Lecture 13, 14 + 15 - ADHD

Question 1

What section is ADHD in the DSM-V

Answer 1

Neurodevelopmental disorders

Was in DSM-IV: Previously in the Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence chapter

Question 2

Diagnostic criteria of ADHD

Answer 2

1. Six (or more) symptoms of inattention(must be inconsistent with developmental level) for at least six months (For people 17 or up need 5 symptoms)
2. Six (or more) symptoms of hyperactivity-impulsivity (must be inconsistent with developmental level) for at least six months (For people 17 up need 5) Important that don’t need both hyperactivity and impulsivity

Some hyperactive-impulsive or inattentive symptoms that caused impairment were present before the age of 12 (USED TO BE 7)
• Some impairment from the symptoms is present in 2 or more settings
• There must be clear evidence of clinically significant impairment in social, academic, or occupational impairment.

Question 3

What are the 3 subtypes of ADHD and they’re defining features

Answer 3

1) Inattentive - distractable, quiet, lost in space, loses things, daydreams, disorganized, forgetful
2) Combined - features from both sides
3) Hyperactive-Impulsive - fidgety, restless, always moving, talks a lot (blurts out answers, asks inappropriate questions), clumsy, difficulty waiting turn

Question 4

What aspect of “attention” is affected in ADHD?

Answer 4

sustained attention

Question 5

What are some ways to assess attention deficits?

Answer 5

CPT (Continuous performance test)

- Child looks at series/stream of letters and is told to press a button whenever they see a certain combination (ex: AZ)

Question 6

What kind of errors to kids with ADHD make on CPT?

Answer 6

Errors of commission: pressing the button when the sequence isn’t there (shows impulsivity)
Errors of omission: failure to press the button when the sequence IS there (shows inattention)

Question 7

How do we measure impulsivity?

Answer 7

Stop task.

Look at screen and X or O show up. Supposed to press X when X shows up and O when O shows up ( GO trials)
However, when a tone is played they need to inhibit their action and not press (stop trials).

• Kids with ADHD have trouble with the stop trials (impulsive errors)

Question 8

What is the prevalence of the 3 subtypes and why?

Answer 8

In clinical samples the combined subtype is most common
In community samples the inattentive subtype is most common.

We see this difference because the combined is more severe/disruptive and these people are more likely to get help.

Question 9

What are some comorbidities with ADHD?

Answer 9

Oppositional Defiant Disorder (ODD) - 35% -70%
CD (Conduct disorder) - 30%-50%
Learning Disabilities
Anxiety disorders (The inattentive type most) - 25%-35%

Inattentive also less comorbid with ODD/CD than hyperactive-impulsive

Question 10

Prevalence overall

Answer 10

3%-7% of all children
But especially high in North America

More boys than girl (9:1 - 4:1)
Except when you look at just inattentive 2:1

Question 11

What are some adult outcomes?

Answer 11

Tend to work instead of going to school

- More do neither work nor school compared to control (22% vs. 7%)

Question 12

What are some deficits of ADHD

Answer 12

executive function
social behavior
poor functioning at home and at school

Question 13

What does Barkley propose?

Answer 13

• Barkley proposes that a problem of behavioral inhibition impedes other executive functions, all of which are important for adaptive behaviors in school (holding information in short term memory) and social behavior (regulating affect)
• This deficit is associated with the functioning of the frontal lobes

Question 14

Barkley’s model of ADHD

Answer 14

Low Behavioural inhibition leads to –>
Multiple executive deficits (working memory, internalization of speech, self-regulation of affect, motivation and arousal, reconstitution) –> leads to
Problems in Motor Control System: inflexible, impulsive lacking in focus

explains that ADHD is a disorder in which one cannot regulate emotion (limbic system involved -emotion& frontal lobes).

Question 15

How heritable is ADHD?

Answer 15

ACE model shows hyperactivity ~0.8 for A and ~0.2 for E…

Question 16

What genes seem to be linked?

Answer 16

Two genes important for dopamine activity have been linked to hyperactivity (DRD4 and DAT1)

Question 17

Is there a gene x environment reaction in ADHD?

Answer 17

Children who are exposed to inconsistent parenting AND who have the risky genotype (D4 dopamine receptor gene or DRD4) have the highest number of ADHD symptoms

Question 18

What are some neurobiological differences in kids with ADHD

Answer 18

Frontal - striatal pathways (circuits linking the prefrontal cortex and midbrain structures such as the caudate nucleus)
• Smaller volume of the caudate nucleus and right prefrontal cortex
• Lower activation of circuit, as well as other structures involved in self-regulation (anterior cingulate gyrus)
• decreased volume of the cerebelllum
• Lower dopamine and norepinephrine levels
• This circuit is important in the control of motor behavior, particularly inhibition and other executive function

** Caudate nucleus has structural deficits (smaller) AND functional deficit (less active)

Question 19

Is hypoactivationof the frontal areas of the brain related to ADHD or conduct disorder (aggression)?

