The Triad: Obsessive Compulsive, Tourette’s Disorder, and ADHD.

It is 10.30pm. I lie in bed. My eyes close but I cannot sleep. I hear my twelve-year-old son from his room. He lies in bed and snorts. The air leaves his nostrils in loud dramatic puffs. I count the repetitive sounds. He snorts about every three seconds. This behaviour continues until he finally sleeps. I doze off. Snorting is just one of his tics.
My son has Tourette’s syndrome. He displays unusual repetitive behaviours. These include both vocal tics and motor, or physical, tics. Tourette’s patients exhibit at least one vocal and one motor tic at any given time for at least one year. Tics wax and wane in their intensity. Tics appear and disappear without warning. One tic may replace another, but a child is rarely tic-free.

The Bigger Picture
My son also displays Attention Deficit Hyperactivity Disorder (ADHD). He blurts out information and fidgets incessantly. He also manifests obsessive-compulsive behaviours. He scrubs his teeth several times before sleep.
According to a 2015 case study published by The Journal of Child and Adolescent Psychopharmacology, my son is not alone in his triple diagnosis. Dr. Rice, the study’s lead researcher, refers to the co-occurrence of Tourette’s syndrome, Obsessive Compulsive Disorder (OCD), and ADHD as the “triad.”
Dr. Rice states that while the disorders often co-occur, symptoms have a unique developmental course in each child. My son displayed the “triad” just shy of his seventh birthday.

The Basal Ganglia
Dr. Rice states that the brain region called the Basal Ganglia connects the three disorders. The Basal Ganglia sits at the bottom of the forebrain. Researchers believe the basal ganglia co-ordinates voluntary motor movements. Voluntary movements include the learned repetitive behaviours witnessed in Tourette’s patients and OCD. The Basal Ganglia connects to the Pre-Frontal Cortex, the centre of higher reasoning. Dr. Rice explains that the two regions work together to improve memory and decision-making functions. Impulsive behaviours may result from deficits in connectivity between the regions.
 Is it Genetic?
Research suggests all three disorders share genetic links, yet to date, no research has identified the culprit. Dr. Rice describes the inherited deficit as “a punitive phenotype,” or an inherited lack of inhibitory control.
The developmental course of the disorder means the most disruptive behaviours associated with ADHD often appear in early childhood. Tics usually manifest in the early school years, while obsessions and compulsions often peak in adolescence.

Medication and Tics
Many children with ADHD take medication to aid concentration and curb hyperactivity. Previous research failed to prove whether these medications aggravate tic behaviours. But current research by the American Academy of Child and Adolescent Psychiatry reports that medications used to treat symptoms of ADHD do not exacerbate tics in children.
The findings of the study are particularly pertinent because most prior research suggests that psycho-stimulant medications trigger tics. As a result, the Food and Drug Administration Agency of the United States (FDA) issues warnings on all psycho-stimulant medications listing tics as an adverse effect. The warnings deter doctors from prescribing psycho-stimulants to any child with a family history of tics. Psycho-stimulants remain the best-known solution for ADHD symptoms.

What are Psycho-stimulant Medications?
Psycho-stimulants, or amphetamines, activate the central nervous system to increase dopamine in the brain. Dopamine is an important neurotransmitter. Neurotransmitters help connectivity between brain regions. For ADHD patients, increasing connectivity between brain regions improves concentration and reduces the behavioural issues associated with impulsivity.

The Study
Researchers performed a meta-analysis to examine whether medications increased tics. A meta-analysis looks at previous studies and compares results. Researchers compared twenty-two previous studies from a total of 2385 children with ADHD. The twenty-two studies together included data sets collected between 1974 and 2011.
All studies reported some increased tic behaviour after either trials with a psycho-stimulant medication, or a non-active placebo medication. All trials lasted at least seven days. The Yale Global Tic Severity Scale considers a seven-day trial the minimum sufficient for successful clinical testing.

Results of the Study
Tic behaviours increased the most after placebo treatments. Psycho-stimulant medications designed for ADHD did not increase tics. Researchers examined all FDA approved ADHD medications.

