Attention-Deficit Hyperactivity Disorder (ADHD) is a mental disorder, and is one of the most common neurodevelopmental disorders of childhood. It is usually first diagnosed in childhood and often lasts into adulthood. Children with ADHD may have trouble paying attention, controlling impulsive behaviors (may act without thinking about what the result will be), or be overly activewhich manifests itself with symptoms such as hyperactivity, forgetfulness, mood shifts, poor impulse control, and distractibility. In neurological pathology, ADHD is currently considered to be a chronic syndrome for which no medical cure is available.Pediatric patients as well as adults may present with ADHD, which is believed to affect between 3-5% of the human population.
Much controversy surrounds the diagnosis of ADHD, such as over whether or not the diagnosis denotes a disability in its traditional sense or simply describes a personal or neurological property of an individual. Those who believe that ADHD is a traditional disability or disorder often debate over how it should be treated, if at all. According to a majority of medical research in the United States, as well as other countries, ADHD is today generally regarded to be a non-curable neurological disorder for which, however, a wide range of effective treatments are available. Methods of treatment involve some combination of medication, psychotherapy, and other techniques. Many patients are able to control their symptoms over time, even without the use of medication. Some individuals who meet the diagnostic criteria of ADHD, according to the guidelines of the Diagnostic and Statistical Manual of Mental Disorders, do not consider themselves to be mentally ill, as the manual suggests, and therefore may remain undiagnosed or, after a positive diagnosis, untreated.
ADHD is most commonly diagnosed in children. When diagnosed in adults, it is regarded as adult attention-deficit disorder (AADD). It is believed that anywhere between 30 to 70% of children diagnosed with ADHD retain the disorder as adults.
- 1 Terminology
- 2 Formal definitions
- 3 Symptoms
- 4 Diagnosis
- 5 Incidence
- 6 Possible causes
- 7 Treatment
- 8 Controversy
- 9 Positive aspects
- 10 Timeline
- 11 See also
- 12 Further reading
- 13 External links
The most appropriate designation of ADHD is currently disputed; the terms below are known to be used to describe the condition. A difficulty in the condition's nomenclature arises when some scientific research suggests that certain behaviors are directly attributable to ADHD, while other research concludes that the same behaviors constitute disorders that need to be classified independently of ADHD. For the purposes of this article, the "Terminology" section will be used only to name ADHD and its near equivalents, while the names for its manifestations and subtypes will be listed in "Symptoms" section, below.
- Attention-deficit hyperactivity disorder (ADHD): In 1987, ADD was in effect renamed to ADHD in the DSM-III-R. In it, ADHD was broken down into three subtypes (see 'symptoms' for more details):
- predominantly inattentive ADHD
- predominantly hyperactive-impulsive ADHD
- combined type ADHD
- Attention deficit disorder (ADD): This term was first introduced in DSM-III, the 1980 edition. Is considered by some to be obsolete, and by others to be a synonym for the predominantly inattentive type of ADHD.
- Undifferentiated attention-deficit disorder (UADD): This term was first introduced in the DSM-III-R, the 1987 edition. This was a miscellaneous category, and no formal diagnostic criteria were provided. UADD is approximately the predominantly inattentive type of ADHD in the DSM-IV-TR. The DSM-III-R diagnosis of attention-deficit hyperactivity disorder required hyperactive-impulsive symptoms in addition to the inattentive symptoms.
- Attention-deficit syndrome (ADS): Equivalent to ADHD, but used to avoid the connotations of "disorder".
- Hyperkinetic disorders (F90) is the ICD-10 equivalent to ADHD. The ICD-10 does not include a predominantly inattentive type of ADHD because the editors of Chapter V of the ICD-10 believe the inattentivity syndrome may constitute a nosologically distinct disorder.
- Disturbance of activity and attention (F90.0)
- Hyperkinetic conduct disorder (F90.1) is a mixed disorder involving hyperkinetic symptoms along with presence of conduct disorder
- Other hyperkinetic disorders (F90.8)
- Hyperkinetic disorder, unspecified (F90.9)
- Hyperkinetic syndrome (HKS): Equivalent to ADHD, but largely obsolete in the United States, still used in some places world wide.
- Minimal cerebral dysfunction (MCD): Equivalent to ADHD, but largely obsolete in the United States, though still commonly used internationally.
- Minimal brain dysfunction or Minimal brain damage (MBD): Similar to ADHD, now obsolete.
