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'''Attention-deficit hyperactivity disorder (ADHD)''' is one of the most commonly diagnosed and controversial ]s among children, and is increasingly recognized as afflicting adults as well. Its symptoms include inattention, hyperactivity, and impulsivity. According to sources such as the ], the causes are currently unknown, and it is thought that the term covers a variety of related disorders. There is no single medical test that can accurately ] ADHD, though there are assessment tools. '''Attention-deficit hyperactivity disorder (ADHD)''' is one of the most commonly diagnosed and controversial ]s among children. In recent years, the diagnosis has increasingly been applied to adults as well. Its symptoms, based upon subjective evaluation criteria, include inattention, hyperactivity, and impulsivity.


According to most sources, including the ], the causes are currently unknown. Scientific speculation has largely centered upon apparent upregulation of ] function. It is thought that the term covers a variety of related disorders also related to dopamine upregulation. There are no objective medical tests that can accurately ] ADHD, though there are many subjective assessment tools, primarily promoted by the pharmaceutical industry. The diagnostic label is controversial because of its subjectivity, and this often leads to inappropriate medical intervention, according to critics of ].
⚫ The authoritative definition of ADHD is to be found in the ]'s

⚫ An 'authoritative' definition of ADHD is found in the ]'s
]-IV (Text Revision) ]-IV (Text Revision)
(DSM-IV-TR), which also defines three subtypes of ADHD: (DSM-IV-TR), which also defines three subtypes of ADHD:
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* Combined Type * Combined Type


According to some recent studies, ADHD is an inheritable dysfunction of ] metabolism mainly in the ] of the human ]. New studies consider the possibility that ] metabolism also affects this disorder (see ''Krause, Dresel, Krause in Psycho 26/2000 p.199ff''). One should note that almost all of the latest studies have been sponsored by drug companies. According to some recent studies, ADHD is an inheritable 'dysfunction' of ] metabolism mainly in the ] of the human ]. New studies consider the possibility that ] metabolism also affects this disorder (see ''Krause, Dresel, Krause in Psycho 26/2000 p.199ff''). One should note that '''almost all of the latest studies have been sponsored by drug companies'''.


==Terminology== ==Terminology==


There is not yet a naming consensus. Below are listed several terms that have been used, past and present. One challenge in taxonomy is that some patterns of behavior are labelled by experts symptoms or sub-types of ADHD, while other experts label those same patterns as their own disorders, independent 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', below. There is not yet a naming consensus. Below are listed several terms that have been used, past and present. One challenge in taxonomy is that some patterns of behavior are labeled by experts symptoms or sub-types of ADHD, while other experts label those same patterns as their own disorders, independent 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', below.


* '''Attention-deficit hyperactivity disorder''' (ADHD): In 1987, ADD was in effect renamed to ADHD in the ]. In it, ADHD was broken down into three subtypes (see 'symptoms' for more details): * '''Attention-deficit hyperactivity disorder''' (ADHD): In 1987, ADD was in effect renamed to ADHD in the ]. In it, ADHD was broken down into three subtypes (see 'symptoms' for more details):
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== Symptoms == == Symptoms ==


* In ''children'' the disorder is characterized by inattentiveness, impulsive behavior and restlessness. All of these symptoms may be present, or some of them may be lacking depending on the type of ADHD. Children with the inattentive type are actually often sluggish and hypo-active, contrary to popular notions about ADHD. * In ''children'' the disorder is characterized by inattentiveness to external direction, impulsive behavior and restlessness. All of these symptoms may be present, or some of them may be lacking depending on the type of ADHD. Children with the inattentive type are actually often sluggish and hypo-active, contrary to popular notions about ADHD.
* In ''adults'' the main problem is often their inability to structure their lives and plan simple daily tasks. Thus inattentiveness and restlessness often become secondary problems. * In ''adults'' the problem is often an inability to structure their lives and plan simple daily tasks. Thus, inattentiveness and restlessness often become secondary problems.


A diagnosis of ADHD is made based on a checklist of symptoms that can be found in ]. A hyperlink to the ] (CDC) web page summarizing these criteria is given in the ] section below. The CDC emphasizes that a diagnosis of ADHD should only be made by trained health care providers. A diagnosis of ADHD is made based on a checklist of symptoms that can be found in ]. A hyperlink to the ] (CDC) web page summarizing these criteria is given in the ] section below. The CDC emphasizes that a diagnosis of ADHD should only be made by trained health care providers. This is important as many of the criteria can be readily misinterpreted and the prescribed drugs can be very dangerous.
This is important as many of the criteria can be readily misinterpreted and the prescribed drugs can be very dangerous.


== Twentieth century history == == Twentieth century history ==


In ], the English ] ] described a condition analogous to ADHD. He regarded it as innate and not caused by the environment. In ], the English ] ] described a condition analogous to ADHD. He regarded it as innate and not caused by the environment.


The ] left many survivors with ], affecting their neurological functions. Some of these exhibited immediate behavioural problems which correspond to ADD. The ] left many survivors with ], affecting their neurological functions. Some of these exhibited immediate behavioural problems which correspond to ADD. This caused many to believe that the condition was the result of injury rather than genetics.
This caused many to believe that the condition was the result of injury rather than genetics.


In ], a group of children in an institution with behavioural problems were treated with ] drugs for the first time, resulting in behavioural improvements. In ], a group of children in an institution with behavioral problems were treated with ] drugs for the first time, resulting in behavioral changes appreciated as 'improvements' by caretakers. However, treatment with stimulants was not widely used until the late 1950s.
However treatment with stimulants was not widely used until the late 1950s.


In ], the new stimulant ] (]) became available. In ], the new stimulant ] (]) became available.


By the ]s and ]s, researchers changed the terminology from ''Minimal Brain Damage'' to ''Minimal Brain Dysfunction''. By the ]s and ]s, researchers changed the terminology from ''Minimal Brain Damage'' to ''Minimal Brain Dysfunction''.
This followed observations that the condition existed without any known injury. This followed observations that the condition existed without any objectively observed pathological disorder or known injury.


The "Hyperactive Child Syndrome" was first described in the 1960s, and was also regarded as not caused by injury. By the late 1960s and 1970s, ''hyperactivity'' had caught hold as a popular term, although ''MBD'' was also used professionally. The "Hyperactive Child Syndrome" was first described in the 1960s, and was also regarded as not caused by injury. By the late 1960s and 1970s, ''hyperactivity'' had caught hold as a popular term, although ''MBD'' was also still used professionally.


In the early ]s an erroneous newspaper article, which is still often cited, inflated the prescribing rate of medication by a factor of 10, influencing some to avoid treatment with stimulants. In the early ]s an erroneous newspaper article, which is still often cited, inflated the prescribing rate of medication by a factor of 10, influencing some to avoid treatment with stimulants.


In ] ], once a ] in ], claimed that hyperactivity was increasing in proportion to the level of food additives, and proposed a specific diet believing that it would help 50% of hyperactive children. In ] ], once a ] in ], claimed that hyperactivity was increasing in proportion to the level of food additives, and proposed a specific diet believing that it would help 50% of hyperactive children. The popularity of the claim caused an ] to investigate additives and encourage research.
The popularity of the claims caused an ] to investigate additives and encourage research.
Most carefully controlled studies showed that only 5% of ADD children showed behavioral effects from their diet (but this was obviously an important finding for that 5%), but some have shown a figure of 60%. One study tested the 50% who claimed to be helped by diet, finding that 10% showed behavioural changes from food triggers. Most carefully controlled studies showed that only 5% of ADD children showed behavioral effects from their diet (but this was obviously an important finding for that 5%), but some have shown a figure of 60%. One study tested the 50% who claimed to be helped by diet, finding that 10% showed behavioral changes from food triggers.
The ] excluded ]s, ], ]s and flavour ]s, as well as ]s that occur naturally in fruit such as ]es, ], ]s and ]s. However pineapple juice was suggested as a "safe" drink. The ] excluded ]s, ], ]s and flavour ]s, as well as ]s that occur naturally in fruit such as ]es, ], ]s and ]s. However pineapple juice was suggested as a "safe" drink.

