This Wiki page is edited by participants of the Cognitive and Learning Disabilities Accessibility Task Force. It does not necessarily represent consensus and it may have incorrect information or information that is not supported by other Task Force participants, WAI, or W3C. It may also have some very useful information.
- 1 Description
- 2 Cognitive functions
- 3 Symptoms
- 4 Challenges
- 5 Some persona with use case that address key challenges
- 6 How they use the web and ICT to include: Email, apps, voice systems, IM
- 7 How people with cognitive disabilities use optimized content and special pages
- 8 Characteristics of content optimized for this group
- 9 Specific technologies (reference section bellow and how they use it differently)
- 10 Summary Existing research and guidelines
- 11 Extent to which current needs are met
- 12 Potentials and possibilities
- 13 Prevalence
- 14 References to research.
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting both children and adults. It is characterized by some persistent (lasting at least 6 months) symptoms of hyperactivity, impulsivity, and/or inattention that significantly impacts daily life or typical development. The symptoms frequently occur in more than one environment (e.g. in work and at home) and they must not be appropriate for the age of the individual. The symptoms should also cause social, educational or work related issues (American Psychiatric Association, 2013).
Review of the available literature suggests that ADHD is not viewed as single impairment / disease entity, but people with ADHD can be considered as a heterogeneous group of individuals defined by a series of behavioural symptoms. The symptoms presented vary in type and intensity between individuals with ADHD and may vary in type and intensity with time for a given individual.
Note: To-do to separate the Comorbidity items
No single cognitive impairment characterises people with ADHD (American Psychiatric Association, 2013). Cognitive impairments, although secondary, feature in the diagnosis of ADHD (American Psychiatric Association, 2013)and are vital in determining the learning and cognitive needs of people with ADHD.
Studies have suggested that children with ADHD exhibit multiple deficits in working memory related to spatial storage and spatial executive functioning that are independent of any language learning disorders presented by the same individual (Martinussen, et al., 2005). It has also been suggested that dysfunctional neurological parallel processing pathways are a potential partial explanation of executive dysfunction association with ADHD, but further research on cognition from a neurophysiological and developmental point of view are required to confirm this (Castellanos, et al., 2006).
Cognitive impairments associated with ADHD include (Nigg, 2009):
- Issues with executive functioning
- Reading learning disabilities
- Math disabilities
- Handwriting disabilities
- Non-verbal learning disabilities
- Diminished visual processing speeds not related to inattention (Weiler, et al., 2002)
- Developmental coordination disorder / motor clumsiness. Motor clumsiness may be less prevalent in older children (9 years and older), teenagers and adults with ADHD (Meyer & Sagvolden, 2006)
Context dependent cognitive effects associated with ADHD include issues with (Nigg, 2009):
- Slow careful behavior
- Fast accurate behavior
- Rapid decision making
- Planning and short term recall
- Reward cues
- Time estimation
It is unclear if any of these context dependent cognitive effects are unique to ADHD. However, evidence suggests they are not explained by co-occurring problems and, in most instances, they are more clearly associated with ADHD (the issue being more pronounced) than with other disorders exhibiting the same issue (Willcutt, et al., 2008).
Comorbidity with learning disabilities is common in people with ADHD. The literature reviewed shows a wide variance of the incidence of people with ADHD that also present with learning disabilities of between 20 and 60% (Czamara, et al., 2013). This highly variable overlap has been previously attributed to inconsistencies in the definition of learning disabilities and a general over identification of learning disabilities (Semrud-Clikeman, et al., 1992). However, comorbidity with reading disorder (Germanò, et al., 2010), dyslexia and dyspraxia (Pauc, 2005) and dyscalculia (Lindsay, et al., 2001)have all been reported, although the underlying functional processes remain unclear (Czamara, et al., 2013).