From a developmental/behavioral standpoint, the Diagnostic and Statistical Manual of Mental Disorders-IV-TR states that ADHD is a developmental disorder that presents during childhood, in most cases before the age of seven, and is characterized by developmentally inappropriate levels of inattention and/or hyperactive-impulsive behavior. The DSM-IV also stipulates that in order to be diagnosed, the condition must also result in significant impairment of one or more major life activities, including interpersonal relations, educational or occupational goals, as well as cognitive or adaptive functioning. ADHD may be also diagnosed in adulthood, but symptoms must have been present prior to age seven in order to yield a positive diagnosis.
The symptoms of ADHD fall into the following two broad categories: Inattention:
- Failing to pay close attention to details or making careless mistakes when doing schoolwork or other activities
- Trouble keeping attention focused during play or tasks
- Appearing not to listen when spoken to
- Failing to follow instructions or finish tasks
- Avoiding tasks that require a high amount of mental effort and organization, such as school projects
- Frequently losing items required to facilitate tasks or activities, such as school supplies
- Excessive distractibility
- Fidgeting with hands or feet or squirming in seat
- Leaving seat often, even when inappropriate
- Running or climbing at inappropriate times
- Difficulty in quiet play
- Frequently feeling restless
- Excessive speech
- Answering a question before the speaker has finished
- Failing to await one's turn
- Interrupting the activities of others at inappropriate times
A positive diagnosis is usually only made if the patient presents with at least six of the above symptoms. In addition, a positive diagnosis is made if six or more of these symptoms presented before the age of seven; the symptoms usually begin to appear between the ages of four and six. Symptoms must appear consistantly in varied enviroments. (Ex: At home, school, and in public.)
Children who grow up with ADHD often continue to have symptoms as they grow into adulthood. Adults face some of their greatest challenges in the areas of self-control and self-motivation, as well as executive functioning (also known as working memory). If the patient is not treated appropriately, co-morbid conditions, such as depression and anxiety may present as well. If a patient presents with such conditions as well, the co-morbid condition is usually treated first.
The Centers for Disease Control and Prevention (CDC) emphasize 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 physical disorders, such as hyperthyroidism. Further, 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.
Due to the lack of objectivity that surrounds the critical factors, many question the reliability of ADHD diagnosis. The American Academy of Pediatrics Clinical Practice publishes guidelines to aid providers in making an objective diagnosis, but even if strictly adhered to, doubt still remains among some patients, as well as providers. Other diagnostic methods, such as those involving magnetic resonance imaging (MRI), may detect the presence of ADHD by analyzing images of the patient's brain, are usually not recommended (see brain scans). In a majority of cases, diagnosis is therefore dependent upon the observations and opinions of those who are close to the patient; in many patients, especially as they approach adulthood, self-diagnosis is not uncommon.
Publications that are designed to analyze a person's behavior, such as the Brown Scale or the Conners Scale, for example, attempt to assist parents and providers in making a diagnosis by evaluating an individual on typical behaviors such as "Hums or makes other odd noises", "Daydreams" and "Acts 'smart'"; the scales rating the pervasiveness of these behaviors range from "never" to "very often". Connors states that, based on the scale, a valid diagnosis can be achieved; critics, however, counter Connors' proposition by pointing out the breadth with which these behaviors may be interpreted. This becomes especially relevant when family and cultural norms are taken into consideration; this premise leads to the assumption that a diagnosis based on such a scale may actually be more subjective than objective (see cultural subjectivism). The scales are further critisized, because they were originally developed to measure the effectiveness of stimulant medication, and not to detect ADHD. Therefore, the scales might merely evaluate a patient's response to stimulant medication, such as Ritalin or Adderall, rather than the presence of ADHD.
The American Academy of Pediatrics Clinical Practice Guideline for children with ADHD emphasizes that a reliable diagnosis requires:
- 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 (especially from schools).
- The search for coexisting conditions that may make the diagnosis more difficult or complicate treatment planning.
A proper diagnosis is dependant upon a physician fufilling all three of these criteria. The first criteria can be satisfied by using an ADHD-specific instrument such as the Conners Scale. The second criteria is best fufilled by examining the individual's history. This history can be obtained from parents and teachers, or a patient's memory. 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.
