Some patients are able to control their symptoms over time, without the use of medication. Certain social critics are skeptical that the diagnosis denotes a genuine impairment or disability. The symptoms of ADHD are not as profoundly different from normal behavior as is often seen with other mental disorders. Still, ADHD has been shown to be impairing in life functioning in several settings and many negative life outcomes are associated with ADHD.

Definitions and Terminology of ADHD

ADHD is a developmental disorder that largely is neurological in nature. The term developmental means that certain traits such as impulse control significantly lag in development when compared to the general population. Some researchers have suggested that the degree of lag mirrors the degree of severity of the disorder. This developmental lag has been estimated to range between 30-40 percent in comparison to their peers; consequently these delayed attributes are considered an impairment. ADHD has also been classified as a behavioral disorder and a neurological disorder or combinations of these classifications such as neurobehavioural or neurodevelopmental disorders. These compounded terms are now more frequently used in the field to describe the disorder.

Note: The behavioral classification for ADHD is not completely accurate in that those with Predominately Inattentive ADHD often display little or no overt behaviors.

Diagnosis

According to the Diagnostic and Statistical Manual IV-Text Revision (DSM-IV-TR), the following criteria must be met for a person to be diagnosed with Attention-Deficit / Hyperactivity Disorder.

 

I. Either A or B:

 

A. Six or more of the following symptoms of inattention have been present for at least 6 months to a point that is disruptive and inappropriate for developmental level:

Inattention

• 1. Often does not give close attention to details or makes careless mistakes in schoolwork, work, or other activities.

• 2. Often has trouble keeping attention on tasks or play activities.

• 3. Often does not seem to listen when spoken to directly.

• 4. Often does not follow instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions).

• 5. Often has trouble organizing activities.

• 6. Often avoids, dislikes, or doesn't want to do things that take a lot of mental effort for a long period of time (such as schoolwork or homework).

• 7. Often loses things needed for tasks and activities (e.g. toys, school assignments, pencils, books, or tools).

• 8. Is often easily distracted.

• 9. Is often forgetful in daily activities.

B. Six or more of the following symptoms of hyperactivity-impulsivity have been present for at least 6 months to an extent that is disruptive and inappropriate for developmental level:

Hyperactivity

• 1. Often fidgets with hands or feet or squirms in seat.

• 2. Often gets up from seat when remaining in seat is expected.

• 3. Often runs about or climbs when and where it is not appropriate (adolescents or adults may feel very restless).

• 4. Often has trouble playing or enjoying leisure activities quietly.

• 5. Is often "on the go" or often acts as if "driven by a motor".

• 6. Often talks excessively.

Impulsivity

• 1. Often blurts out answers before questions have been finished.

• 2. Often has trouble waiting one's turn.

• 3. Often interrupts or intrudes on others (e.g., butts into conversations or games).

II. Some symptoms that cause impairment were present before age 7 years.

III. Some impairment from the symptoms is present in two or more settings (e.g. at school/work and at home).

IV. There must be clear evidence of significant impairment in social, school, or work functioning.

V. The symptoms do not happen only during the course of a Pervasive Developmental Disorder, Schizophrenia, or other Psychotic Disorder. The symptoms are not better accounted for by another mental disorder (e.g. Mood Disorder, Anxiety Disorder, Dissociative Disorder, or a Personality Disorder).

 

Based on these criteria, three types of ADHD are identified:

• 1. ADHD, Combined Type: if both criteria 1A and 1B are met for the past 6 months

• 2. ADHD, Predominantly Inattentive Type: if criterion 1A is met but criterion 1B is not met for the past six months

• 3. ADHD, Predominantly Hyperactive-Impulsive Type: if Criterion 1B is met but Criterion 1A is not met for the past six months.

ICD

In the tenth edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) the symptoms of ADHD are given the name "Hyperkinetic disorders". When a conduct disorder (as defined by ICD-10,^[10]) is present, the condition is referred to as "Hyperkinetic conduct disorder". Otherwise the disorder is classified as "Disturbance of Activity and Attention", "Other Hyperkinetic Disorders" or "Hyperkinetic Disorders, Unspecified". The latter is sometimes referred to as, "Hyperkinetic Syndrome".^[10] Because the editors of the ICD believe that the inability to pay attention constitutes a separate disorder, a person must be hyperactive in order to be diagnosed with a Hyperkinetic disorder.

