ADHD: What is it?

Presented at a Public Forum in
Singapore on 2 June 2007
ADHD: What is it?
Rosemary Tannock, PhD
Professor & Canada Research Chair in
Special Education,University of Toronto;
Senior Scientist, Sickkids Hospital, CANADA
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ADHD: Some Questions and Answers
What is ADHD?
Why does my child have it?
What does ADHD mean for my child?
– Academic and social impact of ADHD
What does ADHD mean for my family?
– Challenges for parenting
Why is it important to seek help and
support?
– Lifespan perspective of untreated ADHD
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TeachADHD/Singapore/2007
What is Attention-Deficit/Hyperactivity
Disorder (ADHD)?
It is a medical term
given to children
(adolescents, adults), who exhibit a
persistent , developmentally
inappropriate, and impairing pattern of
behavior, such as…
– Problems paying attention, distractible
– Interrupting and intruding upon others
– Fidgeting, squirming in seat
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TeachADHD/Singapore/2007
ADHD: Medical definition
Attention-Deficit/Hyperactivity Disorder
(ADHD) is a neurobiological condition that
becomes apparent in the preschool and
early school years
Main Characteristics:
Inattention
Hyperactivity
Impulsivity
: An
Neurobiological disorder
illness of the nervous
etic,
system caused by gen
ctors.
metabolic, biological fa
Many ‘mental’l’ health
problems are
,
neurobiological (ADHD
autism, schizophrenia)
Characteristics of a child with ADHD
• Often moves more quickly into a state of high agitation or
excitement than other children
• Often talks incessantly and loudly, is constantly moving, and
frequently switches from one activity to another without
pause
• Cannot filter out unimportant stimuli – everything grabs his
or her attention
• Annoys everybody and cannot help it
• Is disliked by others and may realise this
• Has low self-esteem and often dislikes himself/herself
• Is often remorseful after behaving ‘badly’, saying ‘I can’t
help it’
• Demonstrates this behaviour in a persistent and enduring
way
ADHD is very common!
5.27% children &
adolescents, worldwide
1-2 students per class
4% adults
Male: female ~ 3:1
[but in adults ~ 1:1]
Skounti et al (2007) Eur J Pediatr. 166(2):117-23. .
Faraone et al (2003) World Psychiatry 2:104-113; Kessler et al (2005) Arch Gen Psychiatry 62:617-627
ADHD has been recognized in medicine
for a long time!
“Fidgety Phil”
“Johnny-Head-InThe-Air”
1845
Dr. Heinrich Hoffman
“a
defect of moral control
- of biological origin”
1902
Dr. George Still
TeachADHD/Singapore/2007
ADHD is a ‘hidden’ disability
Individuals with ADHD do not look
different, but they behave differently:
– Do not respond to typical parenting & so
make family life quite stressful
– Do not respond to typical classroom
management and so may disrupt the class
and interfere with the process of teaching
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2 clusters of behavioral symptoms
3 subtypes of ADHD
INATTENTIVE
SUBTYPE
INATTENTION
“ADD”
HYPERACTIVEHYPERACTIVITYIMPULSIVE
SUBTYPE
IMPULSIVITY
COMBINED TYPE
“Classic ADHD”
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TeachADHD/Singapore/2007
Inattention
Hyperactivity Impulsivity
Easily
sidetracked &
unable to filter
out distractions
Inability to
concentrate
Inability to sit
through a
lesson
Disorganized
& forgetful
Constant
fidgeting,
fiddling
Acting before
thinking
Inability to
Roaming
around a room wait one’s turn
Butting in and
interfering
with others
Attention Problems: at least 6 of 9 symptoms
1. Poor attention to details, makes
careless mistakes
2. Difficulty concentrating
3. Doesn’t seem to listen
4. Fails to follow through on instructions &
finish work
5. Difficulty organizing work and self
6. Avoids, dislikes lengthy, effortful tasks
7. Loses things
Persistent (> 6 months)
8. Easily distracted
Pervasive (> one setting)
9. Forgetful
Impairing
Manifestation of ADHD symptoms of
inattention in school
• Difficulty organizing
work & self
• Papers misfiled or pushed
into bag; locker, desk,
backpack in constant disarray
• Easily distracted
• Constantly looking around at
what others are doing or what
is going on; head on a swivel;
activity or noises in
classroom pull student away
from work
• Frequently loses things
• Constantly hunting for
needed items (pencil, book
etc)
Hyperactivity/Impulsivity problems
at least 6 of 9 symptoms
Hyperactivity
1. Fidgets, squirmy
2. Leaves seat
inappropriately
3. excessive running,
climbing
4. difficulty playing
quietly
5. on the go, driven
6. talks excessively
Impulsiveness
7. blurts out
8. can’t wait turn
9. interrupts, intrudes
Persistent (> 6 months)
Pervasive (> one setting)
Impairing
Manifestation of ADHD symptoms of
hyperactivity/impulsivity in school
• Constantly on the go • Frequently rocks chair,
• Difficulty remaining
seated (when it is
expected)
stands up or leans over desk,
swings legs, shifts in seat,
rarely stops moving
• Wanders around classroom;
frequently stands instead of
sitting at desk
• Difficulty awaiting turn • Does not wait to be called on
but shouts out answer; gets
frustrated & disruptive when
has to wait in line
ADHD differs in boys and girls
(Abikoff et al., 2002; Biederman et al., 2002; Rucklidge & Tannock,
Tannock, 2002; Tannock,
Tannock, 2004)
Girls are :
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less likely to exhibit disruptive behavioral
symptoms of ADHD
as likely to exhibit covert symptoms of ADHD
as impaired cognitively, academically,
socially
more likely to exhibit covert, verbal
aggression
TeachADHD/Singapore/2007
ADHD persists into adolescence &
adulthood: but changes in its behavioral
manifestation
Impul
Hyp sivity
erac
tivit
y
Diagnostic level
Sub-threshold but
impairing levels
Normal levels
childhood
adolescence
adulthood
50%-75% cases
50-75% cases
TeachADHD/Iceland/2006
ADHD looks somewhat different
in adolescents
Inner mental restlessness, rather than
observable high activity
– Tend to want to be constantly doing something
Disorganization, poor time management &
problems concentrating
– Rarely has books, materials needed for class
– Major problems with completing assignments on
time
– Great difficulty listening to and taking notes during
a lecture
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Symptoms vary within a child
minute-to-minute, day-to-day, &
from one situation to another
Symptoms increase during
activities with:
– high cognitive demand
– little active engagement
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ADHD look-alikes
Many children experience behavioural
symptoms of ADHD for reasons other
than ADHD
– stressful or worrying events
– Dyslexia or other specific LD
– Brain injury, FAS, language weaknesses
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Doctors “rule-out” other medical
explanations before they confirm that
the problems are due to ADHD
TeachADHD/Singapore/2007
ADHD – Why does my child have it?