Computerized tests of attention are not especially helpful in providing a further independent assessment because they have a high rate of false negatives (real cases of ADHD can pass the tests in 35% or more of cases), they do not correlate well with actual behavioral problems at home or school, and are not especially helpful in determining treatments. Both the American Academy of Pediatrics and American Academy of Child and Adolescent Psychiatry have recommended against the use of such computerized tests for now in view of their lack of appropriate scientific validation as diagnostic tools. In the USA, the process of obtaining referrals for such assessments is being promoted vigorously by the President's New Freedom Commission on Mental Health.
Neurometrics, PET scans, FMRI, or SPECT scans have the potential to provide a more objective diagnosis. However, these are not typically suitable for very young children, and may unnecessarily expose the patient to harmful radiation. Because the etiology of the disorder is unknown, and a complete neurological definition of this disorder is lacking, a majority of clinicians doubt the current predictive power of these objective tests to detect ADHD to be used to direct clinical treatment. Currently, the American Academy of Pediatrics and the American Academy of Child and Adolescent Psychiatry recommend against using these neuro-imaging methods for clinical diagnosis of individuals who may have ADHD. They remain, however, useful research tools when studying groups of patients with ADHD. An October 2005 meta-analysis by Alan Zametkin, M.D., with the NIMH entitled "The ADHD Report", concluded that these diagnostic methods lack adequate scientific research on accuracy and specificity to be used as a primary diagnostic tool.
ADHD has been found to exist in every country and culture studied to date. While it is most commonly diagnosed in the United States, rates of diagnosis are rising in most industrialized countries as they become more aware of the disorder, its diagnosis, and its management.
Nearly four million children younger than 18 in the United States had been diagnosed with attention deficit hyperactivity disorder (ADHD). The prevalence among children is estimated to be in the range of 5% to 8% in children, and 4% to 8% in adults. 10% of males, but only 4% of females have been diagnosed, indicating that ADHD may be a gender-specific disorder with a male/female ratio of almost 2:1 (exactly 2.5:1).
The ADHD treatment rate among Caucasian children is significantly higher than among African and Hispanic Americans (4.4% Caucasian, 1.7% African, 1.5% Hispanic in 1997). The same study notes that outpatient treatment for ADHD has grown from 0.9 children per 100 (1987) to 3.4 per 100 (1997).
Exactly what causes ADHD remains unknown. In 1998 NIH (US National Institutes of Health) called together most of the experts in this field. They issued a consensus statement. This is the next to last sentence of that report:  "Finally, after years of clinical research and experience with ADHD, our knowledge about the cause or causes of ADHD remains largely speculative. Consequently, we have no documented strategies for the prevention of ADHD." Similarly the Surgeon General states the etiology of ADHD is unknown. Numerous theories and speculations exist on the subject. For example, research indicates that the frontal lobes, their connections to the basal ganglia, and the central aspects of the cerebellum (vermis) may be involved in this disorder, as may be a region in the middle or medial aspect of the frontal lobe, known as the anterior cingulate. The cerebellum, which is believed to play important roles in "short-term memory, attention, impulse control, emotion, higher cognition, [and] the ability to schedule and plan tasks, has been shown to be smaller in the brains of those who have ADHD. It should be noted however, that non biological patterns of behavior can effect brain size. For example, learning Braille causes enlargement of the part of the motor cortex that controls finger movements. After they have passed their licensing exam, London taxi drivers have been found to have a significantly enlarged hippocampus (a part of the brain that stores memories (in this case spatial-visual memories))compared to non-taxi drivers Patients abused during their childhood with post traumatic stress disorder will have a flattened out hippocampus. Professional musicians have brains that are different from non-musicians. Monks who meditate show measurable differences in their prefrontal lobes.)
The source of claimed differences in those with ADHD is not yet known, but a couple of theories have been presented.
Hereditary dopamine deficiency
Research suggests that ADHD arises from a combination of various genes, many of which have something to do with dopamine transporters. Suspect genes include the 10-repeat allele of the DAT1 gene and the 7-repeat allele of the DRD4 gene, Other studies have documented an association between ADHD and the dopamine beta hydroxylase gene (DBH TaqI).
In addition, SPECT scans found people with ADHD to have reduced blood circulation, and a significantly higher concentration of dopamine transporters in the striatum which is in charge of planning ahead.