Comorbidity with behavioral disabilities (such as oppositional defiant disorder and developmental coordination disorder) has been shown to be extremely high (>70%) amongst young children (Kadesjö & Gillberg, 2001) suggesting that ADHD without comorbidity is atypical in children with ADHD.
The most commonly used diagnosis of ADHD follows the guidelines outlined by the American Psychiatric Association (2013) and will be followed here. Three presentations (formerly called subtypes) of ADHD are recognised:
- Predominantly Inattentive ADHD
- Predominantly Hyperactive-Impulsive ADHD
- Combined ADHD
Predominantly Inattentive ADHD - symptoms
Symptoms associated with Predominantly Inattentive ADHD include:
- Failing to pay close attention to detail or making careless mistakes
- Having difficulty sustaining attention
- Not appearing to listen
- Struggling to follow instructions to completion
- Difficulty with organization
- Avoiding or disliking tasks requiring a lot of thinking
- Losing things
- Being easily distracted
- Being forgetful in daily activities
Predominantly Hyperactive-Impulsive ADHD – symptoms
Symptoms associated with Predominantly Hyperactive-Impulsive ADHD include:
- Fidgeting with hands or feet or squirming in chairs
- Having difficulty remaining seated
- Running around or climbing excessively in children; extreme restlessness in adults
- Difficulty engaging in activities quietly
- Acting as if driven by a motor; adults will often feel inside like they were driven by a motor
- Talking excessively
- Calling out answers before questions have been completed
- Difficulty in waiting or in taking turns
- Interrupting or intruding upon others
Diagnosis of ADHD
To be diagnosed with ADHD using the above symptoms, a child should exhibit at least 6 of the symptoms of the disorder and late teens and adults at least 5 symptoms. The ADHD presentation exhibited depends on the predominance of the symptoms being mostly inattentive symptoms, mostly hyperactive-impulsive symptoms or a relatively equal mix of symptom type resulting in Predominantly Inattentive ADHD, Predominantly Hyperactive-Impulsive ADHD or Combined ADHD respectively.
ADHD presentations can be subdivided into mild, moderate or severe depending on both the number of symptoms exhibited and the impact the symptoms have on the individual’s daily life. Presentations are not fixed and can change throughout the lifetime of a person with ADHD as can the severity of the individual symptoms.
To do: challenges section should reference ICT. In addition, comorbidity would need to be separated out.
Challenges for people with ADHD are dependent on their presentation of ADHD and the symptoms associated with the individual. Due to the high incidence of comorbidity with learning disabilities, it is difficult to identify challenges that are unique to people with ADHD. As noted above, the number and severity of the symptoms associated with a particular presentation of ADHD can vary with time (Centers for Disease Control and Prevention, 2014a). A result of this is that the challenges for a person with ADHD can also vary in type and intensity as the individual ages. In general terms, the challenges associated with ADHD highlighted by Nigg (2009)include:
- Issues with speed and attention to detail: Tasks are often completed with excessive speed (Hyperactivity-impulsivity) or excessively slowly due to lack of interest (Inattentive). In both cases these behaviors are associated with inaccuracy.
- Issues with Rapid decision making: The ability to interrupt their responses often results in answers being blurted out and talking out of turn during meetings.
- Executive Functioning and Working Memory: The inability to follow instructions to their conclusion is common, especially when the instructions are presented in list form. This challenge can also extend to tasks that involve ordered steps such as complex arithmetical operations or equation solving. Issues with working memory are often exhibited as forgetfulness.
- Social Issues: In addition to difficulty interpreting social subtexts, momentary lapses in attention is common. This can often result in missing important details if they are not repeated. Children with ADHD often have difficulty estimating the value of social contact, consistently underrating the rewards associated with social contact when compared to control groups (Demurie, et al., 2011).
- Self-worth Issues: Anecdotal evidence form teachers and parents suggest that children with ADHD exhibit low self-esteem and lack of confidence. This may be a result of peer rejection due to actions by a person with ADHD being considered inappropriate. Self-worth issues can result in tasks being abandoned earlier than would be the case with a control group and a perceived lack of commitment to group and/or team activities.