Professional ]s exclude and re-introduce food groups on a more controlled basis to identify triggers. Professional ]s exclude and re-introduce food groups on a more controlled basis to identify triggers.


The Canadian ] in the early 1970s made various publications to promote the idea that attention deficit was of more significance than the hyperactivity, influencing the American Psychiatric Association. In the early 1970s, the Canadian ] released various publications to promote the idea that attention deficit was of more significance than the hyperactivity, influencing the American Psychiatric Association.

The name ''attention deficit disorder'' (ADD) was first introduced in DSM-III, the 1980 edition. The name ''attention deficit disorder'' (ADD) was first introduced in DSM-III, the 1980 edition.


The early ]s saw the ] B<small><sub>6</sub></small> promoted as a helpful remedy for children with learning difficulties including inattentiveness. After that, ] was promoted for ADD and ]. ]s later became the claimed solution. The early ]s saw the ] B<small><sub>6</sub></small> promoted as a helpful remedy for children with learning difficulties including inattentiveness. After that, ] was promoted for ADD and ]. ]s later became the claimed solution. It is claimed that no reputable research has appeared to support any of these claims, except in cases of ].
No reputable research has appeared to support any of these claims, except in cases of ].


In the mid-1980s, ] from ] took out a ] on certain tints for lenses to help those with reading problems associated with ]. In the mid-1980s, ] from ] took out a ] on certain tints for lenses to help those with reading problems associated with ].


In the late 1980s, the ] set up the ] (CCHR), which lobbied using the media against psychiatric medication in general, and ] in particular. In the late 1980s, the ] set up the ] (CCHR), which lobbied using the media against psychiatric medication in general, and ] in particular. They were very effective at the time in scaring people away from treatment with stimulants.
They were very effective at the time in scaring people away from treatment with stimulants, as well as increasing the social stigma.


In ], ] described three groupings within ADHD, which can be simplified as: mainly inattentive; mainly hyperactive-impulsive; and both in combination. In ], ] described three groupings within ADHD, which can be simplified as: mainly inattentive; mainly hyperactive-impulsive; and both in combination.
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==Incidence== ==Incidence==


According to the 2000 edition of ], ADHD affects three to seven ] of all children in the U.S. According to 2002 data from the ]'s annual ], released in 2004, nearly 4 million children younger than 18 in the United States had been diagnosed with attention deficit hyperactivity disorder (ADHD). However, rates of diagnosis vary widely even within the U.S. In some school districts as many as 60% of all children have been diagnosed with ADHD. According to the ] edition of ], ADHD affects three to seven ] of all children in the U.S. According to ] data from the ]'s annual ], released in ], nearly 4 million children younger than 18 in the United States had been diagnosed with attention deficit hyperactivity disorder (ADHD). However, '''rates of diagnosis vary widely even within the U.S. In some school districts as many as 60% of all children have been diagnosed with ADHD'''.


The 2002 data indicated that twice as many boys were diagnosed with ADHD as girls (10% vs. 4%). The causes of this gender disparity are unknown. Some experts theorize that ADHD is underdiagnosed in girls, since their symptoms tend to be less dramatic than those in boys and thus draw less attention from parents and teachers. The 2002 data indicated that twice as many boys were diagnosed with ADHD as girls (10% vs. 4%). The causes of this gender disparity are unknown. Some experts theorize that ADHD is underdiagnosed in girls, since their symptoms tend to be less dramatic than those in boys and thus draw less attention from parents and teachers.


Today ADHD is considered to be a problem all over the industrialized world, although in no other country are children diagnosed with this disorder as often as in the United States. Today ADHD is considered by some to be a problem all over the industrialized world, although in no other country are children diagnosed with this disorder as often as in the United States. Critics contend this is primarily a result of pharmaceutical industry marketing, essentially designed to increase sales globally.


The variation in the rates of diagnosis and in estimates of the rate of prevalence raises numerous issues. In fact, almost everything about ADHD has been the subject of intense debate, as discussed later in this article. The variation in the rates of diagnosis and in estimates of the rate of prevalence raises numerous issues. In fact, almost everything about ADHD has been the subject of intense debate, as discussed later in this article. This debate led the NIH to develop a ''Consensus Statement'' in 1998, a link to which is provided in the ] section
This debate led the NIH to develop a ''Consensus Statement'' in 1998,
a link to which is provided in the ] section
below. below.


ADHD often continues into adolescence and adulthood, and can cause a lifetime of frustrated dreams and emotional pain. However, children diagnosed with ADHD often go on to live normal lives, and wonder why their parents and schools felt the need to medicate them. Many complain of having needlessly suffered from the psychological trauma of the diagnosis and adverse effects of the drugs. Others have written of how diagnosis and treatment improved their lives. ADHD often continues into adolescence and adulthood, according to proponents of the diagnostic label, and can cause a lifetime of frustrated dreams and emotional pain. However, children diagnosed with ADHD often go on to live normal lives, and wonder why their parents and schools felt the need to medicate them. Many complain of having needlessly suffered from the psychological trauma of the diagnosis, social stigmatization, and adverse effects of the drugs. A grave concern often cited by critics is their concern that prescribed medications may cause persistent substance abuse problems. Others have written of how diagnosis and treatment improved their lives.


== Evidence for ADHD as an organic phenomenon == ==Evidence for ADHD as an organic phenomenon==


Brain imaging research using ] (MRI) has shown that differences exist between the brains of children with and without ADHD. Many scientists consider these results to be significant in themselves, but in addition ] studies have shown that there might be a link between a person's ability to pay continued attention and the use of ] - the body's major fuel - in the brain. In adults with ADHD, the brain areas that control attention use less glucose and appear to be less active, suggesting that a lower level of activity in some parts of the brain may cause inattention (''Zametkin et al.''). However, there is no evidence that this low level of glucose in fact causes the low level of attention; it could in fact be no more than an indicator for low attention. Maybe even more interesting are the results of some studies using ] (Single Photon Emission Computed Tomography). One study (''Lou et al. in Arch. Neurol. 46(1989) 48-52'') found that people with ADHD have a reduced blood circulation in the ]. But even more important might be the discovery that people with ADHD seem to have a significantly higher concentration of ] transporters in the ] (''Dougherty et al. in Lancet 354 (1999) 2132-2133; Dresel et al. in Eur.J.Nucl.Med. 25 (1998) 31-39''). Brain imaging research using ] (MRI) has shown that differences exist between the brains of children with and without ADHD, though these differences have not been shown in any way to be pathological in nature. Many scientists consider these results to be significant in themselves, but in addition ] studies have shown there might be a link between a person's ability to pay continued attention to external directives and the use of ] - the body's major fuel - in the brain. In adults diagnosed with ADHD, the brain areas that control attention use less glucose and appear to be less active, suggesting that a lower level of activity in some parts of the brain may cause inattention (''Zametkin et al.''). However, there is no evidence that this low level of glucose in fact causes the low level of attention to external direction; it could in fact be no more than an indicator for low attention, or in the alternative, superior self-direction.
Perhaps more interesting are the results of some studies using ] (Single Photon Emission Computed Tomography). One study (''Lou et al. in Arch. Neurol. 46(1989) 48-52'') found people labeled as ADHD have reduced blood circulation in the ]. But even more significant may be the discovery that people with ADHD seem to have a significantly higher concentration of ] transporters in the ] (''Dougherty et al. in Lancet 354 (1999) 2132-2133; Dresel et al. in Eur.J.Nucl.Med. 25 (1998) 31-39''). Researchers have also shown that individuals labeled as either bipolar or ADHD often have varient dopamine receptor alleles. Researchers have reported, for example, that DRD4 7 repeat alleles appear more frequently in certain aboriginal cultures with low population densities such as the Amazon, whereas DRD4 2 repeat alleles are expecially common in higher population density regions, including the Orient.


