Attention Deficit Hyperactivity Disorder
(ADHD)
PSY4105
Dr. Caroline Sullivan
Today
ADHD
◦ Diagnostic criteria
◦ Course & etiology
◦ Comorbid conditions
◦ Neuropsychological deficits
◦ Functional deficits
Academic
Family
Social
Next time:
◦ Evaluation and treatment
Fact or Fiction?
ADHD usually persists into adulthood
◦ FACT
People with ADHD have average IQ
◦ FACT
ADHD only affects boys
◦ FICTION
Children with ADHD who take medication are more
likely to abuse drugs when they become teenagers
◦ FICTION
Fact or Fiction? (cont’d)
The rate of diagnoses of ADHD in children is increasing
◦ FACT
Children are more likely to show signs of ADHD if they
consume a lot of food dyes
◦ FICTION
Kids with ADHD are more likely to repeat grades
◦ FACT
A diagnosis of ADHD is more likely than physical
conditions to lead to long-term economic disadvantage
◦ FACT
What is Attention-Deficit /
Hyperactivity Disorder (ADHD)?
ADHD is a
neurobiological problem
that is usually first
noticed in the preschool
and early school years.
Inattention Hyperactivity Impulsivity
Symptoms of Inattention
At least 6 of 9 symptoms:
Poor attention to details,
makes careless mistakes
Difficulty concentrating
Doesn’t seem to listen
Fails to follow through on
instructions & finish work
Difficulty organizing work and
self
Avoids/dislikes lengthy,
effortful tasks
Loses things Meet my son, Marleau
Easily distracted
Forgetful
Types of Attention
1) Attention capacity:
Can’t remember phone number unless you write it down
2) Selective Attention:
Distraction – can’t do homework if tv on in another room
3) Sustained Attention:
Ability to pay attention when tired or disinterested in the
subject
Which is the primary deficit in ADHD?
◦ Sustained attention – especially for repetitive,
structured, and uninteresting tasks
Symptoms of Hyperactivity & Impulsivity
At least 6 of 9 symptoms:
Fidgets or squirms
Leaves seat when not
appropriate
Runs or climbs excessively
Difficulty playing quietly
“On the go” or “driven by
a motor”
Blurts out answers to
questions
Talks excessively
Difficulty awaiting turn
Interrupts or intrudes on
others
Which behaviours match
which symptoms?
Inattention Hyperactivity
Poor attention to details, Fidgets or squirms
makes careless mistakes Leaves seat when not
Difficulty concentrating appropriate
Doesn’t seem to listen Runs or climbs excessively
Fails to follow through on Difficulty playing quietly
instructions & finish work “On the go” or “driven by a
Difficulty organizing work and motor”
self
Avoids/dislikes lengthy,
Impulsivity
effortful tasks Talks excessively
Loses things Difficulty awaiting turn
Easily distracted Interrupts or intrudes on
others
Forgetful
Blurts out answers to
◦* Associated with poor academic
questions
performance *
Symptoms must be.....
Persistent Pervasive Impairing
( > 6 months) ( > 1 setting)
2 Dimensions - 3 Specifiers
Inattentive Hyperactive /
Subtype Impulsive
“ADD” Subtype
Combined Type
“Classic ADHD”
DSM-5
Major Changes:
• ADHD is categorized under neurodevelopmental disorders
• Subtypes changed to “specifiers of current presentation”
• Is more relevant for diagnosis of adult ADHD
Moderate Changes:
“Age of onset” criteria changed – symptoms before age 12
Minor Changes:
Requirement of multiple informants included
Autism and PDD have been removed from exclusionary
criteria
More examples of symptoms
Prevalence
7-12% of school age population worldwide
2nd most prevalent children’s mental health
disorder
Most prevalent referral in mental health clinics
Male bias
In Ontario
2.1 millions students
~ 100,000 with ADHD
1-3 students per class
ADHD & Gender
2-4% of girls
6-9% of boys
But referral, assessment and diagnosis of boys with
ADHD is much more common (2.5:1)
Clinical sample: 6:1
Inattention type is relatively more
common in girls
Slightly more common with lower SES
ADHD is a neurodevelopmental disorder
“An illness of the central nervous
system caused by known genetic,
metabolic, or other biological
factors”
Parts of the brain involved in ADHD
Superior Frontal Anterior
Parietal Eye Field Cingulate
Posterior Lobe Gyrus
Area Frontal
Area
Temproparietal
Junction
Prefrontal
Cortex
Thalamus
Pulvinar
Superior
Colliculus
Posner & Rothbart (2007), Annual Rev
Psych
ADHD persists into adolescence &
adulthood, but changes in its
behavioural manifestation
Childhood Adolescence Adulthood
1o Combined 1o Inattentive 1o Inattentive
Type Type Type
OVERT COVERT
Course
Infancy – difficult temperament
◦ Irritable
◦ Over-active
◦ Unpredictable behaviour
◦ Erratic eating and sleeping
Preschool – symptoms become noticeable
◦ Impulsive behaviour
◦ Easily bored
◦ Over-reactive emotionally
◦ Non-compliance and defiance
Course
Early school years– diagnosis often made
◦ School requires attention and compliance
◦ Defiance and conduct problems increase
◦ Academic/learning problems
◦ Hyperactivity slowly declines
Adolescence
◦ Many individuals “outgrow” ADHD symptoms
in adolescence
◦ Symptoms continue for about 50% of children
◦ By adulthood, individuals with ADHD perform
normally on most measures of attention
Functional Deficits
Etiology
Genetic influences
◦ Strongly genetic
◦ 80% heritability
Reduced dopaminergic activity
Reduced blood flow in the frontostriatal
networks
Etiology
Many poorly supported or discredited
theories exist to explain ADHD
◦ Food allergies
◦ Poor parenting techniques
If anything, bidirectional causality
◦ Vaccines ( )
Sugar consumption and exposure to
screen time can increase ADHD
symptoms but do not cause it
80% Comorbidity
Learning disorders = 25%
◦ Especially writing disorder
Oppositional Defiant Disorder (ODD) = 50% by age 7
Anxiety disorders = 25%
Mood disorders = 20-30%
Tics = 20%
Sleep disorders = 20%
Risk-taking behaviours and substance use
Neuropsychological Findings
What is working memory?
A limited-capacity cognitive
system that allows us to actively hold and use critical
information in mind despite ongoing distraction
Auditory-Verbal Visual-spatial
E.g. Digit span E.g. CogMed
Working Memory is
Impaired in ADHD
Many people with ADHD exhibit significant
impairments in working memory:
• Particularly those with symptoms of inattention
• Particularly for visual-spatial information
• Impairments evident across all ages, but diminish in
adolescence
• Problems evident on standardized tests
• Working memory is the one cognitive impairment
that is really important in education!
Let’s think about how working
memory deficits might affect:
Learning the alphabet
Following a conversation
Writing a paragraphe
Playing a game (e.g. cards)
Learning to add and substract
Genetic basis
Persists into adulthood
Neurocognitive disorder – not just a
behavioural disorder
Neuropsychological deficits (particularly
working memory) central to ADHD
Inattention, not hyperactivity/impulsivity, is
key in learning problems