It has long been suggested that ADHD could be the result of a nutritional problem. Recent studies have begun to find metabolic differences in these children, indicating that an inability to handle certain elements of one's diet might contribute to the development of ADHD, or at least ADHD-like symptoms. For example, in 1990 the English chemist N.I. Ward showed that children with ADHD lose zinc when exposed to a food dye. Waring, McFadden, and others have shown that children with autism or ADHD are low in sulfation metabolism, in particular the enzyme Phenol Sulfotransferase-P. Some studies suggest that a lack of fatty acids, specifically omega-3 fatty acids can trigger the development of ADHD. Support for this theory comes from findings that breast-fed children are less likely to have ADHD than their bottlefed counterparts and until very recently, infant formula did not contain any omega-3 fatty acids at all. Time will tell whether or not this is coincidence or a true correlation.
There is no compelling evidence that social factors, alone, can create ADHD. (However, see discussion of parental role in section below) The few environmental factors implicated fall in the realm of biohazards including alcohol, tobacco smoke, and lead poisoning. Allergies (including those to artificial additives) as well as complications during pregnancy and birth-- including premature birth--might also play a role.
Smoking during pregnancy
It has been observed that women who smoke while pregnant are more likely to have children with ADHD. Nicotine is known to cause hypoxia (lack of oxygen) in the uterus, which may lead to brain damage in the unborn child. Smoking could therefore play a major role in the child's development of the disorder prior to birth.
Head injuries may cause a person to present with ADHD-like symptoms, possibly because of damage done to the patient's frontal lobes. Because symptoms were attributable to brain damage, earliest designations for ADHD was "Minimal Brain Damage".
Dopamine deficiency caused by sleep apnea
Another theory is that ADHD is caused by brief pauses in breathing (apnea) during infancy. In October 2004, Dr. Glenda Keating and Dr. Michael Decker of Emory University presented data at the Society for Neuroscience's annual meeting showing that repetitive drops in blood oxygen levels in newborn rats similar to that caused by apnea in some human infants is followed by a long-lasting reduction in dopamine levels, associated with ADHD. Apnea occurs in up to 85% of prematurely born human infants. It remains to be seen whether or not these findings can be replicated in human babies.
There are many options available to treat people diagnosed with ADHD. The options with the greatest scientific support include a variety of medications, behavior-changing therapies, and educational interventions.
Findings of a large randomized controlled trial suggest that:
- Medication alone is superior to behavioral therapy alone.
- The combination of behavioral therapy and medication has a small benefit over medication alone.
The first-line medication used to treat ADHD are mostly 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. The stimulants used include:
- Methylphenidate — Available in:
- Regular formulation, sold as Ritalin, Metadate, Focalin, or Methylin. Duration: 4–6 hours per dose. Usually taken morning, lunchtime, and in some cases, afternoon.
- Long acting formulation, sold as Ritalin SR, Metadate ER. Duration: 6–8 hours per dose. Usually taken twice daily.
- All-day formulation, sold as Ritalin LA, Metadate CD, Concerta (Methylphenidate Hydrochloride), Focalin XR. Duration: 10–12 hours per dose. Usually taken once a day.
- Amphetamines —
- Dextroamphetamine — Available in:
- Regular formulation, sold as Dexedrine. Duration: 4–6 hours per dose. Usually taken 2–3 times daily.
- Long-acting formulation, sold as Dexedrine Spansules. Duration: 8–12 hours per dose. Taken once a day.
- Adderall, a trade name for a mixture of dextroamphetamine and laevoamphetamine salts. — Available in:
- Methamphetamine — Available in:
- Regular formulation, sold as Desoxyn by Ovation Pharmaceutical Company. Banned in the US because of the abuse potential.
- Dextroamphetamine — Available in:
- Bupropion. A dopamine and norepinephrine reuptake inhibitor, marketed under the brand name Wellbutrin.
- Atomoxetine. A norepinephrine reuptake inhibitor (NRI) introduced in 2003, it is the newest class of drug used to treat ADHD, and the first non-stimulant medication to be used as a first-line treatment for ADHD. Available in:
- Once daily formulation, sold by Eli Lilly and Company as Strattera. This medicine doesn't have an exact duration. It is to be taken once or twice a day, depending on the individual, every day, and takes up to 6 weeks to begin working fully. If the intake schedule is interrupted, it may take a few weeks to begin working correctly again.
Second-line medications include:
- Benzphetamine — a less powerful stimulant. Research on the effectiveness of this drug is not yet complete.
- Provigil/Alertec/modafinil — Recently approved by FDA for the treatment of ADHD. Provides an alternative to traditional stimulants.