It has been known for some decades that ] can cause a person to experience and display ADHD-like symptoms. It has been known for some decades that ] can cause a person to experience and display ADHD-like symptoms.
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There is increasing evidence that variants in the gene for the dopamine transporter are related to the development of ADHD (Roman et al., 2004, Am J Pharmacogenomics 4:83-92.). This makes sense, as alterations in dopamine related sites in the brain have been identified in those diagnosed with ADHD and because dopamine transporter blockers are used to treat the disorder. However, it has been noted that although as many as 20 genes have been identified to be related to ADHD, none of them account for more than 5% of ADHD cases (Shastry, 2004, Neurochem Int 44:469-474.). This strongly suggests that not only is there no one gene that causes ADHD, it is unlikely that genetic factors are the major source of ADHD. There is increasing evidence that variants in the gene for the dopamine transporter are related to the development of ADHD (Roman et al., 2004, Am J Pharmacogenomics 4:83-92.). This makes sense, as alterations in dopamine related sites in the brain have been identified in those diagnosed with ADHD and because dopamine transporter blockers are used to treat the disorder. However, it has been noted that although as many as 20 genes have been identified to be related to ADHD, none of them account for more than 5% of ADHD cases (Shastry, 2004, Neurochem Int 44:469-474.). This strongly suggests that not only is there no one gene that causes ADHD, it is unlikely that genetic factors are the major source of ADHD.


== Other causes == ==Other possible causes==

⚫ ADHD is broadly defined and pervasive, and likely has many different causes. The initial trigger could be genetic, viral or bacterial infections, brain injury, or nutritional. There has been a surge in alternative approaches to ADHD, but these have not been widely accepted. Dietary factors have in particular been touted as important, but research has not strongly supported these claims. At best, there are small numbers of children that are sensitive to dyes and other food additives, sugar, caffeine, etc. (Jacobson and Schardt, 1999, Diet, ADHD & Behavior, Center for Science in the Public Interest, Washington, DC). A more promising possibility comes from the observation that children of women who smoked during pregnancy are more likely to be diagnosed with ADHD (Kotimaa et al., 2003, J Am Acad Child Adol Psychiatry 42, 826-833). Given that ] is known to cause hypoxia (too little oxygen) in the uterus, and that hypoxia causes brain damage, smoking during pregnancy may very well be an important contributing factor leading to ADHD. It may even help explain the increase in cases of ADHD, as there has been an increase in the number of women smokers. Unfortunately, there are not enough women smoking during pregnancy to account for all the cases of ADHD. What then are the other causes?
ADHD is broadly defined and pervasive, and the symptoms attributed to ADHD likely have a variety of different causes. The initial triggers could include genetic vulnerabilities, viral or bacterial infections, brain injury, or nutritional deficits. There has been a surge in alternative approaches to ADHD, but these have been vigorously disputed, paticularly by the pharmaceutical industry. Dietary factors have in particular been touted as important, but research primarily funded by the industry has obfuscated support for these claims. It has been established conclusively that there are children that are sensitive to dyes and other food additives, sugar, caffeine, etc. (Jacobson and Schardt, 1999, Diet, ADHD & Behavior, Center for Science in the Public Interest, Washington, DC).

⚫ The finding of another probable cause stemmed from the observation that children of women who smoked during pregnancy are more likely to be diagnosed with ADHD (Kotimaa et al., ], J Am Acad Child Adol Psychiatry 42, 826-833). Given that ] is known to cause ] (too little oxygen) in the uterus, and that hypoxia causes brain damage, smoking during pregnancy is likely an important contributing factor leading to ADHD. It may even help explain in part the increase in ADHD diagnoses, as the number of women smokers has increased. However, there are not nearly enough women smoking during pregnancy to account for all the ADHD diagnoses. What then are the other causes?


A number of different lines of research may be converging on an answer, or at least part of the answer. First, neuroscientists have determined that the dopamine system does appear to be central to the disorder, and certain changes in this system are consistently seen in those with ADHD. Second, certain essential fatty acids, ], have received increasing attention from nutrition researchers as being essential for brain development. This family of compounds has been directly tied into function of the dopamine system, and appears to be of critical importance in formation and maintenance of these systems. Third, clinical nutritionists have noted that ADHD children are deficient in omega-3 fatty acids, and that supplementation with various fatty acids may reduce some of the symptoms of ADHD. A number of different lines of research may be converging on an answer, or at least part of the answer. First, neuroscientists have determined that the dopamine system does appear to be central to the symptoms of the diagnosis, and certain changes in this system are consistently seen in those labeled as having ADHD. Second, certain essential fatty acids, ], have received increasing attention from nutrition researchers as being essential for healthy brain development. This family of compounds has been directly tied into function of the dopamine system, and appears to be of critical importance in formation and maintenance of these systems. Third, clinical nutritionists have noted that ADHD labeled children are often deficient in omega-3 fatty acids, and that supplementation with various fatty acids may reduce some of the symptoms.


Is there really a connection between omega-3 fatty acids and ADHD? The research has been conducted by scientists in three very different areas who do not ordinarily communicate with each other. This means no one has directly studied the possibility. However, the findings in each area are very suggestive. If the connection between omega-3 fatty acids is true, then dietary supplementation could be an effective prevention for the disorder, and could be an alternative treatment that would be less costly, have fewer adverse effects, and would ultimately fix the root problem, unlike the current drug treatments. Is there really a connection between omega-3 fatty acids and ADHD? The research supporting such a connection was conducted by scientists in three very different areas who do not ordinarily communicate with each other. This means no one has specifically studied the possibility. However, the findings in each area are very suggestive. If the connection between omega-3 fatty acids is true, then dietary supplementation could be an effective prevention for the disorder, and could be a less costly alternative treatment, with fewer adverse effects, and would ultimately address the root problem, unlike current psychotropic drug treatments.


The nutritional data has been well summarized in a review article (Burgess et al., 2000, Am J Clin Nutr 71:327-330). Children with ADHD have lower levels of key fatty acids. In fact, one study found that the lower the levels, the worse the symptoms. The possibility that fatty acid deficiency is a trigger for ADHD is especially plausible as nutrition scientists have recently demonstrated that the American diet is extremely deficient in omega-3 fatty acids. At the same time, the incidence of ADHD is rapidly increasing. More support for this idea comes from the findings that breast-fed children have much lower levels of ADHD, and that until quite recently, infant formula contained NO omega-3 fatty acids. These findings are only correlational, and do not prove a causal connection. The nutritional data has been well summarized in a review article (Burgess et al., 2000, Am J Clin Nutr 71:327-330). Children with ADHD have lower levels of key fatty acids. In fact, one study found that the lower the levels, the worse the symptoms. The possibility that fatty acid deficiency is a trigger for ADHD is especially plausible as nutrition scientists have recently demonstrated that the American diet is extremely deficient in omega-3 fatty acids. At the same time, ADHD diagnoses are rapidly increasing. More support for this idea comes from findings that breast-fed children have much lower levels of ADHD, and that until quite recently, infant formula contained '''NO''' omega-3 fatty acids. These findings are only correlational, and do not prove a causal connection.


Initial studies with supplementation with various fatty acids found improved cognitive function, visual acuity, and reduction of at least some of the symptoms of ADHD. These findings are similar to those in which improved cognitive function and increased IQ are seen in breastfed children—who get more fatty acids from their mother’s milk than do formula-fed infants. The data from these studies are promising, but inconsistent. Why did only some of the studies see an effect, and why were only some symptoms improved? These questions cannot be answered unless one knows about the effects of these fatty acids on the dopamine system. Initial studies with supplementation with various fatty acids found improved cognitive function, visual acuity, and reduction of at least some of the symptoms of ADHD. These findings are similar to those in which improved cognitive function and increased IQ are seen in breastfed children, who get more fatty acids from their mother’s milk than do formula-fed infants. The data from these studies are promising, but as yet inconsistent. Why did only some of the studies see an effect, and why were only some symptoms improved? These questions cannot be answered unless one knows about the effects of these fatty acids on the dopamine system, and the economic realities regarding who is funding studies attempting to debunk the correlation.