Some persona with use case that address key challenges
To do: Develop persona and scenarios. When dealing with broad spectrum disorders that exhibit multiple symptoms (ADHD, ASD) it may be better to break the step challenges into more "bite-sized" chunks that exhibit particular issues that people with these disorder encounter - similar to the last scenario described.
To do: Find sites / tasks that present more of a significant challenge with respect to people with ADHD and replace the existing senarios. Too many "No challange" steps fail to capture the issues properly.
Booking a festival ticket online
Scenario A: “Paula” has been diagnosed with ADHD presenting as predominantly inattentive. She is 17 years old with low self-esteem and is easily discouraged. Her attention to detail is poor and her attention span is low. She has a tendency to forget things quickly and give up in frustration. She has both younger and older siblings who do not present with ADHD and she does not take medication. She is trying to book and pay for a single day ticket for the first day of a four day music festival - the Hatfield House Chamber Music Festival.
|Search for the festival||Some care must be taken when searching for the festival information as it is not found on any of the major ticket sites (e.g. Ticketmaster). However, search engines are robust with respect to spelling and typing errors. The auto suggestion returns meaningful results.|
|Select the link to the festival.||No challenges. The main link takes you to the home page where a link to purchasing tickets is prominently displayed. All of the other pages on the site have prominent links to the ticket purchasing section.|
|Select the purchase option for the first day.||No challenges. The page is clearly laid out with few distractions. The Buy Tickets button is obvious and the page is both clean and clearly laid out.|
|Select the number of tickets required.||No challenges. Most of the form is pre-filled and the completion step is based on a simple pull-down menu. The default is zero and a meaningful error is returned if this is not changed.|
|Add the purchase to the basket||No challenges. The button is clearly displayed and positioned within the logical flow of the page.|
|Click on Checkout.||No challenges. The page has a standard layout and is color coded.|
|Click on Pay Now||This step may present minor difficulty as a number of options are presented (Pay Now, Log in / Register, Add More Tickets)|
|Fill in address details.||This may prove difficult as the address details are used as to pre-populate the billing address at a later stage. The only error correction is a check on the validity of the postcode and a confirmation of the e-mail address. The required fields are clearly marked.|
|Select the Payment Method||No challenges.|
|Enter Card Details.||This step presents challenges as the information must be entered accurately and the error handling returns somewhat cryptic responses. In addition, some of the pop-up messages do not receive focus in the Chrome browser and are easily missed. This may cause Paula to give up at this point.|
|Confirm payment details||No challenges.|
Ordering groceries online for home delivery
Scenario B: “Ian” is 34 and has been diagnosed with ADHD presenting predominantly Hyperactive-Impulsive. He lives alone, but his mother is planning to visit. He needs to order his grocery shopping online from ASDA using a prepared shopping list that was created for his previous visit. The list is a physical list and not saved on the site. Ian will have to register on the site. The delivery times are restricted and he needs to ensure that he is available to take delivery of the groceries. The delivery should take place on the evening of the 4th of October.