- Cylert/Pemoline — a stimulant used with great success until the late 1980s when it was discovered that this medication could cause liver damage. Although some physicians do continue to prescribe Cylert, it can no longer be considered a first-line medicine. In March 2005, the makers of Cylert announced that it would discontinue the medication's production.
- Clonidine — Initially developed as a treatment for high blood pressure, low doses in evenings and/or afternoons are sometimes used in conjunction with stimulants to help with sleep and because Clonidine sometimes helps moderate impulsive and oppositional behavior and may reduce tics.article
Because most of the medications used to treat ADHD are Schedule II under the U.S. DEA schedule system, and are considered powerful stimulants with a potential for diversion and abuse, there is controversy surrounding prescribing these drugs for children and adolescents. However, research studying ADHD sufferers who either receive treatment with stimulants or go untreated has indicated that those treated with stimulants are in fact much less likely to abuse any substance than ADHD sufferers who are not treated with stimulants.
There are many alternative treatments for ADHD, most of them heavily disputed or relegated to adjunct status with medication treatment. This section attempts to deal with the most prominent of the alternative treatments. Bear in mind that the term "alternative" may mean unscientific because there are little or no credible scientific studies to support these suggested interventions, rather than there being experimental evidence against the intervention.
As noted above there are indications that children with ADHD are metabolically different from others, Ward NI et al. (1990). The influence of the chemical additive tartrazine on the zinc status of hyperactive children: A double-blind placebo-controlled study. J Nutr Med; 1 (1). 51-58; Ward NI (1997). Assessment of chemical factors in relation to child hyperactivity. Journal of Nutritional & Environmental Medicine (Abingdon); 7 (4). 333-342; Oades et al (1998). childrenPlasma neuropeptide-Y levels, monoamine metabolism, electrolyte excretion and drinking behavior in children with attention-deficit hyperactivity disorder. Psychiatry Res. 1998; Aug 17;80(2):177-86. Note: When the author was contacted by email re the children drinking more but urinating less, and asked "where is the water going?" he said that he did not know, but assumed that there was something metabolic going on that was using it. Joshi et al. (2006). Therefore it is believed that diet modification may play a major 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. Granted, according to a recent meta-analysis, there is little scientific evidence for the effectiveness of the Feingold diet in treating ADHD specifically, but this could be because much research has focused on food dyes, and the diet eliminates much more than that.
In the 1980s vitamin B6 was promoted as a helpful remedy for children with learning difficulties including inattentiveness. After that, zinc was promoted for ADD and autism. Multivitamins later became the claimed solution. Thus far, no reputable research has appeared to support either of these claims, except in cases of malnutrition. Currently the addition of certain fatty acids such as omega-3, is thought to be beneficial, but there is not much evidence to support this either.
It is claimed by some with ADHD that commonly available mild stimulants such as caffeine and theobromine have similar effects to the more powerful drugs commonly used in treating the disorder. Herbal supplements such as gingko biloba are also sometimes cited. While there is no scientific evidence to support this claim, it is widely accepted by those who wish to avoid strong medication.
There has been a lot of interesting work done with neurofeedback and ADHD. Children are taught, using video game-like technology, how to control their brain waves. Although some clinical professionals consider the treatment promising, there is not yet sufficient evidence that it remains effective after the immediate treatment is complete. A thorough review of the scientific research by Sandra Loo, Ph.D. and Russell Barkley, Ph.D. (Developmental Neuropsychology 2005) concluded that neurofeedback does not have adequate support from appropriately conducted scientific studies to support it as an intervention at this time.
Audio visual entrainment uses light and sound stimulation to guide and change brainwave patterns. Compared to other technology based alternative treatments it is inexpensive but probably not covered by health insurance. It is safe for most but cannot be used by those suffering from photosensitive epilepsy due to the risk of triggering a seizure. There is no scientific evidence to support this treatment at this time nor does it appear to be consistent with current evidence on the causes of ADHD.
There exist several exercise programs based on cerebellar stimulation that are used to treat ADHD, Asperger's syndrome and many learning difficulties like dyslexia, dyspraxia, etc. Most prominent are the DORE program,the Learning Breakthrough Program™ and the Brain Gym®, based on Educational Kinesiology.