What Causes the Tics?
This new study shows ADHD medications do not exacerbate tics. Aligning with Dr. Rice’s claims, the new study suggests that tics probably result from an underlying predisposition to a tic disorder. Twenty percent of children diagnosed with ADHD posses an underlying tic disorder. Psycho-stimulant treatments generally commence before tics appear. Increases in subsequent tic behaviour may be coincidental.

Should We Medicate?
Although the new study indicates that ADHD medications do not intensify tics in children, other known side effects exist. Common side effects include appetite loss and insomnia. It is important to remember, however, that poor social skills and low academic performance often affect young ADHD patients more than any known side effect.
For my son, treating his ADHD with medication improves his social and educative success.
As for his tics, we hope they will wane naturally with age.

 

References

Berman, S. M., Kuczenski, R., McCracken, J. T., & London, E. D. (2009). Potential adverse effects of amphetamine treatment on brain and behavior: A review. Molecular Psychiatry, 14(2), 123–142. http://doi.org/10.1038/mp.2008.90

Cohen, S. C., Mulqueen, J. M., Ferracioli-Oda, E., Stuckelman, Z. D., Coughlin, C. G., Leckman, J. F., & Bloch, M. H. (2015). Meta-analysis: Risk of tics associated with psychostimulant use in randomized, placebo-controlled trials. Journal of the American Academy of Child & Adolescent Psychiatry, 54(9), 728-736. doi:10.1016/j.jaac.2015.06.011

Himle, M. B., Chang, S., Woods, D. W., Bunaciu, L., Pearlman, A., Buzzella, B., & Piacentini, J. C. (2007). Evaluating the contributions of ADHD, OCD, and tic symptoms in predicting functional competence in children with tic disorders. Journal of Developmental and Physical Disabilities, 19(5), 503-512. doi:10.1007/s10882-007-9066-4

Hirschtritt, M.E., Lee, P.C., Pauls, D.L., Dion, Y., Grados, M.A., Illmann, C., King, R.A., Sandor, P., McMahon, W.M., Lyon, G.J., Cath, D.C., Kurlan, R., Robertson, M.M., Osiecki, L., Scharf, J.M. &, Mathews, C.A. (2015). Lifetime prevalence, age of risk, and genetic relationships of comorbid psychiatric disorders in Tourette syndrome. JAMA Psychiatry.72(4), 325–333. doi:10.1001/jamapsychiatry.2014.2650

Khajehpiri, Z., Mahmoudi-Gharaei, J., Faghihi, T., Karimzadeh, I., Khalili, H., & Mohammadi, M. (2014). Adverse reactions of methylphenidate in children with attention deficit-hyperactivity disorder: Report from a referral center. Journal of Research in Pharmacy Practice, 3(4), 130–136. http://doi.org/10.4103/2279-042X.145389

Lebowitz, E., Motlagh, M., Katsovich, L., King, R., Lombroso, P., Grantz, H., Lin, H., Belntley, J., Gilbert, D., Singer, H., Coffey, B., Kurlan, R., & Leckman, J. (2012). Tourette syndrome in youth with and without obsessive-compulsive disorder and attention deficit hyperactivity disorder. European Child & Adolescent Psychiatry, 21(8), 451-457. doi:10.1007/s00787-012-0278-5

Rice, T., & Coffey, B. (2015). Pharmacotherapeutic challenges in treatment of a child with “the triad” of obsessive compulsive disorder, attention- deficit/hyperactivity disorder and tourette’s disorder. Journal of Child and Adolescent Psychopharmacology, 25(2), 176-179. doi: 10.1089/cap.2015.2522

 

Published in Communicating Science. A text for the University of Toronto, 2019

Heavy Smoking May Increase Likelihood of Tourette’s Syndrome in Newborns

Chronic smoking blackens your lungs, blocks your arteries, and causes bad breath. But how does excessive pregnant puffing affect the unborn child? Could the drag of a smoke while pregnant cause Tourette’s syndrome?