|Navigate to ASDA site.||No challenges.|
|Select ASDA Groceries.||The ASDA Groceries button is relatively prominent and there is a great deal of advertisements and banners. This may prove distracting to Ian and cause him to lose focus on the task at hand.|
|Enter postcode.||No challenges. Any errors in entering the code are handled by the system so the code will be valid.|
|Click Continue.||No challenges.|
|Select Title.||No challenges.|
|Enter First and Last Name.||No challenges.|
|Enter and confirm e-mail address.||No challenges.|
|Select “No, I’m shopping from Home”||No challenges.|
|Select Address||No challenges. This is selected from a pull-down populated based on the post code. This eliminates typing errors.|
|Add Address nickname.||No challenges.|
|Select Property Type.||No challenges.|
|Enter Phone number.||No challenges. Basic error checking in place.|
|Accept Terms and Conditions.||No challenges.|
|Select “I am over 18 years old||No challenges.|
|Click Register||No challenges.|
|Click Choose a slot.||No challenges. The action required is clearly presented and explained.|
|Click on the 4th of October on the calendar||No challenges.|
|Select Continue Shopping.||No challenges.|
|Select Fresh Food||No challenges.|
|Select Meat : Chicken, Duck and Game : Whole Chickens||No challenges.|
|Select Butcher's Selection Whole Chicken||No challenges. The choices are clearly laid out and there is no irrelevant information.|
|Click Add||No challenges.|
|Select Fresh Food||No challenges.|
|Select Fruit, Vegetables & Flowers : Potatoes : White Potatoes||No challenges.|
|Select ASDA White Potatoes||No challenges.|
|Click Add||No challenges.|
|Select Fruit, Vegetables & Flowers : Vegetables : Carrots and Root Veg||No challenges.|
|Select ASDA Sliced Carrots||No challenges. The choices are clearly laid out and there is no irrelevant information|
|Click Add||No challenges.|
|Click Checkout||No challenges.|
|Select Billing address||No challenges – based on registration details|
|Select Card Type||No challenges – select from pull down|
|Enter Card Details||This may provide some degree of challenge as the details must be accurate. However, each step is error checked which mitigates the risk somewhat.|
|Select Save and Continue||No challenge.|
|Click confirm order and authorise payment||No challenge.|
|A confirmation e-mail will be sent to Ian. He can use to set up a reminder of the delivery date and time in a calendar.|
This site presented Ian with few challenges due to the error checking at individual key steps; it is easy to focus on the task at hand and the fact that the activities can be achieved rapidly.
Researching and presenting a school project
Scenario C: “Anne” is a 13 year old school student who has been diagnosed with ADHD presenting as Combined. She needs to conduct an online research project on the extinction of the dinosaurs. She is expected to consult multiple sources but these need not be academic papers to enable her to prepare a 15 minute PowerPoint presentation that will be delivered deliver to her class. She has one month to prepare.
[Unlike the pervious scenarios, this scenario does not concentrate on the individual processing steps but on the overall effect of the presentation of information.]
|Search for information online||No challenges. Search engines are robust with respect to spelling and typing errors and the auto suggest returns useful results.|
|Select sites for investigation.||This step presents a significant challenge to Anne due to information overload.|
[As part of this scenario, 4 sites will be consulted and their assessed from the Anna’s point of view as a person with ADHD]
|Consult about.com Dinosaur extinction http://dinosaurs.about.com/od/dinosaurextinction/||This site presents significant challenges to staying focused and relating different parts of the article due to the number of links to material that is not related to the topic in question and a series of advertisements that distract from the flow of information. Although the sub-pages are clearly defined with short summaries, they are not presented in a logical order.|
|Consult BBC NATURE Cretaceous-Tertiary mass extinction page http://www.bbc.co.uk/nature/extinction_events/Cretaceous%E2%80%93Tertiary_extinction_event||This site presents few challenges as the information flows logically and is clearly laid out. The content is also presented in a less passive manner than is usual. All of the links on the page are relevant. The linked pages present a challenge with respect to navigation as they are independent articles and there is no bread crumb trail. The only way to retrace steps is through the browser back button.|
|Consult Wikipedia - Cretaceous–Paleogene extinction event http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event||This site presents challenges due to the volume of information presented and the density of the text. Maintaining focus may prove challenging.|
|Consult Smithsonian National Museum of Natural History – Dinosaurs Why did they go extinct? http://paleobiology.si.edu/dinosaurs/info/everything/why.htm||This site presents significant challenges due to the volume of information and the way that the text is structured. The site is designed to be navigated sequentially which may prove a challenge to Anna and the lack of a bread crumb trail and page titles may make orientation within the site difficult.|
How they use the web and ICT to include: Email, apps, voice systems, IM
There is no apparent body of evidence that people with ADHD use the web in a particular way. The prevalence of other learning disabilities presenting with ADHD makes determinations of special usage activities that are unique to ADHD problematic. However, anecdotal evidence (Smith & Segal, n.d.), (Tartakovsky, 2013) suggests that the use of recurring e-mails tasks and voice mail as well as automated reminders based on timers are used to help people with ADHD to stay focused and “on task”.