 

The American Academy of Pediatrics Clinical Practice Guideline for children with ADHD emphasizes that a reliable diagnosis is dependent upon the fulfillment of three criteria:^[11]

• The use of explicit criteria for the diagnosis using the DSM-IV-TR.

• The importance of obtaining information about the child’s symptoms in more than one setting.

• The search for coexisting conditions that may make the diagnosis more difficult or complicate treatment planning.

The first criteria can be satisfied by using an ADHD-specific instrument such as the Conners' Rating Scale^[12][13] . The second criteria is best fulfilled by examining the individual's history. This history can be obtained from parents and teachers, or a patient's memory.^[14] The requirement that symptoms be present in more than one setting is very important because the problem may not be with the child, but instead with teachers or parents who are too demanding. The use of intelligence and psychological testing (to satisfy the third criteria) is essential in order to find or rule out other factors that might be causing or complicating the problems experienced by the patient.^[15]

 

The Centers for Disease Control and Prevention (CDC) state that a diagnosis of ADHD should only be made by trained health care providers, as many of the symptoms may also be part of other conditions, such as bodily illness or other physiological disorders, such as hyperthyroidism. It is not uncommon that physically and mentally nonpathological individuals exhibit at least some of the symptoms from time to time. Severity and pervasiveness of the symptoms leading to prominent functional impairment across different settings (school, work, social relationships) are major factors in a positive diagnosis.

 

Adults often continue to be impaired by ADHD. Adults with ADHD are diagnosed under the same criteria, including the stipulation that their symptoms must have been present prior to the age of seven.^[16] Adults face some of their greatest challenges in the areas of self-control and self-motivation, as well as executive functioning, usually having more symptoms of inattention and fewer of hyperactivity or impulsiveness than children do.^[17]

 

Common comorbid conditions are Oppositional Defiance Disorder (ODD). About 20% to 25% of children with ADHD meet criteria for a learning disorder.^[18] Learning disorders are more common when there are innattention symptoms.^[19]

 

Causes

 

PET scans of glucose metabolism in the brains of a normal adult (left) compared to an adult diagnosed with ADHD.[20]

The exact cause of ADHD remains unknown. Research suggests that ADHD arises from a combination of various genes, many of which affect dopamine transporters.[21] Suspect genes include the 10-repeat allele of the DAT1 gene,[22] the 7-repeat allele of the DRD4 gene,[22] and the dopamine beta hydroxylase gene (DBH TaqI).[23] Additionally, SPECT scans found people with ADHD to have reduced blood circulation,[24] and a significantly higher concentration of dopamine transporters in the striatum which is in charge of planning ahead.[25]   The exact cause of ADHD remains unknown. Research suggests that ADHD arises from a combination of various genes, many of which affect dopamine transporters.[21] Suspect genes include the 10-repeat allele of the DAT1 gene,[22] the 7-repeat allele of the DRD4 gene,[22] and the dopamine beta hydroxylase gene (DBH TaqI).[23] Additionally, SPECT scans found people with ADHD to have reduced blood circulation,[24] and a significantly higher concentration of dopamine transporters in the striatum which is in charge of planning ahead.[25]

 

A new study by the U.S. Department of Energy’s Brookhaven National Laboratory in collaboration with Mount Sinai School of Medicine in New York suggest that it is not the dopamine transporter levels that indicate ADHD, but the brain's ability to produce dopamine itself. The study was done by injecting 20 ADHD subjects and 25 control subjects with a radiotracer that attaches itself to dopamine transporters. The study found that it was not the transporter levels that indicated ADHD, but the dopamine itself. ADHD subjects showed lower levels of dopamine across the board. They speculated that since ADHD subjects had lower levels of dopamine to begin with, the number of transporters in the brain was not the telling factor.