These programs include balance, coordination, eye and sensory exercises that specifically stimulate the cerebellum. As noted above several studies have shown that the cerebellums of children with ADHD are notably smaller than their non-ADHD counterparts. Cerebellar stimulation assumes that by improving the patient’s cerebellar function many of the symptoms can be reduced or even eliminated permanently.
ADD Coaches work with AD/HD individuals, helping them prioritize, organize, and work on other important life skills. They also help clients to learn about their specific challenges and gifts, thus helping clients to be more realistic in setting goals for themselves. Most coaches give emphasis to finding their client's strengths and arranging for them to spend more time in areas of strength, while minimizing time spent dealing with areas of difficulty that will not likely be helped by coaching or other interventions. While certain things may always be a challenge, ADD Coaching provides structure and support for helping individuals deal with those difficult tasks as well.
The ADHD diagnosis is controversial and has been questioned by some professionals, adults diagnosed with ADHD, and parents of diagnosed children. They point out the positive traits that people with ADD have, such as "hyperfocusing." Others believe ADHD is a divergent or normal-variant human behavior, and use the term neurodiversity to describe it.
Skepticism towards ADHD as a diagnosis
Many have wondered why the number of people diagnosed with ADHD in the U.S. and UK has grown so dramatically over a short period of time. One possiblity is the increase is due to improved methods of diagnosis and greater awareness of the disorder. However, critics, such as Dan P. Hallahan and James M. Kauffman, in their book Exceptional Learners: Introduction to Special Education, have complained that the ADHD diagnostic criteria are sufficiently general or vague to allow virtually anybody with persistent unwanted behaviors to be classified as having ADHD of one type or another, and that the symptoms are not supported by sufficient empirical data..
Another source of skeptism is that most people with ADHD have no difficulties concentrating when they are doing something that interests them, whether it is educational or entertainment. However, these objections have been rejected by the American Psychiatric Association, the American Psychological Association, the American Medical Association, the American Academy of Pediatrics and the U.S. Surgeon General.
Lack of definitive evidence
Even granting that ADHD, as defined by DSM IV, much remains controversial precisely because so little is truly understood. There are an infinite number variations in genetics which could favor a greater or lesser ability to concentrate and/or to remain calm under varying circumstances. But those who stress that parental and educational factors strongly influence children's ability to perform with motivated integrated behavior, argue that the millions upon millions of children diagnosed with ADHD do not have anything wrong with their brains.
The biological evidence, though repeated and repeated, when scrutinized more closely is not what it seems. For example Zametkin's impressive looking brain image at the beginning of this article, contrasting differences in brain activity in those with the diagnosis is a picture of those with and without the diagnosis while doing an assigned task. Thus a person (with ADHD) who is not doing the assigned task will have a different looking picture of the brain's activity on that basis alone. If brain imaging is done while one person moves their arm and another doesn't there will also be a demonstrable difference. In this particular case the so-called biological evidence may turn out to be inconclusive.
While a believer that ADHD is a biological condition Xavier Castellanos M.D., then head of ADHD research at the National Institute of Mental Health (NIMH), was very explicit about the extent of our biological information.
- Frontline: "How does ADHD work on the brain? What do we know about it?"
- Castellanos: "We don't yet know what's going on in ADHD..."
- Frontline: "Give me one true fact about ADHD."
- Castellanos "The posterior inferior vermis of the cerebellum is smaller in ADHD. I think that that is a true fact. It's taken about five years to convince myself that that's the case. That's about as much as I know--that I'm confident about..."
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According to one point of view there is no compelling evidence that parenting methods can cause ADHD in otherwise normal children (those presumably born with the disorder). Evidence does show that parents of ADHD children experience more stress and give more commands. In the context of this point of view further research suggests that such parenting behavior is in large part a reaction to the child's ADHD and related disruptive and oppositional behavior and in a small part the result of the parent's own ADHD.
In contrast to this perspective many clinicians believe that attachments and relationships with caregivers and other features of the environment in which the child's development occurs, have profound effects on attentional and self-regulatory capacities.. An editorial in a special editon of Clinical Psychology stated, "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."
Another point of view is that the behavior of those with ADHD is the "natural" way for children to behave. That traditionally enormous amounts of time and energy have been spent by parents and educators trying to teach a child how to: gain self control, act with consideration for others, and do tasks that are not fun. In other words, a child who is not taught how to behave and stay on task will display all of the symptoms of ADHD.