How people with cognitive disabilities use optimized content and special pages
There is no apparent body of evidence of special pages or content specifically optimized to support people with ADHD.
Characteristics of content optimized for this group
Before content can be optimized to support users with ADHD further research is required into the challenges presented by ADHD that are not a result of other learning disabilities.
Specific technologies (reference section bellow and how they use it differently)
There are no specific assistive technologies for people with ADHD. There are, however several iPhone and Android Apps that have proved useful to people with ADHD (Watson, 2014). Anecdotal evidence (Cummins, 2014), (Duffy, n.d.) suggests that tools and assistive technologies that have proved useful for adults students with ADHD include:
- Digital pens (such as Livescribe) that help with note taking when lack of concentration may lead to main points being missed.
- Word prediction software (e.g. Co:Writer),
- Screen readers
- Mind mapping software
- Speech recognition software
- Talking calculators (MathPad / Math talk), especially if they have timers/alarms to help students progress steadily.
- Timers and to-do lists
- Using e-mail and voice mail as reminders
All of the above tools / techniques are designed to provide support with issues around accuracy and concentration that are common to people with ADHD.
Summary Existing research and guidelines
To do: Expand on the bias in existing research. Expand on the difference in heritability between children and adults. Expand the Pathophysiology subsection. Expand the management section to cover medication controvesy and geographic varations. Expand guildines to include interface design.
ADHD was first clearly described by George Still in 1902 but it may have been partially recognized as early as the late 18th Century (Wikipedia, 2014). The symptoms associated with ADHD are listed above and the current diagnosis of the condition is defined in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) published by the American Psychiatric Association (American Psychiatric Association, 2013). Hyperkinetic disorders as defined by the World Health Organization (World Health Organisation, 2014) exhibit similar symptoms to ADHD and, for the purposes of providing ICT support, they can be considered along with ADHD.
Causes of ADHD
The cause of the majority of ADHD cases is unclear and a number of factors may be involved in each case. Current research suggests that genetic factors are important in the development of ADHD (Centers for Disease Control and Prevention, 2014c). ADHD appears to have a very high heritability, independent of geographic location, associated with the Latrophilin 3 gene (LPHN3) (Arcos-Burgos, et al., 2010). ADHD is commonly inherited from one or both parents and children with siblings are 3 to four times more likely to develop ADHD than siblings of children without the disorder. Genetic factors are also thought to determine if the condition persists into adulthood (Franke, et al., 2012). Studies of the heritability of ADHD in adult populations are much less common than studies in children.
In cases where heredity does not seem to be a factor, difficulties during pregnancy, prenatal exposure to alcohol and tobacco, premature delivery, significantly low birth weight, excessively high body lead levels, and postnatal injury to the prefrontal regions of the brain have all been found to contribute to the risk for ADHD to varying degree (National Resource Center on ADHD, n.d.). In addition, exposure to organophosphates my result in symptoms similar to ADHD, but the results are unclear (de Cock, et al., 2012).
It is widely recognised that ADHD is neurodevelopmental disorder associated with functional impairments in some of the neurotransmitter systems of the brain, particularly those involved in the transmission of dopamine and norepinephrine (Wikipedia, 2014).
Children and adolescents with ADHD have brains that are 3-4% smaller than those of a control group. Basic neuroimaging research is being conducted to further delineate the pathophysiology of ADHD, determine diagnostic utility of neuroimaging, and elucidate the physiological effects of treatment. However, the research is currently not definitive enough for the practical application of neuroimaging. (National Resource Center on ADHD, n.d.).