Between 1996 and 2002, the Danish National Birth Cohort (DNBC) interviewed, observed, and collected data about the lifestyle, health, and habits of nearly 100,000 pregnant Danish women. By October 2013, after re-interviewing, observing, and collecting new data from the Danish mother’s, the DNBC composed a complete data set of 73,076 women and their now teenage children.

In 2017, Dr. Browne and her team from the Icahn School of Medicine in New York studied the comprehensive Danish data to determine whether chronic smoking during pregnancy might cause Tourette’s syndrome, a neurological disorder responsible for chronic tic behaviours.

Before we delve into Dr. Browne’s findings, let’s first examine the symptoms of Tourette’s syndrome and how it affects the brain.

Tourette’s Syndrome and Tics

Doctors believe that Tourette’s syndrome arises from alterations in the development of brain circuits during pregnancy. Specifically, subtle changes may occur in the Thalamus, Basal Ganglia, and the Pre-Frontal Cortex. Tics, or sudden repetitive movements observed in patients with Tourette’s syndrome likely result from deficits in connectivity between these regions. Patients with Tourette’s syndrome display both physical and vocal tics over the course of at least one year.

Dr. Herrero and his associates from University of Murcia, Spain, explain that the Thalamus and Basal Ganglia sit at the bottom of the forebrain and help coordinate voluntary motor movements and behaviours. The two areas connect to the Pre-Frontal Cortex, the centre of higher reasoning. Dr. Herrero claims that together, the three regions aid working memory, decision-making functions, and voluntary movement.

brain

According to Dr. Herrero, the Thalamus, Basal Ganglia, and the Pre-Frontal Cortex work together to coordinate voluntary movements

Source: http://proprofs-cdn.s3.amazonaws.com/images/FC/user_images/1406217/9806788916.png

Tic behaviours also likely occur because of altered dopamine levels.

Dr. Herrero explains that dopamine, a neurotransmitter or a chemical messenger in the brain, allows information to pass from one neuron to another. Altered dopamine levels likely reduce connectivity between brain regions. Altered dopamine may explain the reduced voluntary control, or tics behaviours, observed in Tourette’s patients.

dopamine

Dopamine, a neurotransmitter, sends a chemical message from one neuron to another.

Source: https://www.themindfulcoach.com

The Study

The DNBC interviewed pregnant women at their 17th and 32nd week of pregnancy, and again six months after the birth of their child. During interviews, each mother disclosed whether or not she smoked. Researchers categorised the mothers’ daily cigarette consumption as either light or heavy. Light smokers puffed fewer than ten daily cigarettes, while heavy smokers dragged on more than ten.

The DNBC also collected data on the child’s sex, birth weight, mother’s age, mother’s pregnant body mass index (BMI), parental income, and parental alcohol, hashish and caffeine consumption. 73,076 of the participants possessed a complete set of data. Dr. Browne and her team  or possibly influential variables from the complete data set to ensure no other factor influenced a diagnosis of Tourette’s syndrome.

Findings

The team linked the information from the DNBC with information from the Danish National Psychiatric Central Register (DNPCR). They discovered 906 reported cases of chronic tic behaviours or diagnosed Tourette’s syndrome among the teenage cohort.

Dr. Browne and her team confirmed prenatal smoking increases the risk of the child developing Tourette’s syndrome, stating, “Heavy smoking was associated with a 66% increased risk.”

Data from the DNPCR also showed increased links between chronic prenatal smoking and Attention Deficit Hyperactivity Disorder (ADHD). Children with ADHD display attention difficulties and hyperactive behaviour. Dr. Browne and her team claim heavy prenatal smoking doubled the risk of acquiring both ADHD and Tourette’s syndrome in the sample of teens.

Eight percent of mothers in the study confessed to heavy daily smoking during their pregnancy.

Smoking and the brain

Research suggests that prenatal exposure to nicotine affects foetal brain maturation. Affected children’s brain circuitry may wire unconventionally as a result. Their altered dopamine levels may cause neurons to fire with no target in sight.

Brain structures may also look different. Depleted behavioural and voluntary motor control observed in Tourette’s syndrome and ADHD might result from these brain re-structures.

