Attention/Deficit-Hyperactivity Disorder (ADHD) ADHD

Lisa B. Thorell, PhD

MBD

Department of Clinical Neuroscience, Division of Psychology

ADHD + motorcoordination problems

Karolinska Institutet

ADHD as developmental delay

DAMP Dysfunction in Attention Motor Control and Perception

Quantitative rather than a qualitative difference between children with ADHD and controls

Developmental psychopathology approch

-Hyperactivity -Impulsivity -Inattention

Attention Deficit Hyperactivity Disorder

Normally developing children

Children with ADHD

Baby

Preschool

School

Teenage

Adult

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ADHD = frontal dysfunction


Individuals with ADHD have poor executive functions (and we know that the executive functions are based in the frontal lobes)




EEG shows frontal underactivation




MRI shows smaller frontal lobe (right side)




fMRI shows less frontal activation among children when asked to perform a task that requires attention or response inhibition.

Most researchers do not believe that psychosocial factors directly cause the disorder 




Complications prenatally, during delivery or during infancy (e.g. oxygen deprivation during birth)




Smoking/alkohol (and stress) during pregnancy Family and adoption studies have shown that there is a genetic component to ADHD






This does not mean that there is ONE ADHD gene. Rather a large number of genes (primarily dopamine related genes) have been shown to be associated with the disorder.

Theme 1

They are important for how the disorder is developing over time and the presence of comorbid disorders such as ODD and CD.

Psychosocial factors and ADHD: 

Parental stress (indirectly linked to unemployment, bad psychiatric health). Some studies have linked parental stress during pregnancy to ADHD. However, there effects usually disappear when controllig for genetic effects.



Low parental sensitivity



Parenting (”goodness-of-fit with the child’s temperament important)

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Inhibitory control




A relatively large subgroup of children with ADHD do not have executive function deficits Executive functions strongly related to emotional and motvational factors. Could this explain additional variance in ADHD symptoms? 

Verbal working memory

Non-verbal working memory

Self-regulation

Planning







Strongest relations to regulation of postive emotions (also when using children’s selfreports (Rydell, Berlin, & Bohlin, 2003; Rydell, Thorell & Bohlin, 2007)

Variable reaction times consistently associated with ADHD? State regulation? What about possible moderating and mediating factors in the child’s environment such as parent-child attachment, parenting?

Russel Barkley’s hybrid model of ADHD

Neuro-biological Basis

Psychological Process

Behavioral Expression Sonuga-Barke, 2002, 2003

Executive Circuit

Reward Circuit

Executive Dysfunction

Delay Aversion

ADHD

NO CHOICE

CHOICE

DELAY AVERSION

Minimize delay

Impulsiveness

Maximize attention to non-temporal stimulation

Inattention

Hyperactivity

Sonuga-Barke, 2002, 2003

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Computerized working memory (WM) training can improve both working memory and other cognitive functions, and lead to lower symptom levels in school-aged children with ADHD (Klingberg et al., 2004, 2005)




It has also been demonstrated that WM training leads to increased activity in frontal and parietal cortex among healthy adults (Olesen et al., Nature Neuroscience, 2004)

Theme 3

Training of working memory, which improves working memory capacity, is associated with changes in the density of cortical dopamine D1 receptors (McNab et al., Science)

Effects of WM training in school children with ADHD Klingberg et al: 2004, 2005

Arbetsminne Treatment

Intelligens 14

Placebo

5

3 2 1 0 -1

Pre-post score difference on Raven's Progressive Matrices

Pre-post score difference on Corsi Block Tapping Task

4

Treatm ent

Huvudrörelser 1000

Placebo

Treatment

Placebo

800

12

600

10 8 6 4 2 0

Pre-post score difference on Number of Head Movements

6

400 200 0 -200 -400 -600 -800

-2

-2

-3

-4

b.

-1000

c.

-1200

Staplarna visar förändring över tid (dvs när man jämför barnens prestation innan och efter träningen. Röda staplar (vänster) är experimentgruppen och gröna (höger) är placebogruppen.