The management of ADHD typically involves counselling, medication or a combination of both. Medication typically involves the use of psychostimulants to boost and balance levels of neurotransmitters present in the brain and antidepressants (Mayo Clinic, n.d.). Significant and varied side effects may be associated with medication programs for ADHD and these side effects may vary as the patient ages (Mayo Clinic, n.d.).
While treatment may reduce the effect of some of the symptoms associated with ADHD, it has not been shown to suppress all of the symptoms (Mayo Clinic, n.d.).
Although there are no specific guidelines produced by a governing body, there are several non-medical ways to help an individual cope with effects of ADHD with respect to ICT. These are listed in the section: Specific technologies (reference section below and how they use it differently).
Extent to which current needs are met
There is no apparent body of evidence to indicate the extent to which current needs are met with respect to ADHD.
Until further research is done to identify how content can best be optimized for people with ADHD, it will be difficult to determine the extent to which the needs of people with ADHD are being met.
Given the high coincidence of learning disabilities and ADHD (Czamara, et al., 2013), it may not be possible to disentangle the needs associated primarily with ADHD on the basis of the disabilities presented and a user centric approach using a series of personas may be more realistic. With further research user needs associated primarily with ADHD may be identified, but these are likely to be general rather than specific in nature due to the relatively high coincidence of learning disabilities and ADHD (Czamara, et al., 2013).
Potentials and possibilities
To do: suggest approaches in gathering evidence of the effectiveness of specific tools and designs using "ground truthing" with people with ADHD.
Issues associated with ADHD that do not have analogous issues associated with other learning disabilities tend to be associated with:
- Working memory
- Rapid response
This suggests that designs beneficial to people with ADHD should emphasize:
- Concise content
- Distraction free layout
- Consistent, simple processing steps
- Robust error correction where forms are involved
Anecdotal evidence (Sinfield, 2014), (Smith & Segal, n.d.) suggests that people with ADHD find visual representations, color coordination and lists easier to process and remember. However, color discrimination may be impaired in people with ADHD (Banaschewski, et al., 2006) so color coordination must be used carefully. These features may prove useful in designing “ADHD friendly” content.
Much of the evidence to date of the effectiveness of assistive technology and design techniques with respect to ADHD is anecdotal. In order to provide robust guidelines for supporting people with ADHD more rigorous, evidence based investigations into which assistive technologies, tools and design techniques prove beneficial to people with ADHD are required.
These investigations need not, however, meet the strict criteria of a clinical trial. Surveying people with ADHD with regard to the assistive technologies and design techniques that they find useful combined with a series of product preference tests may provide insight on the criteria that should be used in recommending how content should be optimized for people with ADHD.
To do: Discuss the varaition in prevalence in terms of geography, culture, gender age and historic factors in more detail.
The prevalence of ADHD worldwide is 5.29% of the population, although there is significant geographical and gender variation with diagnosed incidences of ADHD being lowest in Africa and the Middle East and higher in individuals of 18 years or younger (Polanczyk, et al., 2007). The cause of this variation is unclear and may be a result of different attitudes to reporting and diagnosing the condition rather than any actual variation in the prevalence of ADHD (Bussing, et al., 1998), (Faraone, et al., 2003). If ADHD is under reported in females, Africa and the Middle East and in the adult population, the worldwide incidence of ADHD must be higher than 5.29%.
The percent of school aged children diagnosed with ADHD in the USA is estimated at 11% with the prevalence in males being slightly more than twice that of females. (Centers for Disease Control and Prevention, 2014b). While the number of females diagnosed may be significantly under represented this figure is likely to be a more accurate representation of the global prevalence of ADHD. The percentage of children (4-17 years of age) diagnosed with ADHD in the USA has increased from 7.8% in 2003 to 11.0% in 2011 with an average on year increase of 5%. This represents an estimated increase of 2 million children diagnosed with ADHD in the USA between 2003 and 2011 (Centers for Disease Control and Prevention, 2014b). It is unclear if this increase represents an increase in the prevalence of ADHD, an increase in the reported incidences or a combination of both.