References

Browne, H. A., Modabbernia, A., Buxbaum, J. D., Hansen, S. N., Schendel, D. E., Parner, E. T., Grice, D. E. (2016). Prenatal maternal smoking and increased risk for Tourette syndrome and chronic tic disorders. Journal of the American Academy of Child & Adolescent Psychiatry, doi:10.1016/j.jaac.2016.06.010 Herrero, M., Barcia, C., & Navarro, J. (2002).

Functional anatomy of thalamus and basal ganglia. Child’s Nervous System, 18(8), 386-404. doi:10.1007/s00381-002-0604-1 4 1

 

Published in Communicating Science. A text for the University of Toronto, 2019

 

Sitting Still for Star Wars: Children with ADHD only Squirm when they Learn

Learning generates squirming in children with Attention Deficit Hyperactivity Disorder (ADHD), finds a 2017 study by researchers at the University of Central Florida. Children with ADHD experience deficits in attention, combined with excess physical activity. The new findings show that children with ADHD wriggle and squirm twice as much as typically developing children when attempting to learn. Activity surplus likely results from inefficient attention processes.

How Attention Works

According to the reputed hypothesis by Professor Alan Baddeley, working memory systems in the brain temporarily hold and manipulate information from short and long-term memory via the Central Executive System. The Central Executive sifts information and sorts it by importance. Baddeley claims that important information either remains in active use, or moves to long-term storage. According to his hypothesis, swift processing of information leads to increased attention and increased attention improves learning.

Screen Shot 2018-04-12 at 15.52.04.png

According to Baddeley, the Central Executive sifts information between short and long-term memory systems.

Source: http://www.psychologywizard.net/working-memory-ao1-ao2-ao3.html

Learning for Children with ADHD

Tasks requiring high concentration may prove difficult for children with ADHD because of deficits in working memory.

The study examined thirty-two boys with ADHD and thirty typically developing boys (all aged 8-12 years) through memorisation tasks. According to the University of Central Florida researchers, short-term memorisation tasks assess working memory strength. The tasks tested the boys’ ability to remember numbers and sequences for a short period. Typically developing boys outperformed boys with ADHD on all working memory tasks. These results appear to confirm diminished working memory processes in children with ADHD.

Squirming and Learning

Diminished working memory probably decreases concentration and promotes attention shifts. Children with decreased concentration may move their focus to more attention-grabbing stimulus. Squirming and fidgeting likely arise from frequent attention shifts.

All boys in the study watched a ten-minute educational video. Boys with ADHD moved twice as much as the typically developing boys during the learning task. According to results, poor working memory accounted for at least fifty-six percent of the inattentive behaviour.

Sitting Still for Star Wars

The two groups of boys also watched a ten-minute exert from a Star Wars film. The excerpt featured a fast paced pod race. Researchers claim that rapid paced scenes, such as the Star Wars excerpt do not tax working memory. Attention rates did not differ between the two groups. All boys sat riveted.

Results suggest children with ADHD can sit still when they choose, or rather, when the task does not tax working memory. Video games and drawing elicit similar results.

References

Baddeley, A. (2010). Working memory. Current Biology, 20(4), R136-R140. doi:10.1016/j.cub.2009.12.014

Orban, S.A., Rapport, M.D., Friedman, L.M..Eckrich, S.J., & Kofler, M.J. (2017) Inattentive behaviour in boys with ADHD during classroom: the mediating role of working memory processes. Journal of Abnormal Child Psychology. 1-15. https://doi-org.myaccess.library.utoronto.ca/10.1007/s10802-017-0338-x

 

Students with ADHD more likely to develop Internet Gaming Addiction.

It is 4:00 A.M. You sit in the basement of your house. Your thighs stick to a worn leather chair. Your armpits sweat, your eyeballs glue to the screen in front of you. The fingers of your left hand shackle a joystick. The fingers of your right hand punch the control keys. Today’s looming economics exam sinks to the depths of your subconscious.

You must kill. You lift your gaze and peer through the rubble. A tank lies just metres away. You push through the rubble and forge towards the tank.