Making an adult lab rat deficient in omega-3 fatty acids results in big changes in the number of dopamine receptors and the amounts of dopamine in different parts of the brain responsible for learning, memory, and attention. Not surprisingly, adding n-3 fatty acids reversed these effects. More interesting studies have looked at developmental effects. If female rats are fed a diet deficient in n-3 fatty acids and then become pregnant, their offspring show marked changes in the dopamine areas of the brain that look like those seen in ADHD children and in the spontaneously hyperactive rat (Acar et al., 2003, Neurosci Res 45:375-382). The pups were also hyperactive. Supplementation of the female rats’ diet either during pregnancy or while nursing prevented this from happening. However, supplementing the pups’ diet after weaning only partially reversed the effects. This means that supplementation will only be partially effective as a treatment. Changing the diet of pregnant women and their infants and toddlers will be necessary to maximize the effectiveness of n-3 fatty acids in preventing ADHD. Making an adult lab rat deficient in omega-3 fatty acids results in significant metabolic changes, in the number of dopamine receptors and the amounts of dopamine in different parts of the brain responsible for learning, memory, and attention. Not surprisingly, adding n-3 fatty acids reversed these effects. More interesting studies have looked at developmental effects. If female rats are fed a diet deficient in n-3 fatty acids and then become pregnant, their offspring show marked changes in the dopamine areas of the brain, which look like those seen in ADHD-labeled children, and in the spontaneously hyperactive rat (Acar et al., 2003, Neurosci Res 45:375-382). The pups were also hyperactive. Supplementation of the female rats’ diet either during pregnancy or while nursing prevented this from happening. However, supplementing the pups’ diet after weaning only partially reversed the effects. This means that supplementation will only be partially effective as a treatment. Changing the diet of pregnant women and their infants and toddlers will be necessary to maximize the effectiveness of n-3 fatty acids in preventing ADHD symptoms.


There is also new evidence that brief pauses in breathing (apnea) during infancy may be a cause of ADHD. Dr. Glenda Keating of Emory University presented data at the Society for Neuroscience annual meeting in October 2004, 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. () There is also new evidence that brief pauses in breathing (]) during infancy may be a cause of ADHD. Dr. Glenda Keating of ] presented data at the ] annual meeting in October 2004, 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. ()


== Positive aspects == == Positive aspects ==


Though ADHD is classified as a serious disorder, many people have a different perspective. Some see it as a gift. In his book ''ADD - Attention Deficit Disorder'' (1997), Thom Hartmann developed the idea that people having ADHD symptoms may have simply inherited a collection of genes that were selected for when hunting was particularly important. This idea is the basis of another of his works, ''The Edison Gene: ADHD and the Gift of the Hunter Child'' (2003). Though ADHD is classified as a serious disorder, many people have a different perspective. Some see it as a gift. In his book ''ADD - Attention Deficit Disorder'' (1997), ] developed the idea that people having ADHD symptoms may have simply inherited a collection of genes that were selected for when hunting was particularly important. This idea is the basis of another of his works, ''The Edison Gene: ADHD and the Gift of the Hunter Child'' (2003).


People who believe that ADHD is a gift find hints of ADHD in the lives of many famous people in history. Though such ''post mortem'' diagnosis is questionable, it is intriguing to ponder the evidence that people such as ] might have been diagnosed as having ADHD if the current DSM criteria had been developed sufficiently long ago. Other historical figures who have been proposed as ADHD candidates include: ], ], ], ], ], ] and ], ], ], ] and the ]. People who believe that ADHD is a gift find hints of ADHD in the lives of many famous people in history. Though such ''post mortem'' diagnosis is questionable, it is intriguing to ponder the evidence that people such as ] might have been diagnosed as having ADHD if the current DSM criteria had been developed long ago. Other historical figures who have been proposed as ADHD candidates include: ], ], ], ], ], ] and ], ], ], ] and the ].


Some contemporary ADHD candidates have also been proposed, including Some contemporary ADHD candidates have also been proposed, including
], ] and ]. ], ] and ].


To see ADHD as a gift may seem somewhat problematic to anxious parents but it is at least a perspective that should be kept in mind. To see ADHD as a gift may seem somewhat problematic to anxious parents, and especially to the pharmaceutical industry, but it is at least a perspective that should be kept in mind.


== Psychological testing for ADHD == == Psychological testing for ADHD ==


Psychological testing for ADHD generally consists of obtaining multiple types of assessments. These usually include a clinical interview reviewing the DSM-IV criteria for ADHD. The interview also needs to rule out as much as possible other types of syndromes which can cause attention problems, such as depression, anxiety, and psychosis. Rating scales can be administered which provide measurement of the person's own view of their symptoms, as well as the views of parents, teachers, and significant others. Finally, computerized tests of attention can be helpful in providing a further independent assessment. These different assessments may not be in total agreement but provide a well-rounded view of the person's difficulties. A physician need not order psychological testing in order to make the diagnosis of ADHD, but many doctors use this kind of assessment to avoid over-diagnosis and treatment. Psychological testing for ADHD symptoms generally consists of obtaining multiple types of assessments. These usually include a clinical interview reviewing the DSM-IV criteria for ADHD diagnosis. The interview also needs to rule out as much as possible other types of syndromes which can cause attention problems, such as depression, anxiety, and psychosis. External social and environmental influences are given scant attention, as internal disorders are an assumption of the standard diagnostic protocols for ADHD. Rating scales can be administered which provide measurement of the person's own view of their symptoms, as well as the views of parents, teachers, and significant others. Finally, computerized tests of attention can be helpful in providing a further independent assessment. These different assessments may not be consistent, but do provide a view of the person's difficulties. Subjectivity of the analysis can be compounded by the fact that physicians generally need not order psychological testing in order to make the diagnosis of ADHD, but many doctors use this kind of assessment to avoid over-diagnosis and treatment. The process of obtaining referals for such assessments is being pushed vigorously by the pharmaceutical industry, in the guise of the ]


], ] scans, or ] scans have been used for a more objective diagnosis. ], ] scans, or ] scans have been used for a more objective diagnosis.
These are not usually suitable for very young children. These are not usually suitable for very young children.


Attention deficit disorder also exists in adults, and an assessment for this is also needed. Attention deficit disorder also is diagnosed in adults, and an assessment for this is also needed.


== Skepticism towards ADHD as a diagnosis == == Skepticism towards ADHD as a diagnosis ==


It should be noted that many creative individuals exhibit the characteristics of ADD or ADHD by virtue merely of the natural diversity of their paths of thinking. As in the case of many, if not all, others who exhibit the characteristics, there is no cause to suppose that it is ''their'' constitution, and not that of society generally, that is a condition to be rectified. It should be noted that many, if not most, creative individuals exhibit the characteristics of ADD, or ADHD, by virtue merely of their naturally divergent paths of thinking. As in the case of many, if not all, others who exhibit such characteristics, there is no cause to suppose that it is ''their'' constitution, rather than that of society generally, that is the condition needing to be rectified.


Critics have complained that the ADHD diagnostic criteria are sufficiently general or vague to allow most children with persistent unwanted behaviors to be classified as having ADHD of one type or another. This can be seen as diluting the perceived importance of the disorder. ]s are often subject to ] restrictions, preventing a wider awareness of their specificity. Critics have complained that the ADHD diagnostic criteria are sufficiently general or vague to allow virtually any child with persistent unwanted behaviors to be classified as having ADHD of one type or another. Such a wide diagnostic net can also be seen as diluting the perceived significance of the disorder. ]s are often subject to ] restrictions, preventing a wider awareness of their specificity.