The prevalence of ADHD in adults aged 18-44 in the USA in 2006 was estimated at 4.4% (Kessler, et al., 2006) suggesting that a significant number of cases of ADHD diagnosed in childhood may continue through adulthood. The estimation may be an underestimation due to historic reporting biases.
References to research.
To do: Convert the reference style from Harvard to conform with the rest of the wiki.
American Psychiatric Association, 2013. Diagnostic and statistical manual of mental disorders (DSM-5). Washington D.C.: American Psychiatric Association.
Arcos-Burgos, M. et al., 2010. A common variant of the latrophilin 3 gene, LPHN3, confers susceptibility to ADHD and predicts effectiveness of stimulant medication. Molecular Psychiatry, Volume 15, pp. 1053-1066.
Banaschewski, T. et al., 2006. Colour perception in ADHD. Journal of child psychology and psychiatry, and allied disciplines, 47(6), pp. 568-572.
Bussing, R. et al., 1998. Explanatory Models of ADHD Do They Differ by Ethnicity, Child Gender, or Treatment Status?. Journal of Emotional and Behavioral Disorders, 6(4), pp. 233-242.
Castellanos, F. X., Sonuga-Barke, J. S., Milham, M. P. & Tannock, R., 2006. Characterizing cognition in ADHD: beyond executive dysfunction. Trends in Cognitive Sciences, 10(3), pp. 117-123.
Centers for Disease Control and Prevention, 2014a. Attention-Deficit / Hyperactivity Disorder (ADHD) Symptoms and Diagnosis. [Online] Available at: http://www.cdc.gov/ncbddd/adhd/diagnosis.html [Accessed 10 September 2014].
Centers for Disease Control and Prevention, 2014b. Attention-Deficit / Hyperactivity Disorder (ADHD) Key Findings : Trends in the Parent-Report of Health Care Provider-Diagnosis and Medication Treatment for ADHD: United States, 2003—2011. [Online] Available at: http://www.cdc.gov/ncbddd/adhd/features/key-findings-adhd72013.html [Accessed 12 September 2014].
Centers for Disease Control and Prevention, 2014c. Attention-Deficit / Hyperactivity Disorder (ADHD): Facts About ADHD. [Online] Available at: http://www.cdc.gov/ncbddd/adhd/facts.html [Accessed 11 September 2014].
Cummins, M., 2014. %0 Tools To manage Your Adult ADHD - UPDATED. [Online] Available at: http://marlacummins.com/50-tools-to-manage-your-adult-adhd/ [Accessed 11 September 2014].
Czamara, D. et al., 2013. Children with ADHD symptoms have a higher risk for reading, spelling and math difficulties in the GINIplus and LISAplus cohort studies, s.l.: PLOS One.
de Cock, M., Maas, Y. G. & Van De Bor, M., 2012. Does perinatal exposure to endocrine disruptors induce autism spectrum and attention deficit hyperactivity disorders?. Acta Paediatrica (Review), 101(8), pp. 811-818.
Demurie, E., Roeyers, H., Baeyens, D. & Sonuga-Barke, E., 2011. Common alterations in sensitivity to type but not amount of reward in ADHD and autism spectrum disorders. Journal of Child Psychology and Psychiatry, 52(11), pp. 1164-1173.
Duffy, F., n.d. The Write Tools for ADHD Students. [Online] Available at: http://www.additudemag.com/adhd/article/9365.html [Accessed 11 September 2014].
Faraone, S. V., Sergeant, J., Gilberg, C. & Biedrman, J., 2003. The worldwide prevalence of ADHD: is it an American condition?. World Psychiatry, 2(2), pp. 104-113.