A sniper strikes you from behind. Game over. You hit the respawn button.

You’re addicted to video games.

#

In 2017, Benjamin Pearcy and colleagues from the School of Psychology and Speech Pathology in Perth, Australia, collected self-report data from obsessive online gamers and found possible links between Internet Gaming Addiction and other mental disorders.

But is Internet Gaming Disorder real?

Internet Gaming Disorder emerged as a mental disorder in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM). Psychologists and psychiatrists around the world rely on the DSM as their main diagnostic tool. The DSM claims that the mutation from an activity to a disorder occurs when a person’s behaviour harms their everyday functioning.

Internet Gaming Disorder harms lives: it thwarts a person’s social, occupational, and psychological functioning. Gamers obsess over playing and suffer withdrawal when they stop.

Pearcy and his colleagues surveyed 404 gamers of an online gaming community. The sample included 285 adults and 119 students. Men comprised 70% of participants.

Pearcy’s team measured the gaming frequency of each participant. The team also calculated psychological stress, attention deficit and hyperactivity, anxiety, depression, and obsessive-compulsive behaviours of each participant. All measures resulted from self-report.

Results showed a high comorbidity, or co-occurrence, of other mental disorders to Internet Gaming Disorder.

Of the 404 participants in the study, twenty-two adults and twelve students self-reported as addicted online gamers. The highest comorbidity with other mental disorders occurred among the addicted gamer sample.

Addicted gamers, in particular the student sample, most frequently admitted to symptoms of Attention Deficit Hyperactivity Disorder (ADHD), a childhood disorder, marked by impulsive behaviour and an inability to concentrate. ADHD is more common in males and symptoms may continue into adulthood.

But what is the reason for this comorbidity?

A team of researchers from the Kaohsiung Medical University in Taiwan investigated possible links between Internet Gaming Disorder, ADHD, and impulsivity. Similar to Pearcy and colleagues, the researchers found a high correlation between Internet Gaming Disorder and ADHD. The Kaohsiung analysts tested participants for impulsivity through a self-report questionnaire and recorded higher scores in impulsivity among their addicted gamer sample, discovering that impulsivity increases the risk of Internet Gaming disorder. Impulsivity also increases vulnerability to addictions, including gaming addictions, and may also augment aggressive behaviour. Addicted gamers proved most likely to exhibit ADHD, aggression, and higher impulsivity scores.

Olga, an anonymous online forum for addicted gamers, provides some insight into Online Gaming Addiction and comorbid ADHD. SheeshMode, a self-disclosed gaming addict from Olga, admits, “I’m a game addict and have significant ADHD issues. It’s just really difficult for me to focus on things that don’t immediately grab my attention. Gaming did [engage me] for a long time, but it turned into a problem when I couldn’t control how long I stayed on, or how long I needed to play to feel satisfied.”

The Kaohsiung researchers conclude that Internet gaming may provide a higher sense of achievement and offer increased social support for individuals with ADHD, because gaming may offer compensation for problems in daily life associated with increased aggression and impulsivity caused by the decreased ability to concentrate on every day tasks.

Bill F, a self-disclosed gaming addict, comments on Olga: “Gaming provided constant stimulus for me, and in a way provided me with the same surge in energy that I needed to focus. However, nothing could match the trigger-happy (literally) environment of the fire-person-shooter games I played, so I wanted to do nothing else. Everything else was boring and tiring except for games.”

A supportive network and therapy aimed at changing behaviors to curb impulsivity currently offers the best route for recovery from Internet Gaming Disorder.