Though ADHD is classified as a serious disorder, some people have a different perspective and note the positive aspects. They argue that ADHD children tend to look at situations in a different manner, and that those with ADD tend to look beyond the norm. "While the A students are learning the details of photosynthesis, the ADHD kids are staring out the window and pondering if it still works on a cloudy day" (Underwood). Some children might be uneasy about getting into a situation. One positive side of impulsive behavior is the ability to try new things without trepidation. This can be a strength and a weakness: "Impulsivity isn't always bad. Instead of dithering over a decision, they're willing to take risks" (Underwood). JetBlue Airways founder David Neeleman believes that ADHD contributed to his business acumen and refuses to take medication for fear that he will lose his creativity. It should be kept in mind that more than 6000 studies have been done in this field and not a single one has found ADHD to convey any advantage over normal or control groups in these studies. However, this result can be predicted as it has long been a scientific assumption that ADHD is disadvantageous. Therefore there has been little serious research into neither the intellectual advantages it can provide, nor into conditions which might be necessary for taking advantage of ADHD traits. It might also be argued that while ADHD might not provide advantages on the average, upmentioned findings need not apply to the class of subjects with extraordinary achievements and, on the downside, extraordinary failures. Moreover, if, as some argue, ADHD basically describes the behavior of children who are not connecting to school and other tasks assigned to them, then studies that average out the accomplishments of all children possessing this difficulty would be meaningless, since so many different factors could lead to the same manifest behavior. Those not able to "go along with the program" might be among many things, future criminals, goof offs, dreamers, or supremely creative individuals having to do things their own way. An interesting example is Michael Flatley the man with the "Feet of Flames" creator of River Dance, winner at 17 of the all Ireland flute championship, once a golden glove competitor, who growing up in Chicago was an ADHD diagnosed Irish punk and charmer. 
Many professional counselors find it useful to emphasize to persons diagnosed with ADHD and their families the perspective that the condition does not necessarily block, and may even facilitate, great accomplishments. Most frequently cited as potentially useful is the mental state of hyperfocus. Lists of famous persons either diagnosed with ADHD or suspected (but not necessarily known to have had ADHD) are numerous, but currently lack scientific backup in most cases.
- 1845. ADHD was first alluded to by Dr. Heinrich Hoffmann, a physician who wrote books on medicine and psychiatry, Dr. Hoffman 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 characteristics. "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.http://www.fln.vcu.edu/struwwel/philipp_e.html Alternatively, it may be seen as merely a moral fable to amuse young children at the same time as encouraging them to behave properly.
- 1867 – The term "hyperactive" is first used in reference to the "condition of the brain in acute mania." (Source: Oxford English Dictionary Online)
- 1902 – The English pediatrician George Still, in a series of lectures to the Royal College of Physicians in England, 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. . Analysis of Still's descriptions by Palmer and Finger indicated that the qualities Still described are not "considered primary symptoms 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 ADD. This caused many to believe that the condition was the result of injury rather than genetics.
- 1937 – Dr. Bradley in Providence RI reported that a group of children with behavioral problems improved after being treated with stimulant medication. 
- 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, Medadate, and Methylin).
- 1960 – Stella Chess described "Hyperactive Child Syndrome" introducing the concept of hyperactivity not being caused by brain damage. (http://campus.houghton.edu/orgs/psychology/student/adhd/sld004.htm)
- 1961 – Ritalin first indicated for "various behaviour problems in children".
- 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. (Source: Oxford English Dictionary Online)
- 1970 – News reports that Ritalin was being prescribed to 5-10% of children in Omaha lead to national outcry and a Congressional inquiry.
- 1970s – Canadian Virginia Douglas released various publications to promote the idea that attention deficit was of more significance than the hyperactivity, influencing the American Psychiatric Association. http://faculty.ashrosary.org/faculty/counseling/ADHDNotes.htm
- ~1971 – The Church of Scientology set up the Citizen's Commission on Human Rights (CCHR), which lobbied using the media against psychiatric medication in general, and Ritalin in particular.
- 1973 – Dr Ben F. Feingold, Chief of Allergy at Kaiser Permanente Medical Center in San Francisco, claimed that hyperactivity was increasing in proportion to the level of food additives.
- 1975 – Pemoline (Cylert) is 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 at least 14 cases over the next 27 years would result in the manufacturer withdrawing this medication from the market.
- 1980 – The name Attention Deficit Disorder (ADD) was first introduced in DSM-III, the 1980 edition.