Answer 19

Did a B.Switch task: showed that frontal abnormalities are more closely linked to ADHD than conduct disorder

Question 20

To check if changes in brain circuit are genetic - what study was performed?

Answer 20

cognitive interference task, like the Stroop, in 42 adult with ADHD
•10R/10R is the risky genotype
•9R is the low risk allele
•Low fMRI activation observed only in the ADHD adults with the 10R/10R genotype

Question 21

What are other factors in the development of ADHD?

Answer 21

• Prenatal smoking and alcohol use, as well as other obstetric complications
• Psychosocial factors may play a small role in the etiologyof ADHD, but likely play an important role in the developmental course of the disorder
• Goodness of fit: Match between the child’s temperament and parent’s interactional style
• Early effective management of ADHD can make the difference between development of severe maladaptation (severe antisocial problems) and normal functioning.

Question 22

Many think that ADHD is most common in North America! Is this true?

Answer 22

NO.
•ADHD is found in all countries and cultures
•Highest rates are NOT in the North America
•European and North American rates are similar
•Highest rates in South America and Africa (8-12%)
•Most geographic differences disappear when methodological factors are accounted for
However, medication is used most in North America

Question 23

What is ADHD treatment aimed at?

Answer 23

• treating symptoms

- modify environment

Question 24

What is the most common treatment for ADHD and how do they work?

Answer 24

Stimulants. 
Mechanism of action
•Not known
•Stimulants cause the release of monoamines (NE, DA, 5-HT) from presynaptic neuron
- Block reuptake
•Believed to influence fronto-striatal monamine pathways
• Side effects
- Delay of sleep onset
- Headache
- Reduced appetite
- Jitteriness
- Stomach acheDysphoria
- Emotional blunting?
•Long term effects? (no evidence of long-term harm)

Question 25

What is a downside of using stimulants?

Answer 25

• Long term use

- Take them multiple times a day (however, changing with slow release patches and pills)

Question 26

Do stimulants improve cognition?

Answer 26

Yes.
Effect sizes are smaller than studies measuring clinical symptoms.
Suggests the medications are improving core deficits in ADHD

Question 27

Article 6 - Panksepp

Main ideas.

Answer 27

Play can diminish ADHD symptoms.

• Removed cortex of some rats and checked if they still played like normal - They did. THEREFORE: Play is from a deep and primitive part of the brain.
• Play develops social skills - Give and Take of interactions (limits)
• Rats that played more was more desirable.

Major premise: Is the use of psychostimulants beneficial in the long term? Possible negative consequence:
- Psychostimulants reduce rough and tumble play
• Social play is adaptive in that it promotes adaptive social learning, empathy, and self-regulation.
• Play elicits neurotrophic (growth-related BDNF, for example) and altered gene expression changes in the brain.
• That is, play is important neural development, particularly maturation of the prefrontal cortex
• Stimulants work because they seem to increase activation in frontal cortex important in regulating behavior and attention
• **Drug-and play-induced changes in the brain are different. Not sure if the drug-related changes are adaptive.

Question 28

Does stimulant use predict later substance use problems?

Answer 28

A large Swedish population study actually found that stimulant use predicted lower rates of serious substance use problems over a four year period

Question 29

How is behavioural therapy used?

Answer 29

• Behavior therapy: uses the principles of learning, operant conditioning, to alter problematic behavior
• Manipulations of privileges and tangible consequences: Token economy, the use of reinforcers (points, tokens) to reinforce positive behavior, or punish (loss of points, tokens, time out) inappropriate behavior
• Key aspects of token economy:
• Selection of clear target behaviors and rewards
• Immediate consequences, frequent feedback
• Simplicity and clear guidelines
• 100% consistency
• Parent training: education and child management skills.
• Teacher training, classroom management

Question 30

Is combined (psychological and drug) treatment better than either treatment alone?
What study was used to look into this?

Answer 30

• Study looked at long term effects of different treatment groups.
• 600 kids, 7-9 y.o. w/ADHD-C.
• 4 conditions: meds, behavioural therapy, combined, typical community treatment (control)

RESULTS

• All treatments helped
• the drug alone and the combined were both more efficacious when looked at in end of treatment than just therapy or control (community treatment)
• this suggests that medication is mostly the cause for success.
• advantage of the combined treatment: it reduced internalizing and externalizing symptoms more than the other treatments at the end of the treatment.
• at follow-up assessments all groups were equivalent.