 

References

Pearcy, B.T.D., McEvoy, P.M., & Roberts, L.D. (2017). Internet gaming disorder explains unique variance in psychosocial distress and disability after controlling for comorbid depression, OCD, ADHD, and anxiety. Cyberpsychology. 20(2), 126-132. https://doi-org.myaccess.library.utoronto.ca/10.1089/cyber.2016.0304

Shirley, M. C., & Sirocco, K. Y. (2014). Introduction to special section: ADHD, impulsivity, and alcohol abuse. Experimental and Clinical Psychopharmacology, 22(2), 97-99. doi:http://dx.doi.org.myaccess.library.utoronto.ca/10.1037/a0036124

Lemmens, J. S., Valkenburg, P. M., & Gentile, D. A. (2015). The Internet gaming disorder scale. Psychological Assessment, 27(2), 567-582. doi:http://dx.doi.org.myaccess.library.utoronto.ca/10.1037/pas0000062

Bill, F. & SheeshMode. (2018). Online Gamers Anonymous. www.olga.org/forum.

Yen, J.Y., Lui, T.L., Wang, P.W., Chen, C.S., Yen, C.f., Ko, C.h. (2017) Association between internet gaming disorder and adult attention deficit disorder and their correlates: impulsivity and hostility. Addictive Behaviours, 64. 308-313. https://doi.org/10.1016/j.addbeh.2016.04.024

Published in Compass Professional Writing and Research Journal, 2018

ADHD Medication and Tics

Current research by the American Academy of Child and Adolescent Psychiatry reports that medications used to treat symptoms of Attention Deficit Hyperactivity Disorder (ADHD) do not exacerbate tics in children. ADHD is a common childhood disorder marked by impulsive behaviour and an inability to concentrate. The findings of the study are particularly pertinent because most prior research suggests that psycho-stimulant medications trigger tics. As a result, the Food and Drug Administration Agency of the United States (FDA) issues warnings on all psycho-stimulant medications listing tics as an adverse effect. The warnings deter doctors from prescribing psycho-stimulants to any child with a family history of tics. Psycho-stimulants remain the best-known solution for ADHD symptoms. What are Psycho-stimulant Medications? Psycho-stimulants, or amphetamines, activate the central nervous system to increase dopamine in the brain. Dopamine is an important neurotransmitter. Neurotransmitters help connectivity between brain regions. For ADHD patients, increasing connectivity between brain regions improves concentration and reduces the behavioural issues associated with impulsivity.

red

Psycho-stimulant medications appear to increase brain activity in children with ADHD.

Source: https://neuroanthropology.files.wordpress.com/2009/06/adderall-brain1.jpg?w=562

 

What are Tics?

Tics present as repetitive vocal sounds or physical actions. Tics are sudden, rapid and non-rhythmical. Tics are difficult to control. Common tics include grunting, blinking, sniffing, and throat clearing.

 

 

Untitled

Common motor tics include grimaces and blinking actions.

Source: http://kimgaitskillmd.com/psychiatrist/adult-child-psychiatrist-conditions/tic-disorders-tourettes

 

The Study

Researchers performed a meta-analysis to examine whether medications increased tics. A meta-analysis looks at previous studies and compares results. Researchers compared twenty-two previous studies from a total of 2385 children with ADHD. The twenty-two studies together included data sets collected between 1974 and 2011.       All studies reported some increased tic behaviour after either trials with a psycho-stimulant medication, or a non-active placebo medication. All trials lasted at least seven days. The Yale Global Tic Severity Scale considers a seven-day trial the minimum sufficient for successful clinical testing.
Results of the Study Tic behaviours increased the most after placebo treatments. Psycho-stimulant medications designed for ADHD did not increase tics. Researchers examined all FDA approved ADHD medications.

 

b

Ritalin (left) and Concerta (right) are two commonly prescribed psycho-stimulant medications for the treatment of ADHD symptoms.

Source: https://www.pinterest.ca/pin/246149935854994927/

 

What Causes the Tics?

This new study shows ADHD medications do not exacerbate tics. Tics probably result from an underlying predisposition to a tic disorder. Twenty percent of children diagnosed with ADHD posses an underlying tic disorder. Symptoms of ADHD also usually present before tics. Psycho-stimulant treatments generally commence before tics appear. Increases in subsequent tic behaviour may be coincidental.
Should We Medicate?Although the new study indicates ADHD medications do not intensify tics in children, other known side effects exist. Common side effects include appetite loss and insomnia. It is important to remember, however, that poor social skills and low academic performance often affect young ADHD patients more than any known side effect.