- 1987 – The DSM-IIIR was released changing the diagnosis to "Undifferentiated Attention Deficit Disorder." 
- 1991 – The U.S. Department of Education rules that ADHD is an eligible condition for receipt of special educational services provided that it interferes with academic functioning. Most cases are dealt with under the "Other Health Impaired" category of special education while others qualify under the categories for learning and emotional disorders.
- 1994 – DSM-IV described three groupings within ADHD, which can be simplified as: mainly inattentive; mainly hyperactive-impulsive; and both in combination.
- 1996 – ADHD accounted for at least 40% of child psychiatry references.
- 1998 – the NIH developed and issued a Consensus Statement attesting to the existence of ADHD. A link is provided in the External Links section below.
- 1999 – New delivery systems for medications are invented that eliminate 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).
- 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 ADHD children 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.
- 2001 – The International Consensus Statement on ADHD is published (Clinical Child and Family Psychology Review) and signed by more than 80 of the world's leading experts on ADHD to counteract periodic media misrepresentation that ADHD is not a real disorder and that medications are not 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.
- 2003 – Atomoxetine, the first new medication for ADHD in 25 years, receives FDA approval for use in children, teens, and adults with ADHD.
- Glossary of ADHD terms
- Adult attention-deficit disorder
- ADHD psychosis
- Auditory processing disorder
- Chemical imbalance theory
- Controversy about ADHD
- Developmental disability
- Educational psychology
- List of fictional characters with ADHD
- List of famous people with attention-deficit hyperactivity disorder
- National Institute of Mental Health
- Sensory integration disorder
- Sluggish cognitive tempo
- Texas Medication Algorithm Project
- David Keirsey
- Attention Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment (2006) by Russell A. Barkley, Ph.D. New York: Guilford Publications (guilford.com) (see also russellbarkley.org)
- Taking Charge of ADHD: The Complete Authoritative Guide for Parents (2005) by Russell A. Barkley, Ph.D. New York: Guilford Publications.
- Understanding ADD by Dr Christopher Green & Dr Kit Chee, ISBN 0-86824-587-9, Doubleday 1994
- The ADHD-Autism Connection: A Step toward more accurate diagnosis and effective treatment, by Diane M. Kennedy, ISBN 1578564980 (The aim of this book is to explore the similarities that attention deficit hyperactivity disorder (ADHD) shares with a spectrum of disorders currently known as pervasive developmental disorders.)
- Kate Kelly and Peggy Ramundo: You Mean I'm Not Lazy, Stupid, or Crazy?! A Self-Help Book for Adults with Attention Deficit Disorder (1993). ISBN 0-684-81531-1
- Edward M. Hallowell, M.D. and John J. Ratey, M.D. (2005). Delivered from Distraction: Getting the Most out of Life with Attention Deficit Disorder. Ballantine Books. ISBN 0-345-44230-X
- “Evaluation of an exercise-based treatment for children with reading difficulties" by David Reynolds, Roderick I. Nicolson and Helen Hambly, Version 3.4. Final (2003), retrieved December 1st, 2005.
- Opler LA, Frank DM, Ramirez PM. (2001) Psychostimulants in the treatment of adults with psychosis and attention deficit disorder. Annals of the New York Academy of Sciences, 931, 297-301.
- Bellak L, Kay SR, Opler LA. (1987) Attention deficit disorder psychosis as a diagnostic category. Psychiatric Developments, 5 (3), 239-63.
- Ninivaggi, F.J., "Attention-Deficit/Hyperactivity Disorder in Children and Adolescents: Rethinking Diagnosis and Treatment Implications for Complicated Cases," Connecticut Medicine. September 1999; Vol. 63, No. 9, 515-521.
- Hallahn, Dan P.; Kauffman, James M.. Exceptional Learners : Introduction to Special Education Allyn & Bacon; 10 edition (April 8, 2005)
- Skeptical Enquirer magazine; May/June 2006
- Castellanos, F. X., Giedd, J. N., Marsh, W. L., Hamburger, S. D., Vaituzis, A. C., Dickstein, D. P., Sarfatti, S. E., Vauss, V. C., Snell, J. W., Lange, N., Kaysen, D., Krain, A. L., Ritchie, G. F., Rajapakse, J. C., & Rapoport, J. L. (1996). Quantitative brain magnetic resonance imaging in attention-deficit hyperactivity disorder. Archives of General Psychiatry, 53, 607–616.