 

An early PET scan study found that global cerebral glucose metabolism was 8.1% lower in medication-naive adults who had been diagnosed as ADHD while children. The image on the left illustrates glucose metabolism in the brain of an 'normal' adult while doing an assigned auditory attention task; the image on the right illustrates the areas of activity of the brain of an adult who had been diagnosed with ADHD as a child when given that same task; these are not pictures of individual brains, which would contain substantial overlap, these are images constructed to illustrate group-level differences. Additionally, the regions with the greatest deficit of activity in the ADHD patients (relative to the controls) included the premotor cortex and the superior prefrontal cortex.^[20] These findings strongly imply that lowered activity in specific regions of the brain, rather than a broad global deficit, is involved in ADHD symptoms. However, whether these differences prove ADHD is biological or merely represent differences in behavior when given an assigned task remains open to debate.

 

The estimated contribution of non genetic factors to the contribution of all cases of ADHD is 20 percent. The few environmental factors implicated fall in the realm of biohazards and include alcohol, tobacco smoke, and lead poisoning. Complications during pregnancy and birth—including premature birth—might also play a role. It has been observed that women who smoke while pregnant are more likely to have children with ADHD.^[26] This could be related to the fact than nicotine is known to cause hypoxia (lack of oxygen) in utero, but it could also be that ADHD women have more probabilities to smoke both in general and during pregnancy, being more likely to have children with ADHD due to genetic factors Head injuries can cause a person to present ADHD-like symptoms,^[27] possibly because of damage done to the patient's frontal lobes. Because this kind of symptoms can be attributable to brain damage, the earliest designation for ADHD was "Minimal Brain Damage".^[28]

 

There is no compelling evidence that social factors alone can create ADHD. Many researchers believe that attachments and relationships with caregivers and other features of a child's environment have profound effects on attentional and self-regulatory capacities. It is noteworthy that a study of foster children found that an inordinate number of them had symptoms closely resembling ADHD.^[29] An editorial in a special edition of Clinical Psychology in 2004 stated that "our impression from spending time with young people, their families and indeed colleagues from other disciplines is that a medical diagnosis and medication is not enough. In our clinical experience, without exception, we are finding that the same conduct typically labelled ADHD is shown by children in the context of violence and abuse, impaired parental attachments and other experiences of emotional trauma."^[30]

 

Despite the lack of evidence that nutrition can cause ADHD a moderate to severe protein deficiency, can cause symptoms consistent with ADHD.^[31][32] Studies have found metabolic differences in children with ADHD which may contribute to certain ADHD-like symptoms. In 1990 the English chemist, Neil Ward,^[33] showed that children with ADHD lose zinc when exposed to the food dye tartrazine. Some studies suggest that a lack of omega-3 fatty acids has been associated with certain ADHD symptoms.^[34] People with ADHD were found to have significantly lower plasma phospholipids and erythrocytes omega-3 fatty acids. Their intake of saturated fat was found to be 30% higher than in controls, while the intake of many other nutrients was not different.^[35]Mousain-Bosc and colleagues^[36] showed, in 2006, that children with ADHD (n = 46) had significantly lower red blood cell magnesium levels than controls (n = 30). Intervention with magnesium and vitamin B6 (pyridoxine) reduced hyperactivity, hyperemotivity/aggressiveness and improved school attention.

 

Treatment

There are many options available to treat people diagnosed with ADHD. The options with the greatest scientific support include: theraputic stimulants See Also: List of prescription medications for ADHD, and behavior modification. The results of a large randomized controlled trial^[37][38] suggested that medication alone is superior to behavioral therapy alone, but that the combination of behavioral therapy and medication has a small additional benefit over medication alone if the subjects had a comorbid disorder like anxiety that responds to therapy. Behaviour therapy made no difference to those subjects who had ADHD only.

 

The most frequently prescribed medications for ADHD are stimulants, which work by stimulating the areas of the brain responsible for focus, attention, and impulse control. The use of stimulants to treat a syndrome often characterized by hyperactivity is sometimes referred to as a paradoxical effect. But there is no real paradox in that stimulants activate brain inhibitory and self-organizing mechanisms permitting the individual to have greater self-regulation. Frequently prescribed stimulants are Methylphenidate (better known by the brand names Ritalin and Concerta), Amphetamines (Adderall) and dextroamphetamines (Dexedrine). A fourth stimulant, Modafinil (Provigil) is commonly prescribed off-label and is not approved for ADHD. A fifth stimulant, Cylert was used until the late 1980s when it was discovered that this medication could cause liver damage. In March 2005, the makers of Cylert announced that it would discontinue the medication's production.