Many people have wondered why the number of children diagnosed with ADHD in the U.S. and UK has grown so dramatically over a short period of time. It has often been suggested that the causes of the ADHD epidemic lie in cultural patterns that variously encourage or sanction the use of drugs as a simple cure for complex problems. Some critics assert that many children are diagnosed with ADHD and put on drugs as a substitute for parental attention, whereas many parents of ADHD children assert that the associated demand for attention goes beyond what can be humanly provided, causing massive disruption to other individuals and relationships, as well as to environments with structured relationships such as classrooms. This criticism also includes the use of prescription drugs as a substitute for parental duties such as communication and supervision. Many people, including a growing number of critics, have wondered why the number of children diagnosed with ADHD in the U.S. and UK has grown so dramatically over a short period of time. It has often been suggested that the causes of the apparent ADHD epidemic lie in cultural patterns that variously encourage or sanction the use of drugs as a simple and expeditious cure for complex problems that may stem primarily from social and environmental triggers rather than any innate disorder. Some critics assert that many children are diagnosed with ADHD and put on drugs as a substitute for parental attention, whereas many parents of ADHD children assert that the associated demand for attention goes beyond what can be humanly provided, causing massive disruption to other individuals and relationships, as well as to environments with dysfunctionally structured relationships such as are manifest in many classrooms. This criticism also includes the use of prescription drugs as a substitute for parental duties such as communication and supervision.


Some schools have required "problem" pupils to undergo ADHD diagnosis (and treatment if diagnosed), which has caused protests. Some critics have suggested that the ADHD label should be abolished. Some schools have required 'problem' pupils to undergo ADHD diagnosis (and treatment if diagnosed), which has caused protests. Some parents are alleged to have been threated with, or subjected to, child abuse charges for not allowing their children to be treated with psychotropic drugs. Some critics have suggested that the ADHD label should be abolished altogether.


], among other critics of ADHD diagnosis, suggest that the disorder may be a result of cultural conditions to which children and adults alike are subjected. Primary among these is the omnipresence and exploitive qualities of advertising. In the time that ADHD has arisen as the epidemic it is often portrayed as, advertisement has become virtually unavoidable, and advertisements utilize much more sophisticated methods of deception. Some suggest that people (children, especially) are aware of this attempt at pervasive trickery, whether consciously or subconsciously, and react by avoiding extended attention in order to avoid being deceived. Naturally, this self-defense reaction, when carried over to school and home, presents obvious problems. From this point of view, prescribing drugs is effectively only to alleviate symptoms, but entirely avoids the cause. ], among other critics of ADHD diagnosis, suggest that the disorder may be primarily the result of cultural conditions to which children and adults alike are subjected. Primary among these is the omnipresence and exploitive qualities of advertising. In the time that ADHD has arisen as the epidemic it is often portrayed as, advertisement has become virtually unavoidable, and advertisements utilize much more sophisticated methods of deception. Some suggest that people (children, especially) are aware of this attempt at pervasive trickery, whether consciously or subconsciously, and react by avoiding extended attention in order to avoid being deceived. Naturally, this self-defense reaction, when carried over to school and home, presents obvious problems. From this point of view, prescribing drugs is effectively only to alleviate symptoms, but entirely avoids the cause.


Thom Hartmann, among others take an approach from biological evolution to argue, that ADHD is not a disorder, but an expression of biodiversity. From an evolutionary point it is quite acceptable that humans&mdash;like other animals&mdash;differ in their biology and pass on their traits from generation to generation. It has not yet been proven wrong that ADHD indeed could be a product of human evolution, and therefore not necessarily a disability, disorder, condition or mental illness. Thom Hartmann, among others, takes an approach from biological evolution to argue that ADHD is not a disorder, but an expression of biodiversity. From an evolutionary point of view, it is quite acceptable that humans&mdash;like other animals&mdash;differ in their biology and pass on their traits from generation to generation. It has not yet been proven wrong that ADHD symptoms indeed could be a product of advantageous human evolutionary adaptations, and therefore not necessarily a disability, disorder, condition or mental illness.


Another source of skeptism towards making the diagnosis of "ADHD or not ADHD" may arise from the rising diagnosis of subclinical forms of ADHD. So called "Shadow-syndromes" or "sub-syndromes" stand for weaker forms of ADHD and are described in various degrees by John J. Ratey and Catherine Johnson on their book "Shadow Syndromes: The Mild Forms of Major Mental Disorders That Sabotage Us". Another source of skeptism towards making the diagnosis of "ADHD or not ADHD" may arise from the rising diagnosis of subclinical forms of ADHD. So called 'Shadow-syndromes' or 'sub-syndromes' stand for weaker forms of ADHD and are described in various degrees by John J. Ratey and Catherine Johnson on their book ''Shadow Syndromes: The Mild Forms of Major Mental Disorders That Sabotage Us''.


== Treatment == == Treatment ==
Line 166: Line 169:
Second-line medications include less-powerful stimulants such as ] and ]/], although research as to the efficacy of these drugs is not complete. Second-line medications include less-powerful stimulants such as ] and ]/], although research as to the efficacy of these drugs is not complete.


Data from 1995 show that physicians treating children and adolescents wrote six million prescriptions for stimulants. Of all the drugs used to treat psychiatric disorders in children, stimulant medications are the most well-studied. However, to date there are no good long-term studies dealing with stimulants in children. A 1998 Consensus Development Conference on ADHD sponsored by the ] and a recent, comprehensive, scientific report confirmed many earlier studies showing that short-term use of stimulants is safe and effective for children with ADHD. This says nothing for the growing number of children who are on stimulants for years at a time. Data from 1995 show that physicians treating children and adolescents wrote six million prescriptions for stimulants. Of all the drugs used to treat psychiatric disorders in children, stimulant medications are the most well-studied. However, to date there are no good long-term studies dealing with stimulants in children, and concerns exist pertaining to the ethics of conducting experiments involving children. A ] Consensus Development Conference on ADHD sponsored by the ] and a recent, comprehensive, scientific report confirmed many earlier studies showing that short-term use of stimulants is safe and effective for children with ADHD. This says nothing for the growing number of children who are on stimulants for years at a time. Some non-stimulant medications are now becoming available to treat ADHD such as ] (atomoxetine HCl), a selective ] reuptake inhibitor.
Some non-stimulant medications are now becoming available to treat ADHD such as ] (atomoxetine HCl), a selective ] reuptake inhibitor.


In December 1999, NIMH released the results of a study of nearly 600 elementary school children, ages seven-to-nine, which evaluated the safety and relative effectiveness of the leading treatments for ADHD for a period up to fourteen months. The results indicate that the use of stimulants alone is more effective than behavioral therapies in controlling the core symptoms of ADHD - inattention, hyperactivity/impulsiveness, and aggression. In other areas of functioning, such as anxiety symptoms, academic performance, and social skills, the combination of stimulant use with intensive behavioral therapies was consistently more effective. (Of note, families and teachers reported somewhat higher levels of satisfaction for those treatments that included the behavioral therapy components.) NIMH researchers will continue to track these children into adolescence to evaluate the long-term outcomes of these treatments, and ongoing reports will be published. This study has been severely criticized, as it was not double-blind and the sponsors failed to provide a control group. In December 1999, NIMH released the results of a study of nearly 600 elementary school children, ages seven-to-nine, which evaluated the safety and relative effectiveness of the leading treatments for ADHD for a period up to fourteen months. The results indicate that the use of stimulants alone is more effective than behavioral therapies in controlling the core symptoms of ADHD - inattention, hyperactivity/impulsiveness, and aggression. In other areas of functioning, such as anxiety symptoms, academic performance, and social skills, the combination of stimulant use with intensive behavioral therapies was consistently more effective. (Of note, families and teachers reported somewhat higher levels of satisfaction for those treatments that included the behavioral therapy components.) NIMH researchers will continue to track these children into adolescence to evaluate the long-term outcomes of these treatments, and ongoing reports will be published. This study has been severely criticized, as it was not double-blind and the sponsors failed to provide a control group.

Revision as of 22:40, 27 March 2005

Attention-deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and controversial mental disorders among children. In recent years, the diagnosis has increasingly been applied to adults as well. Its symptoms, based upon subjective evaluation criteria, include inattention, hyperactivity, and impulsivity.

