patch for the treatment of ADHD was under consideration by the Food and Drug Administration. ADD medications affect the transmission and breakdown of dopamine, one of the chemical messengers in the brain. They have been shown to improve attention; decrease motor activity, impulsivity, and aggression; and improve academic function and social interactions. Antidepressants such as tricyclics or buproprion are often effective, especially in cases in which there is a coexistent mood disorder. Behavioral therapy is also sometimes used in addition to or instead of medications. Special diets have not been validated as helpful in treating ADHD.
Stimulants may cause insomnia, appetite suppression and resultant weight loss, irritability, or tics. Other problems may include “rebound” effects in the afternoon after the morning dose wears off. Most of these adverse effects are temporary, disappearing in one to six months, or can be avoided by adjusting the dosing schedule. Some of the medications should be avoided in patients with hypertension or cardiac disease.
Overdose of stimulants can cause confusion, sweating, vomiting, muscle spasms, and respiratory problems. There has been no evidence of any danger of developing dependence on or addiction to these medications. They may be abused, however, and are sometimes crushed and inhaled for a euphoric high. Adolescents treated for ADHD should be followed periodically by a clinician to monitor medication side effects and achievement of treatment goals.
In addition to medications, patients may benefit from special programs in school. Some patients will be eligible for special education or for special accommodations, such as extra time to take tests. Teens and their families should work in cooperation with their teachers to develop organizational methods for keeping track of assignments, completing homework and establishing target outcomes. In addition, behavioral techniques such as positive reinforcement and time-out may be beneficial.
How is ADHD prevented?
ADHD is due to a chemical imbalance in the brain. It is not preventable.
Related topics:
Academics, alcohol, amphetamines, chronic illness, counseling, genetic disease, risk-taking, self-esteem, substance abuse