 

It is no longer available in the United States. A sixth stimulant, Amineptine (Survector), is an atypical Tricyclic anti-Depressant commonly not available in most of the world and when it was approved was prescribed only off-label for ADHD. A seventh medication, bupropion is classified as an anti-depressant, but inhibits the reuptake of norepinephrine, and to a lesser extent, dopamine, in neuronal synspases,^[39] and so is noted in this paragraph. Unlike many of the stimulants used to treat ADHD, bupropion is not a controlled substance. See further information on Bupropion in the paragraph below.

 

There are also several nonstimulant medications that are used either by themselves or in conjunction with the stimulants. These are commonly Selective Norepinephrine Reuptake Inhibitors (SNRIs but not to be confused with Serotonin-Norepinephrine Reuptake Inhibitors also referred to as SNRIs) such as Atomoxetine (Strattera). These are also sometimes classified as Norepinephrine Reuptake Inhibitors (NRIs) for the confusion issue. Also, tricyclic anti-Depressants are occasionally prescribed, but they seem to only treat the hyperactive part of the condition.

 

There is research on a class of medications called Selective Serotonin Reuptake Enhancers (SSREs); currently, the only one available is Tianeptine (brand name Stablon; it is not available in North America or the English World); this is an atypical tricyclic anti-depressant which is inconclusive in its efficacy. Bupropion (Wellbutrin, commonly prescribed as Wellbutrin XL in a timed release form due to risk of side effects) is an anti-depressant which weakly inhibits the neuronal re-uptake of both norepinephrine and dopamine, but has little or no effect on seratonergic re-uptake.^[40] It is approved for ADHD and is not particularly known for its stimulant properties because at high doses it tends to cause seizures in a large portion of the population.

 

Because many of the medications used to treat ADHD are Schedule II under the U.S. Drug Enforcement Administration schedule system, and are considered powerful stimulants with a potential for abuse, there is controversy surrounding prescribing these drugs for children and adolescents. However, research studying ADHD patients who either receive treatment with stimulants or go untreated has indicated that those treated with stimulants are less likely to abuse any substance than ADHD sufferers who are not treated with stimulants.^[41]

 

Only recently, studies on the cost-effectiveness of ADHD treatment have begun to appear. To date valid information is limited, although a review presented identified 11 health technology assessments and cost-effectiveness analyses, all of which compared the economic merits of at least two treatment alternatives.^[42]

 

Many alternative treatments have been proposed for ADHD, though few in the mainstream medical community regarded them as viable in reducing symptoms significantly. The alternative treatments that have clinically shown some improvement in symptoms are the addition of magnesium and zinc to the diet and the elimination of red food dye.

 

Ginkgo is a natural supplement used by some to help control their ADHD symptoms.

There are indications that children with ADHD are metabolically different from others,[43][44][45] and it has therefore been suggested that diet modification may play a role in the management of ADHD. Perhaps the best known of the dietary alternatives is the Feingold diet which involves removing salicylates, artificial colors and flavors, and certain synthetic preservatives from children's diets.[46]   In the 1980s vitamin B6 was promoted as a helpful remedy for children with learning difficulties including inattentiveness. In 2006, a study demonstrated that children with autism had significantly lower magnesium than controls, and that the correction of this deficit was therapeutic.[47] Later, zinc and multivitamins have been promoted as cures, and currently the addition of certain fatty acids such as omega-3 has been proposed as beneficial.[48][49]

Mild stimulants such as caffeine and theobromine may improve the function of some children suffering from ADHD.^[50][51] ADHD Coaching is a program where coaches work with ADHD individuals to help them prioritize, organize, and develop life skills. Coaching is aimed at helping clients to be more realistic in setting goals for themselves by learning about their individual challenges and gifts, and emphasizes spending more time in areas of strength, while minimizing time spent dealing with areas of difficulty.