According to most sources, including the CDC, the causes are currently unknown. Scientific speculation has largely centered upon apparent upregulation of dopamine function. It is thought that the term covers a variety of related disorders also related to dopamine upregulation. There are no objective medical tests that can accurately diagnose ADHD, though there are many subjective assessment tools, primarily promoted by the pharmaceutical industry. The diagnostic label is controversial because of its subjectivity, and this often leads to inappropriate medical intervention, according to critics of biological psychiatry.

An 'authoritative' definition of ADHD is found in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders-IV (Text Revision) (DSM-IV-TR), which also defines three subtypes of ADHD:

  • Predominantly Inattentive
  • Predominantly Hyperactive-Impulsive
  • Combined Type

According to some recent studies, ADHD is an inheritable 'dysfunction' of dopamine metabolism mainly in the frontostriatal region of the human brain. New studies consider the possibility that norepinephrine metabolism also affects this disorder (see Krause, Dresel, Krause in Psycho 26/2000 p.199ff). One should note that almost all of the latest studies have been sponsored by drug companies.

Terminology

There is not yet a naming consensus. Below are listed several terms that have been used, past and present. One challenge in taxonomy is that some patterns of behavior are labeled by experts symptoms or sub-types of ADHD, while other experts label those same patterns as their own disorders, independent 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', 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.
  • Attention-deficit syndrome (ADS): Equivalent to ADHD, but used to avoid the connotations of "disorder".
  • 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.

Symptoms

  • In children the disorder is characterized by inattentiveness to external direction, impulsive behavior and restlessness. All of these symptoms may be present, or some of them may be lacking depending on the type of ADHD. Children with the inattentive type are actually often sluggish and hypo-active, contrary to popular notions about ADHD.
  • In adults the problem is often an inability to structure their lives and plan simple daily tasks. Thus, inattentiveness and restlessness often become secondary problems.

A diagnosis of ADHD is made based on a checklist of symptoms that can be found in DSM-IV-TR. A hyperlink to the Centers for Disease Control and Prevention (CDC) web page summarizing these criteria is given in the External links section below. The CDC emphasizes that a diagnosis of ADHD should only be made by trained health care providers. This is important as many of the criteria can be readily misinterpreted and the prescribed drugs can be very dangerous.

Twentieth century history

In 1902, the English pediatrician George Still described a condition analogous to ADHD. He regarded it as innate and not caused by the environment.

The 1918–1919 influenza pandemic left many survivors with encephalitis, affecting their neurological functions. Some of these exhibited immediate behavioural problems which correspond to ADD. This caused many to believe that the condition was the result of injury rather than genetics.

In 1937, a group of children in an institution with behavioral problems were treated with amphetamine drugs for the first time, resulting in behavioral changes appreciated as 'improvements' by caretakers. However, treatment with stimulants was not widely used until the late 1950s.

In 1957, the new stimulant Methylphenidate (Ritalin) became available.

By the 1950s and 1960s, researchers changed the terminology from Minimal Brain Damage to Minimal Brain Dysfunction. This followed observations that the condition existed without any objectively observed pathological disorder or known injury.

The "Hyperactive Child Syndrome" was first described in the 1960s, and was also regarded as not caused by injury. By the late 1960s and 1970s, hyperactivity had caught hold as a popular term, although MBD was also still used professionally.

In the early 1970s an erroneous newspaper article, which is still often cited, inflated the prescribing rate of medication by a factor of 10, influencing some to avoid treatment with stimulants.

In 1973 Dr Ben F. Feingold, once a Professor of Allergy in San Francisco, claimed that hyperactivity was increasing in proportion to the level of food additives, and proposed a specific diet believing that it would help 50% of hyperactive children. The popularity of the claim caused an American Congressional Commission to investigate additives and encourage research.

Most carefully controlled studies showed that only 5% of ADD children showed behavioral effects from their diet (but this was obviously an important finding for that 5%), but some have shown a figure of 60%. One study tested the 50% who claimed to be helped by diet, finding that 10% showed behavioral changes from food triggers.

The Feingold diet excluded cola drinks, chocolate, preservatives and flavour additives, as well as salicylates that occur naturally in fruit such as tomatoes, strawberries, pineapples and oranges. However pineapple juice was suggested as a "safe" drink.

Professional dieticians exclude and re-introduce food groups on a more controlled basis to identify triggers.

In the early 1970s, the 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.

The name attention deficit disorder (ADD) was first introduced in DSM-III, the 1980 edition.

The early 1980s saw the vitamin B6 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. It is claimed that no reputable research has appeared to support any of these claims, except in cases of malnutrition.

In the mid-1980s, Helen Irlen from California took out a patent on certain tints for lenses to help those with reading problems associated with Scotopic Sensitivity Syndrome.

In the late 1980s, 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. They were very effective at the time in scaring people away from treatment with stimulants.

In 1994, DSM-IV described three groupings within ADHD, which can be simplified as: mainly inattentive; mainly hyperactive-impulsive; and both in combination.

Incidence

According to the 2000 edition of DSM-IV-TR, ADHD affects three to seven percent of all children in the U.S. According to 2002 data from the CDC's annual National Health Interview Survey, released in 2004, nearly 4 million children younger than 18 in the United States had been diagnosed with attention deficit hyperactivity disorder (ADHD). However, rates of diagnosis vary widely even within the U.S. In some school districts as many as 60% of all children have been diagnosed with ADHD.

The 2002 data indicated that twice as many boys were diagnosed with ADHD as girls (10% vs. 4%). The causes of this gender disparity are unknown. Some experts theorize that ADHD is underdiagnosed in girls, since their symptoms tend to be less dramatic than those in boys and thus draw less attention from parents and teachers.

Today ADHD is considered by some to be a problem all over the industrialized world, although in no other country are children diagnosed with this disorder as often as in the United States. Critics contend this is primarily a result of pharmaceutical industry marketing, essentially designed to increase sales globally.

The variation in the rates of diagnosis and in estimates of the rate of prevalence raises numerous issues. In fact, almost everything about ADHD has been the subject of intense debate, as discussed later in this article. This debate led the NIH to develop a Consensus Statement in 1998, a link to which is provided in the External Links section below.

ADHD often continues into adolescence and adulthood, according to proponents of the diagnostic label, and can cause a lifetime of frustrated dreams and emotional pain. However, children diagnosed with ADHD often go on to live normal lives, and wonder why their parents and schools felt the need to medicate them. Many complain of having needlessly suffered from the psychological trauma of the diagnosis, social stigmatization, and adverse effects of the drugs. A grave concern often cited by critics is their concern that prescribed medications may cause persistent substance abuse problems. Others have written of how diagnosis and treatment improved their lives.

Evidence for ADHD as an organic phenomenon

Brain imaging research using magnetic resonance imaging (MRI) has shown that differences exist between the brains of children with and without ADHD, though these differences have not been shown in any way to be pathological in nature. Many scientists consider these results to be significant in themselves, but in addition PET studies have shown there might be a link between a person's ability to pay continued attention to external directives and the use of glucose - the body's major fuel - in the brain. In adults diagnosed with ADHD, the brain areas that control attention use less glucose and appear to be less active, suggesting that a lower level of activity in some parts of the brain may cause inattention (Zametkin et al.). However, there is no evidence that this low level of glucose in fact causes the low level of attention to external direction; it could in fact be no more than an indicator for low attention, or in the alternative, superior self-direction.

Perhaps more interesting are the results of some studies using SPECT (Single Photon Emission Computed Tomography). One study (Lou et al. in Arch. Neurol. 46(1989) 48-52) found people labeled as ADHD have reduced blood circulation in the striatum. But even more significant may be the discovery that people with ADHD seem to have a significantly higher concentration of dopamine transporters in the striatum (Dougherty et al. in Lancet 354 (1999) 2132-2133; Dresel et al. in Eur.J.Nucl.Med. 25 (1998) 31-39). Researchers have also shown that individuals labeled as either bipolar or ADHD often have varient dopamine receptor alleles. Researchers have reported, for example, that DRD4 7 repeat alleles appear more frequently in certain aboriginal cultures with low population densities such as the Amazon, whereas DRD4 2 repeat alleles are expecially common in higher population density regions, including the Orient.