 

 

References

Berman, S. M., Kuczenski, R., McCracken, J. T., & London, E. D. (2009). Potential adverse effects of amphetamine treatment on brain and behavior: A review. Molecular Psychiatry, 14(2), 123–142. http://doi.org/10.1038/mp.2008.90

Cohen, S. C., Mulqueen, J. M., Ferracioli-Oda, E., Stuckelman, Z. D., Coughlin, C. G., Leckman, J. F., & Bloch, M. H. (2015). Meta-analysis: Risk of tics associated with psychostimulant use in randomized, placebo-controlled trials. Journal of the American Academy of Child & Adolescent Psychiatry, 54(9), 728-736. doi:10.1016/j.jaac.2015.06.011

Khajehpiri, Z., Mahmoudi-Gharaei, J., Faghihi, T., Karimzadeh, I., Khalili, H., & Mohammadi, M. (2014). Adverse reactions of methylphenidate in children with attention deficit-hyperactivity disorder: Report from a referral center. Journal of Research in Pharmacy Practice, 3(4), 130–136. http://doi.org/10.4103/2279-042X.145389

 

 

Working Memory and Reading

Reading difficulties observed in children with Attention Deficit Hyperactivity Disorder (ADHD) may result from deficits in working memory, states a new study by researchers at the University of Central Florida. ADHD is a common childhood disorder marked by impulsive behaviour and an inability to concentrate.
The 2017 study examined schoolboys with ADHD and linked poor reading skills to slow orthographic conversion. Orthographic conversion occurs when we change text into a sound-based code in the brain. Our working memory temporarily stores the code while we process and digest the information. According to the study, slow orthographic conversion leads to poor reading skills.

Badley’s Working Memory Model
Researchers based their investigation on the work of British psychologist, Alan Baddeley. Baddeley created the original working memory model in the 1970s. The working memory model proposes that temporary storage units manage different sensory information in the brain. Sensory information, such as sounds and visual information enters the working memory model administered by the central executive system. The central executive decides how and what to process. The central executive then forwards the important information to long-term memory. The central executive also retrieves relevant information from long-term memory when needed.

Uiintitled

According to Badley, sensory information enters working memory and is managed by the central executive function.

Source: https://www.simplypsychology.org/working%20memory.html

 

The Phonological Loop
According to Baddeley, reading comprehension occurs because the phonological loop, a temporary storage unit, coordinates with the central executive. Together, the two systems convert phonological information into something meaningful. Phonological information consists of sounds and words, including what we read.
The phonological loop temporarily houses phonological information. The central executive then connects the information with previously stored information in long-term memory. The process sifts information and keeps related data in the working memory. Reading and conversations make sense because of the interrelated processes.

 

Untitled

According to Badley, auditory information is temporarily stored in the phonological loop before further processing.

Source: https://www.simplypsychology.org/working%20memory.html
Findings of the Study
The study examined thirty-one ADHD diagnosed and thirty normally developing boys aged eight to twelve years of age. All boys completed orthographic conversion tasks over four consecutive test sessions. Orthographic conversion tasks assess reading comprehension and recall abilities. Results indicated poor orthographic conversion in boys diagnosed with ADHD.
Researchers concluded that the poor test results of the ADHD group indicate deficiencies in both executive function and the phonological loop. Deficiencies may arise from a bottleneck entering the phonological loop. The bottleneck subsequently increases demands on the central executive. Reading comprehension and recall abilities may suffer as a result.
References
Baddeley, A. (1996). The fractionation of working memory. Proceedings of the National Academy of Sciences of the United States of America, 93(24), 13468–13472. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC33632/pdf/pq013468.pdf

Friedman, L.M., Rapport, M.D., Raiker, J.S., Orban, S.A., & Eckrich, S.J. (2017). Reading comprehension in boys with ADHD: the mediating roles of working memory and orthographic conversion. Journal of Abnormal Child Psychology. 45(2). 273-287. https://doi-org.myaccess.library.utoronto.ca/10.1007/s10802-016-0171-7