Franke, B. et al., 2012. The genetics of attention deficit/hyperactivity disorder in adults, a review. Molecular Psychiarty, 17(10), pp. 960-987.
Germanò, E., Gagliano, A. & Curatolo, P., 2010. Comorbidity of ADHD and Dyslexia. Developmental Neuropsychology, 35(5), pp. 475-493.
Kadesjö, B. & Gillberg, C., 2001. The Comorbidity of ADHD in the General Population of Swedish School-age Children. Journal of Child Psychology and Psychiatry, 42(4), pp. 487-492.
Kessler, R. C. et al., 2006. The prevalence and correlates of adult ADHD in the United States: results from the National Comorbidity Survey Replication. The American journal of psychiatry, 163(4), pp. 716-723.
Lindsay, R. L., Tomazic, T. & Accardo, P. J., 2001. Attentional function as measured by a Continuous Performance Task in children with dyscalculia. Journal of developmental and behavioral pediatrics, 22(5), pp. 287-92.
Martinussen, R., Hayden, J., Hogg-Johnson, S. & Tannock, R., 2005. A Meta-Analysis of Working Memory Impairments in Children With Attention-Deficit/Hyperactivity Disorder. Journal of the American Academy of Child & Adolescent Psychiatry, 44(4), pp. 337-384.
Mayo Clinic, n.d. Attention-deficit/hyperactivity disorder (ADHD) in children Treatments and drugs. [Online] Available at: http://www.mayoclinic.org/diseases-conditions/adhd/basics/treatment/con-20023647 [Accessed 22 September 2014].
Meyer, A. & Sagvolden, T., 2006. Fine motor skills in South African children with symptoms of ADHD: influence of subtype, gender, age, and hand dominance. Behavioral and Brain Functions, Volume 2, pp. 2-33.
National Resource Center on ADHD, n.d. About ADHD Causes and Brain Chemistry. [Online] Available at: http://www.help4adhd.org/en/about/causes [Accessed 15 September 2014].
Nigg, J. T., 2009. Cognitive Impairments Found With Attention-Deficit/Hyperactivity Disorder. [Online] Available at: http://www.psychiatrictimes.com/adhd/cognitive-impairments-found-attention-deficithyperactivity-disorder [Accessed 10 September 2014].
Pauc, R., 2005. Comorbidity of dyslexia, dyspraxia, attention deficit disorder (ADD), attention deficit hyperactive disorder (ADHD), obsessive compulsive disorder (OCD) and Tourette's syndrome in children: A prospective epidemiological study. Clinical Chiropractic, 8(4), pp. 189-198.
Polanczyk, G. et al., 2007. The worldwide prevalence of ADHD: a systematic review and metaregression analysis. The American Journal of Psychiatry, 164(6), pp. 942-948.
Semrud-Clikeman, M. et al., 1992. Comorbidity between ADDH and Learning Disability: A Review and Report in a Clinically Referred Sample. Journal of the American Academy of Child & Adolescent Psychiatry, 31(3), pp. 438-448.
Sinfield, J., 2014. Colors and ADHD: How Color Coding Can Make Your Life Easier. [Online] Available at: http://untappedbrilliance.com/colors-adhd [Accessed 22 September 2014].
Smith, M. & Segal, R., n.d. Adult ADD / ADHD Self-Help. [Online] Available at: http://www.helpguide.org/mental/adhd_add_adult_strategies.htm [Accessed 10 September 2014].
Tartakovsky, M., 2013. 15 ADHD-Friendly Tips to Fire Up Your Focus. [Online] Available at: http://psychcentral.com/lib/15-adhd-friendly-tips-to-fire-up-your-focus/00010767 [Accessed 10 September 2014].
Watson, S., 2014. The Best ADHD iPhone & Android Apps of the Year. [Online] Available at: http://www.healthline.com/health-slideshow/top-adhd-android-iphone-apps#1 [Accessed 18 September 2014].
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