It has been known for some decades that head injuries can cause a person to experience and display ADHD-like symptoms.

Is ADHD inherited?

According to the NIMH Q&A cited below:

Research shows that ADHD tends to run in families, so there are likely to be genetic influences. Children who have ADHD usually have at least one close relative who also has ADHD. And at least one-third of all fathers who had ADHD in their youth have children with ADHD. Even more convincing of a possible genetic link is that when one twin of an identical twin pair has the disorder, the other is likely to have it too.

There is increasing evidence that variants in the gene for the dopamine transporter are related to the development of ADHD (Roman et al., 2004, Am J Pharmacogenomics 4:83-92.). This makes sense, as alterations in dopamine related sites in the brain have been identified in those diagnosed with ADHD and because dopamine transporter blockers are used to treat the disorder. However, it has been noted that although as many as 20 genes have been identified to be related to ADHD, none of them account for more than 5% of ADHD cases (Shastry, 2004, Neurochem Int 44:469-474.). This strongly suggests that not only is there no one gene that causes ADHD, it is unlikely that genetic factors are the major source of ADHD.

Other possible causes

ADHD is broadly defined and pervasive, and the symptoms attributed to ADHD likely have a variety of different causes. The initial triggers could include genetic vulnerabilities, viral or bacterial infections, brain injury, or nutritional deficits. There has been a surge in alternative approaches to ADHD, but these have been vigorously disputed, paticularly by the pharmaceutical industry. Dietary factors have in particular been touted as important, but research primarily funded by the industry has obfuscated support for these claims. It has been established conclusively that there are children that are sensitive to dyes and other food additives, sugar, caffeine, etc. (Jacobson and Schardt, 1999, Diet, ADHD & Behavior, Center for Science in the Public Interest, Washington, DC).

The finding of another probable cause stemmed from the observation that children of women who smoked during pregnancy are more likely to be diagnosed with ADHD (Kotimaa et al., 2003, J Am Acad Child Adol Psychiatry 42, 826-833). Given that nicotine is known to cause hypoxia (too little oxygen) in the uterus, and that hypoxia causes brain damage, smoking during pregnancy is likely an important contributing factor leading to ADHD. It may even help explain in part the increase in ADHD diagnoses, as the number of women smokers has increased. However, there are not nearly enough women smoking during pregnancy to account for all the ADHD diagnoses. What then are the other causes?

A number of different lines of research may be converging on an answer, or at least part of the answer. First, neuroscientists have determined that the dopamine system does appear to be central to the symptoms of the diagnosis, and certain changes in this system are consistently seen in those labeled as having ADHD. Second, certain essential fatty acids, omega-3 fatty acids, have received increasing attention from nutrition researchers as being essential for healthy brain development. This family of compounds has been directly tied into function of the dopamine system, and appears to be of critical importance in formation and maintenance of these systems. Third, clinical nutritionists have noted that ADHD labeled children are often deficient in omega-3 fatty acids, and that supplementation with various fatty acids may reduce some of the symptoms.

Is there really a connection between omega-3 fatty acids and ADHD? The research supporting such a connection was conducted by scientists in three very different areas who do not ordinarily communicate with each other. This means no one has specifically studied the possibility. However, the findings in each area are very suggestive. If the connection between omega-3 fatty acids is true, then dietary supplementation could be an effective prevention for the disorder, and could be a less costly alternative treatment, with fewer adverse effects, and would ultimately address the root problem, unlike current psychotropic drug treatments.

The nutritional data has been well summarized in a review article (Burgess et al., 2000, Am J Clin Nutr 71:327-330). Children with ADHD have lower levels of key fatty acids. In fact, one study found that the lower the levels, the worse the symptoms. The possibility that fatty acid deficiency is a trigger for ADHD is especially plausible as nutrition scientists have recently demonstrated that the American diet is extremely deficient in omega-3 fatty acids. At the same time, ADHD diagnoses are rapidly increasing. More support for this idea comes from findings that breast-fed children have much lower levels of ADHD, and that until quite recently, infant formula contained NO omega-3 fatty acids. These findings are only correlational, and do not prove a causal connection.

Initial studies with supplementation with various fatty acids found improved cognitive function, visual acuity, and reduction of at least some of the symptoms of ADHD. These findings are similar to those in which improved cognitive function and increased IQ are seen in breastfed children, who get more fatty acids from their mother’s milk than do formula-fed infants. The data from these studies are promising, but as yet inconsistent. Why did only some of the studies see an effect, and why were only some symptoms improved? These questions cannot be answered unless one knows about the effects of these fatty acids on the dopamine system, and the economic realities regarding who is funding studies attempting to debunk the correlation.

Making an adult lab rat deficient in omega-3 fatty acids results in significant metabolic changes, in the number of dopamine receptors and the amounts of dopamine in different parts of the brain responsible for learning, memory, and attention. Not surprisingly, adding n-3 fatty acids reversed these effects. More interesting studies have looked at developmental effects. If female rats are fed a diet deficient in n-3 fatty acids and then become pregnant, their offspring show marked changes in the dopamine areas of the brain, which look like those seen in ADHD-labeled children, and in the spontaneously hyperactive rat (Acar et al., 2003, Neurosci Res 45:375-382). The pups were also hyperactive. Supplementation of the female rats’ diet either during pregnancy or while nursing prevented this from happening. However, supplementing the pups’ diet after weaning only partially reversed the effects. This means that supplementation will only be partially effective as a treatment. Changing the diet of pregnant women and their infants and toddlers will be necessary to maximize the effectiveness of n-3 fatty acids in preventing ADHD symptoms.

There is also new evidence that brief pauses in breathing (apnea) during infancy may be a cause of ADHD. Dr. Glenda Keating of Emory University presented data at the Society for Neuroscience annual meeting in October 2004, 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. (ScienceDaily)

Positive aspects

Though ADHD is classified as a serious disorder, many people have a different perspective. Some see it as a gift. In his book ADD - Attention Deficit Disorder (1997), Thom Hartmann developed the idea that people having ADHD symptoms may have simply inherited a collection of genes that were selected for when hunting was particularly important. This idea is the basis of another of his works, The Edison Gene: ADHD and the Gift of the Hunter Child (2003).

People who believe that ADHD is a gift find hints of ADHD in the lives of many famous people in history. Though such post mortem diagnosis is questionable, it is intriguing to ponder the evidence that people such as Thomas Edison might have been diagnosed as having ADHD if the current DSM criteria had been developed long ago. Other historical figures who have been proposed as ADHD candidates include: Hans Christian Andersen, Ludwig van Beethoven, Winston Spencer Churchill, Walt Disney, Benjamin Franklin, Robert and John F. Kennedy, Theodore Roosevelt, Jules Verne, Woodrow Wilson and the Wright brothers.

Some contemporary ADHD candidates have also been proposed, including George W. Bush, Whoopi Goldberg and Dustin Hoffman.

To see ADHD as a gift may seem somewhat problematic to anxious parents, and especially to the pharmaceutical industry, but it is at least a perspective that should be kept in mind.

Psychological testing for ADHD

Psychological testing for ADHD symptoms generally consists of obtaining multiple types of assessments. These usually include a clinical interview reviewing the DSM-IV criteria for ADHD diagnosis. The interview also needs to rule out as much as possible other types of syndromes which can cause attention problems, such as depression, anxiety, and psychosis. External social and environmental influences are given scant attention, as internal disorders are an assumption of the standard diagnostic protocols for ADHD. Rating scales can be administered which provide measurement of the person's own view of their symptoms, as well as the views of parents, teachers, and significant others. Finally, computerized tests of attention can be helpful in providing a further independent assessment. These different assessments may not be consistent, but do provide a view of the person's difficulties. Subjectivity of the analysis can be compounded by the fact that physicians generally need not order psychological testing in order to make the diagnosis of ADHD, but many doctors use this kind of assessment to avoid over-diagnosis and treatment. The process of obtaining referals for such assessments is being pushed vigorously by the pharmaceutical industry, in the guise of the President's New Freedom Commission on Mental Health

Neurometrics, PET scans, or SPECT scans have been used for a more objective diagnosis. These are not usually suitable for very young children.