Prognosis

ADHD is a developmental disorder meaning that certain traits will be delayed in the ADHD individual. These traits will develop but just at a much slower rate then the average person. With ADHD it has been estimated that this lag could be as high as thirty to forty percent in the development of impulse control. Symptoms of ADHD are often seen by the time a child enters preschool. Those with ADHD typically have a greater degree of parent-child conflict and emotional reactivity. During the elementary years an ADHD student will have more difficulties with work completion, productivity, planning, remembering things needed for school, and meeting deadlines. They will also have an increased chance of failing a school year.^[52]

 

The incident of speech problems, central auditory processing difficulties, and coordination problems are all higher then that of the general population. A marked decrease in academic skills such as reading, spelling, or math is common with children who have ADHD. Only five percent of those with ADHD will get a college degree compared to thirty five or forty percent of the general population. Thirty seven percent of those with ADHD do not get a high school diploma even though many them will receive special education services.^[53]

 

Social impairment for those with ADHD are typically is seen in school or at work. They often have more troubled relationships with peers or family members. At the workplace they change jobs more often and are more likely to get fired. Their income level does not rise as quickly as their peers even when education level, IQ, and their neighborhood is accounted for. Thirty five percent of all ADHDers will be self employed in their mid-thirties. Those with ADHD are at greater risk of: injury, abnormal risk taking, smoking, having learning disabilities, other mental disorders, teen pregnancy, substance abuse, involvement with the criminal justice system, and having a poorer driving record.^[54]

 

Prevention

There is no known way to prevent ADHD. Some studies indicate an association between mothers who smoke during pregnancy and a higher rate of ADHD in their children. Avoiding smoking, alcohol, and drugs during pregancy may help prevent a higher risk of developing ADHD or similar behavior in offspring.

 

Epidemiology

ADHD has been found to exist in every country and culture studied to date. The prevalence among children and adults is estimated to be in the range of 4% to 8%.^[55][56][57] 10% of males, and (only) 4% of females have been diagnosed. This apparent sex difference may reflect either a difference in susceptibility or that females with ADHD are less likely to be diagnosed than males.^[58][59]

 

History

There are numerous historical and literary references to ADHD. In 493 BC, the great physician-scientist Hippocrates described a condition that seems to be compatible with what we now know as ADHD. He described patients who had "quickened responses to sensory experience, but also less tenaciousness because the soul moves on quickly to the next impression". Hippocrates attributed this condition to an "overbalance of fire over water”. His remedy for this "overbalance" was "barley rather than wheat bread, fish rather than meat, water drinks, and many natural and diverse physical activities."^[60]

 

Shakespeare made reference to a "malady of attention", in King Henry VIII. In 1845, ADHD was alluded to by Dr. Heinrich Hoffmann, a German physician who wrote books on medicine and psychiatry. Dr. Hoffmann was also a poet who became interested in writing for children when he couldn't find suitable materials to read to his 3-year-old son. The result was a book of poems, complete with illustrations, about children and their undesirable behaviors. "Die Geschichte vom Zappel-Philipp" (The Story of Fidgety Philip) in Der Struwwelpeter was a description of a little boy who could be interpreted as having attention deficit hyperactivity disorder.^[61] Alternatively, it may be seen as merely a moral fable to amuse young children at the same time as encouraging them to behave properly.

 

ADHD was first clinically observed by the English pediatrician George Still in 1902. In a series of lectures to the Royal College of Physicians in England, he described a condition which some have claimed is analogous to ADHD. Still described a group of children with significant behavioral problems, caused, he believed, by an innate genetic dysfunction and not by poor child rearing or environment.^[62] Analysis of Still's descriptions by Palmer and Finger indicated that the qualities Still described are not "considered primary symptoms of ADHD".^[63] Beginning in the twentieth century researchers began to look for the causes of ADHD. The 1918–1919 influenza pandemic left many survivors with encephalitis, affecting their neurological functions. Some of these exhibited immediate behavioral problems which correspond to ADHD. This caused many to believe that the condition was the result of injury rather than genetics. The concept of hyperactivity not being caused by brain damage was first described by Stella Chess as, ""Hyperactive Child Syndrome" in 1960.^[64] This caused a significant rift in the understanding of the disorder. Europe saw hyperkinesis as unusual and often associated it with retardation, brain damage, and conduct disorders and changes to the ICD were not made not made until 1994. In the USA by 1966, following observations that the condition existed without any objectively observed pathological disorder or injury, researchers changed the terminology from Minimal Brain Damage to Minimal Brain Dysfunction.^[65]