Is it my fault?
Is it because of my parenting?
Is it too much sugar or junk food?
Is it because my child is just naughty or lazy?
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TeachADHD/Singapore/2007
ADHD:
It is nobody’s fault!
It is not shameful for the family or child
It is often inherited
– runs in families –
just like height, vision problems,
dyslexia
But it makes life tough for the individual
with ADHD and the family!
So seek help!
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What causes ADHD?
Multiple factors but we don’t know how
they fit together!
Neuroanatomic
Neurochemical1
Genetic
origins
2-4
ADHD
Environmental
factors3,5
1. Swanson J, et al. Curr Opin Neurob iol 1998; 8:263271.
2. Hauser P, et al. N Engl J Med 1993; 328:997-1001.
3. Swanson JM, et al. Mol Psychiatry 1998; 3:38-41.
CNS
insults5,6
4.Swanson JM, et al. Lancet 1998; 351:429-433.
5. Milberger S, et al. Biol Psychiatry 1997; 41:65-75.
6. Castellanos FX, et al. Arch Gen Psychiatry 1996;
53:607-616.
ADHD is heritable & runs in families
Highly heritable
Average genetic contribution of ADHD
based on twin studies = 0.8 (Asthma = 0.4)
Faraone. J Am Acad Child Adolesc Psychiatry. 2000;39:1455-1457
If one child in family has ADHD, often
one of the other siblings has ADHD
Biederman et al: Arch Gen Psychiatry 1992; 49:72838
If a child has ADHD, often one of the parent
has ADHD
Faraone & Biederman:
Biederman: Harvard Rev Psychiatry 1994; 1:271-87
Chronis et al: JAACAP 2003, 42:1424-1432
Tannock/OASAR/April 2006
ADHD
Hyperactivity
Impulsivity
Inattention
Behavior symptoms of ADHD are just the tip of the iceberg!
TeachADHD/Singapore/2007
Brain structure & function in ADHD
Castellanos et al: JAMA 2002; Durston et al., JAACAP 2004; review by Tannock 1998)
Overall brain volume
3% smaller in ADHD
Decreased prefrontal
volume & activation
(particularly R hemisphere)
Smaller R cerebellar
volume & smaller
vermis lobules VII-X
[corrected for brain size]
Adapted from Castellanos: ACNP 2002
TeachADHD/Singapore/2007
Brain differences in ADHD occur in regions that are
important for attention, self-regulation, and learning
Frontal lobe: control attention & resist
distraction.
Parietal lobe: visual-spatial
information
Cerebellum: exact timing &
coordinating movement
other areas:
Corpus callosum: exchanges
information between brain’s
hemispheres
Corpus striatum: motor control
& reward mechanisms
TeachADHD/Singapore/2007
R. Tannock: HSC Toronto/ Public Education Program:
Kelowna, British Columbia (Nov 2005)
Environmental factors in ADHD
Prenatal exposure to nicotine
– Maternal smoking, second-hand exposure
Prenatal exposure to other neurotoxins
– Lead, poly-biphenyls, etc
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Prematurity
TeachADHD/Singapore/2007
ADHD Is Not Usually Caused by:
too much TV
food allergies
excess sugar
food additives
NOR BY
parents or poor home
life
Teachers or poor
schools
TeachADHD/Singapore/2007
ADHD and sleep
Sleep problems and ADHD:
Students with ADHD
complain
or tiredness during day
Often
have difficulties falling asleep at night & waking
up in the morning
Poor / inadequate sleep impairs attention and
performance in every one
No clear evidence that sleep problems cause ADHD
Stevens & Mulsow (2006) Pediatrics 117:665-72; Obel et al (2004) Pediatrics: 144: 1372-73
Bateman et al (2004) Arch Dis Child 89:506-11; Weiss et al (2006) JAACAP 45:512-9
TeachADHD/Singapore/2007