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Effects of WM training in healthy adults Olesen et al 2004 a

b

parietal cortex (intra-, inferior and superior)

COGNITIVE TRAINING IN PRESCHOOL CHILDREN

parietal cortex (intra-, inferior and superior) middle frontal gyrus

c d

caudate nucleus

d

thalamus

MUMSARNA

5










Significant effects on both verbal and spatial working memory after 5 weeks of training Training of inhibitory control did not result in any significant effects  Ceiling effects for some measures  Problems with manipulating task difficulty? Future studies should investigate…  …the effect of genes  … clinical samples of children with ADHD  … other clinical groups  … training of other cognitive functions besides working memory and inhibitory control  … the effect of training in combination with other types of interventions (e.g., medication, parent education)

Executive function deficits as a riskfactor for ADHD Berlin, L. & Bohlin, G. (2002). Response inhibition, hyperactivity and conduct problems among preschool children. Journal of Clinical Child and Adolescent Psychology, 31, 242251. Berlin, L. & Bohlin, G., & Rydell, A-M. (2003). Relations between inhibition, executive functioning, and ADHD-symptoms: A longitudinal study from age 5 to 8½. Child Neuropsychology, 9, 255-266 Berlin, L. & Bohlin, G., Nyberg, L., & Janols, L-O. (2004). How well can measures of executive functioning discriminate between ADHD children and controls? Child Neuropsychology, 10, 1-13. Thorell, L. B. & Wåhlstedt, C. (2006). Executive Functioning Deficits in Relation to Symptoms of ADHD and/or ODD in Preschool Children. Infant and Child Development, 15, 503-518 Brocki, K.C., Nyberg, L., Thorell, L.B. & Bohlin, G. (2007). Early Concurrent and Longitudinal symptoms of ADHD and ODD: Relations to different types of Inhibitory Control and Working Memory. Journal of Child Psychology and Psychiatry, 48, 1033-1041 Diamantopoulou, S., Rydell, A-M., Thorell, L. B., & Bohlin (2007). Impact of Executive Functioning and Symptoms of Attention Deficit Hyperactivity Disorder on Children’s Peer Relations and School Performance. Developmental Neuropsychology, 32, 521-542.

Thorell, L.B. (2007). Do delay aversion and executive function deficits make distinct contributions to the functional impact of ADHD symptoms: A study of early academic skill deficits. Journal of Child Psychology and Psychiatry, 48, 1061-1070 Wåhlstedt, C., Thorell, L.B., & Bohlin, G. (2008). ADHD Symptoms and Executive Function Impairment:Early Predictors of Later Behavioral Problems. Developmental Neuropsychology, 33, 160-178 Thorell, L.B. & Nyberg, L. (2008) The Childhood Executive Functioning Inventory (CHEXI): A new rating instrument for parents and teachers. Developmental Neuropsychology, 33, 536-552. Lindqvist, S. & Thorell, L.B. (2009). Manipulating task difficulty in laboratory measures of inhibitory control: A brief report. Child Neuropsychology, 15, 1-7 Wåhlstedt, C., Thorell, L.B., & Bohlin, G. (2009). Heterogeneity in ADHD: Neuropsychological Pathways, Comorbidity and Symptom Domains. Journal of Abnormal Child Psychology, 37, 551-564. Brocki, K.C., Eninger, L., Thorell, L.B., & Bohlin, G. (2010). Interrelations Between Executive Function and Symptoms of Hyperactivity/Impulsivity and Inattention in Preschoolers: A Two Year Longitudinal Study. Journal of Abnormal Child Psychology, 38, 163-171 Thorell, L.B., Eninger, L., Brocki, K.C., & Bohlin, G. (2010). Childhood Executive Function Inventory (CHEXI): A Promising Measure for Identifying Young Children with ADHD? Journal of Clinical and Experimental Neuropsychology, 32, 38-43.

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Executive functions, ADHD and treatment Thorell, L.B., Lindqvist, S., Bergman Nutley, S., Bohlin, G., & Klingberg, T. (2009). Training and transfer effects in executive functioning in preschool children. Developmental Science, 12, 106-113 Thorell., L.B. & Dahlström, K. (2009). Children’s self-reports of perceived effects of taking stimulant medication for ADHD. Journal of Attention Disorders, 12, 460-468.

ADHD symptoms and EF in relation to social functioning Rydell, A-M., Berlin, L., & Bohlin, G. (2003). Emotionality, emotion regulation, and adaption among five-to-eight-year old children. Emotion, 3, 30-47. Rydell, A-M., Thorell, L. B., & Bohlin, G. (2007). Emotion regulation in relation to social functioning: An investigation of child self-reports. European Journal of Developmental Psychology, 4, 293-313 . Diamantopoulou, S., Rydell, A-M., Thorell, L. B., & Bohlin (2007). Impact of Executive Functioning and Symptoms of Attention Deficit Hyperactivity Disorder on Children’s Peer Relations and School Performance. Developmental Neuropsychology, 32, 521542. Thorell, L.B. (2007). Do delay aversion and executive function deficits make distinct contributions to the functional impact of ADHD symptoms: A study of early academic skill deficits. Journal of Child Psychology and Psychiatry, 48, 1061-1070

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