Attention deficit disorder also is diagnosed in adults, and an assessment for this is also needed.

Skepticism towards ADHD as a diagnosis

It should be noted that many, if not most, creative individuals exhibit the characteristics of ADD, or ADHD, by virtue merely of their naturally divergent paths of thinking. As in the case of many, if not all, others who exhibit such characteristics, there is no cause to suppose that it is their constitution, rather than that of society generally, that is the condition needing to be rectified.

Critics have complained that the ADHD diagnostic criteria are sufficiently general or vague to allow virtually any child with persistent unwanted behaviors to be classified as having ADHD of one type or another. Such a wide diagnostic net can also be seen as diluting the perceived significance of the disorder. Diagnostic questionnaires are often subject to copyright restrictions, preventing a wider awareness of their specificity.

Many people, including a growing number of critics, have wondered why the number of children diagnosed with ADHD in the U.S. and UK has grown so dramatically over a short period of time. It has often been suggested that the causes of the apparent ADHD epidemic lie in cultural patterns that variously encourage or sanction the use of drugs as a simple and expeditious cure for complex problems that may stem primarily from social and environmental triggers rather than any innate disorder. Some critics assert that many children are diagnosed with ADHD and put on drugs as a substitute for parental attention, whereas many parents of ADHD children assert that the associated demand for attention goes beyond what can be humanly provided, causing massive disruption to other individuals and relationships, as well as to environments with dysfunctionally structured relationships such as are manifest in many classrooms. This criticism also includes the use of prescription drugs as a substitute for parental duties such as communication and supervision.

Some schools have required 'problem' pupils to undergo ADHD diagnosis (and treatment if diagnosed), which has caused protests. Some parents are alleged to have been threated with, or subjected to, child abuse charges for not allowing their children to be treated with psychotropic drugs. Some critics have suggested that the ADHD label should be abolished altogether.

Douglas Rushkoff, among other critics of ADHD diagnosis, suggest that the disorder may be primarily the result of cultural conditions to which children and adults alike are subjected. Primary among these is the omnipresence and exploitive qualities of advertising. In the time that ADHD has arisen as the epidemic it is often portrayed as, advertisement has become virtually unavoidable, and advertisements utilize much more sophisticated methods of deception. Some suggest that people (children, especially) are aware of this attempt at pervasive trickery, whether consciously or subconsciously, and react by avoiding extended attention in order to avoid being deceived. Naturally, this self-defense reaction, when carried over to school and home, presents obvious problems. From this point of view, prescribing drugs is effectively only to alleviate symptoms, but entirely avoids the cause.

Thom Hartmann, among others, takes an approach from biological evolution to argue that ADHD is not a disorder, but an expression of biodiversity. From an evolutionary point of view, it is quite acceptable that humans—like other animals—differ in their biology and pass on their traits from generation to generation. It has not yet been proven wrong that ADHD symptoms indeed could be a product of advantageous human evolutionary adaptations, and therefore not necessarily a disability, disorder, condition or mental illness.

Another source of skeptism towards making the diagnosis of "ADHD or not ADHD" may arise from the rising diagnosis of subclinical forms of ADHD. So called 'Shadow-syndromes' or 'sub-syndromes' stand for weaker forms of ADHD and are described in various degrees by John J. Ratey and Catherine Johnson on their book Shadow Syndromes: The Mild Forms of Major Mental Disorders That Sabotage Us.

Treatment

There are many options available to treat people diagnosed with ADHD. These options include a variety of medications, behavior-changing therapies, and educational interventions.

The first-line medications used to treat ADHD are stimulants, including Ritalin (a trade name for methylphenidate, marketed by Novartis), Adderall/amphetamine (Adderall is a trade name for a mixture of dextroamphetamine and laevoamphetamine salts, marketed by Shire Pharmaceuticals), Desoxyn/methamphetamine (Desoxyn is a trade name for methamphetamine, marketed by Ovation Pharma) and Dexedrine/Dextroamphetamine. Another stimulant Cylert/Pemoline was 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 perscribe Cylert, it can no longer be considered a first-line medicine. 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.

Second-line medications include less-powerful stimulants such as benzphetamine and Provigil/modafinil, although research as to the efficacy of these drugs is not complete.

Data from 1995 show that physicians treating children and adolescents wrote six million prescriptions for stimulants. Of all the drugs used to treat psychiatric disorders in children, stimulant medications are the most well-studied. However, to date there are no good long-term studies dealing with stimulants in children, and concerns exist pertaining to the ethics of conducting experiments involving children. A 1998 Consensus Development Conference on ADHD sponsored by the National Institutes of Health and a recent, comprehensive, scientific report confirmed many earlier studies showing that short-term use of stimulants is safe and effective for children with ADHD. This says nothing for the growing number of children who are on stimulants for years at a time. Some non-stimulant medications are now becoming available to treat ADHD such as Strattera (atomoxetine HCl), a selective norepinephrine reuptake inhibitor.

In December 1999, NIMH released the results of a study of nearly 600 elementary school children, ages seven-to-nine, which evaluated the safety and relative effectiveness of the leading treatments for ADHD for a period up to fourteen months. The results indicate that the use of stimulants alone is more effective than behavioral therapies in controlling the core symptoms of ADHD - inattention, hyperactivity/impulsiveness, and aggression. In other areas of functioning, such as anxiety symptoms, academic performance, and social skills, the combination of stimulant use with intensive behavioral therapies was consistently more effective. (Of note, families and teachers reported somewhat higher levels of satisfaction for those treatments that included the behavioral therapy components.) NIMH researchers will continue to track these children into adolescence to evaluate the long-term outcomes of these treatments, and ongoing reports will be published. This study has been severely criticized, as it was not double-blind and the sponsors failed to provide a control group.

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. This has a very high success rate, but is not widely used, or covered by insurance. Many professionals consider the treatment promising, but state that there is not yet sufficient evidence that it works after the immediate treatment is complete.

Maintaining a schedule routine, and a well structured work environment often helps children with ADHD stay focused and on task.

Other ADHD-related controversies

There are other controversies intersecting with ADHD, to do with:

The controversies attract popular attention including the mass media. Media critics in the scientific community say that, despite often employing science reporters, such reporters have inherent inabilities to accurately report on scientific papers without sensationalising them, using exaggeration, undue emphasis of aspects, taking aspects out of context, and publishing point-of-view features within news contexts. They also say the mass media fails to identify procedural lapses in studies allowing dubious conclusions to be publicized. Such lapses include: lack of peer review, small sample sizes, lack of published error ranges, filtering of results, lack of control groups and lack of use of double-blind techniques or placebos. Examples of cited of such media misrepresentation include the University of Washington study (see below), which was widely reported as proving that television causes ADHD, despite disclaimers within the published study apparently seeking to avoid this very headline.

  • The Norwegian scientist Dr. Karl Ludwig Reichelt claims that peptides from casein (milk-protein) and gluten (grain-protein) worsen the symptoms in many ADHD-patients. Extensive testing of ADHD-patients is taking place in Norway, and diet has astonishing effects for many of them. Although good result are achieved in Norway, the peptide-theory is discarded by the scientific community.

Miscellaneous

Fictious characters with ADHD include Animal.

References

  • 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.)
  • Hartmann, Thom. (1998) Healing ADD: Simple Exercises That Will Change Your Daily Life. Underwood-Miller (1st ed.) ISBN 1887424377 (Uses Neurolinguistic Programming techniques)

External links

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