 

The treatment of ADHD began in 1937 when Dr. Bradley in Providence, RI reported that a group of children with behavioral problems improved after being treated with stimulant medication.^[66] In 1957 the stimulant methylphenidate (Ritalin) became available. It remains one of the most widely prescribed medications for ADHD in its various forms (Ritalin, Focalin, Concerta, Metadate, and Methylin). In 1975 Pemoline (Cylert) was approved by the FDA for use in the treatment of ADHD. While an effective agent for managing the symptoms, the development of liver failure in 14 cases over the next 27 years would result in the manufacturer withdrawing this medication from the market. Ritalin was first produced in 1950. Initially the drug was used to treat narcolepsy, chronic fatigue, depression, and to counter the sedating effects of other medications. The drug began to be used for ADHD in the 1960s and steadily rose in use. New delivery systems for medications were invented in 1999 that eliminated the need for multiple doses across the day or taking medication at school. These new systems include pellets of medication coated with various time-release substances to permit medications to dissolve hourly across an 8–12 hour period (Medadate CD, Adderall XR, Focalin XR) and an osmotic pump that extrudes a liquid methylphenidate sludge across an 8–12 hour period after ingestion (Concerta). In 2003 – Atomoxetine (Strattera) received the first FDA approval for a nonstimulant drug to be used specifically for ADHD. In 2007 Lisdexamfetamine becomes the first prodrug to receive FDA approval for ADHD. The landmark study of 1999 – The largest study of treatment for ADHD in history is published in the American Journal of Psychiatry. Known as the Multimodal Treatment Study of ADHD (MTA Study), it involved more than 570 children with ADHD at 6 sites in the United States and Canada randomly assigned to 4 treatment groups. Results generally showed that medication alone was more effective than psychosocial treatments alone, but that their combination was beneficial for some subsets of ADHD children beyond the improvement achieved only by medication. More than 40 studies have subsequently been published from this massive dataset.

 

Psychiatry first codified ADHD as “hyperkinetic reaction of childhood” in 1968, displaying the psychoanalytical influences of that time. The name Attention Deficit Disorder (ADD) was first introduced in DSM-III, the 1980 edition. By 1987 – The DSM-IIIR was released changing the diagnosis to "Undifferentiated Attention Deficit Disorder."^[67] Further revisions to the DSM were made in 1994 – DSM-IV described three groupings within ADHD, which can be simplified as: mainly inattentive; mainly hyperactive-impulsive; and both in combination. During 1996 – ADHD accounted for at least 40% of child psychiatry references.^[68] The 2002 – The International Consensus Statement on ADHD is published and signed by more than 80 of the world's leading experts on ADHD to counteract periodic media misrepresentation. The statement reaffirms ADHD is a "genuine disorder because the scientific evidence indicating it is so is overwhelming", "recognizes the mounting evidence of neurological and genetic contributions to this disorder", and that medications are justified as a treatment for the disorder. In 2005, another 100 European experts on ADHD added their signatures to this historic document certifying the validity of ADHD as a valid mental disorder.

 

Controversy

 

The ADHD diagnosis has been questioned by vocal social critics. They point out the positive traits that people with ADHD have, such as "hyperfocusing." Others believe ADHD is a divergent or normal-variant human behavior, and use the term neurodiversity to describe it, emphasizing that there are an immense number of variations in genetics which could favor a greater or lesser ability to concentrate and/or to remain calm under varying circumstances.^[69]

 

Positive aspects of ADHD

Although ADHD is considered a disorder, some view it in a neutral or positive light. Rather than assuming that ADHD is inherently negative, some argue that ADHD is simply a different method of learning as opposed to an inferior one. The aspects of ADHD which are generally viewed negatively can be a potential source of strength, such as willingness to take risks. Most frequently cited as potentially useful is the mental state of hyperfocus. Lists of famous persons with ADHD or who may have had ADHD include Albert Einstein, Thomas Edison, and Terry Bradshaw. JetBlue Airways founder David Neeleman may be the most well known proponent of this viewpoint. He considers ADHD one of his greatest assets and refuses to take medication.^[70][71]

 

References