Title: ADHD??!!!?!
1ADHD??!!!?!
2Relationship between ADHD and EF
- EF ? ADHD
- All ADHD have some EFD but
- All EFD not ADHD
3ADHD and EF
- The two are not the same stem from different
descriptive systems - ADHD is a diagnosis based on cluster of observed
behaviors - EF is a neuropsychological construct
- Both describe a regulatory phenomenon
4Provocative Question 1Is the traditional triad
of symptoms (Inattention, Impulsivity,
Hyperactivity) sufficient to describe the full
set of treatable symptomatology in the syndrome
currently known as ADHD?
5Provocative Question 2Should we
reconceptualize and redefine the syndrome now
known as ADHD in terms of the neuropsychological
construct of Executive Function?
6Provocative Question 3Should the executive
function deficits associated with ADHD be
addressed directly in educational programming?
7Attention-Deficit/Hyperactivity Disorder (ADHD)
DSM-IV Diagnostic Criteria
- A. Either (1) or (2)
- (1) 6 or more symptoms of Inattention have
persisted for at least 6 months - often fails to give close attention to details or
makes careless mistakes in schoolwork, work, or
other activities - often has difficulty sustaining attention in
tasks or play activities - often does not seem to listen when spoken to
directly
8 - often does not follow-through on instructions and
fails to finish schoolwork, chores, or duties in
the workplace (not due to oppositional behavior
or failure to understand the instructions) - often has difficulty organizing tasks and
activities - often avoids, dislikes or is reluctant to engage
in tasks that require sustained mental effort - often loses things necessary for tasks or
activities (toys, school assignments) - is often easily distracted by extraneous stimuli
- is often forgetful in daily activities
9Attention-Deficit/Hyperactivity Disorder (ADHD)
DSM-IV Diagnostic Criteria
- (2) 6 or more symptoms of hyperactivity-impulsiv
ity - Hyperactivity (6)
- often fidgets with hands or feet or squirms in
seat - often leaves seat in classroom or in other
situations in which remaining seated is expected - often runs about or climbs excessively in
situations in which it is inappropriate - often has difficulty playing or engaging in
leisure activities quietly - is often on the go or acts as if driven by a
motor - often talks excessively
10- Impulsivity (3)
- often blurts out answers before questions have
been completed - often has difficulty awaiting turn
- often interrupts or intrudes on
11(Sub)types
- 1. ADHD, Combined Type A1 and A2 met for past
6 months - 2. ADHD, Predominantly Inattentive Type A1 met
but not A2 - 3. ADHD, Predominantly Hyperactive-Impulsive
Type A2 but not A1
12Rule Outs
- TBI
- Epilepsy
- Language processing disorders
- Anxiety disorders including PTSD
- Depression
- Chaotic environment
- Sleep disorders
13Clinical Symptoms of ADHD
- Beyond the traditional triad of not paying
attention, not thinking before he acts and
running all over the house constantly...
14Clinical Symptoms of ADHDCore or not?
- Reports of Disorganization, cant remember
3-step instructions, poor planning, not checking
his/ her work, difficulty accepting other
strategies, getting stuck, overemotional, locker/
notebook looks like a disaster...
15Clinical Symptoms of ADHDCore or not?
- Executive Function (EF) is largely implicit in
the DSM-IV diagnosis of ADHD. - Only Inhibit (Impulse Control) is explicit.
- Should EF be formally incorporated into theories
and definitions of ADHD? - Are formal assessment and treatment of these
(core?) EF symptoms necessary?
16Evolution of Diagnosis of ADHD
- 1st clinical description British physician Still
(1902) - deficit in volitional inhibition,
defect in moral control - Similarities to brain-injured child syndrome
(Strauss Lehtinen, 1947) but without evidence
of brain injury resulted in minimal brain
damage - Minimal brain dysfunction
- Hyperkinetic impulse disorder
- Hyperactive child syndrome
17Evolution of Diagnosis of ADHD
- Hyperkinetic reaction of childhood (DSM-II)
- first mention of inattention and distractibility
- Attention-deficit disorder (Douglas) (DSM-III)
- with and without hyperactivity
- Attention-Deficit/ Hyperactivity Disorder
(DSM-III-R) (no with or without) - Attention-Deficit/ Hyperactivity Disorder
(DSM-IV) (3 subtypes) - ???
18Recent Conceptualizations
- With a better understanding of brain-behavior
relationships, particularly the frontal lobes - ADHD is undergoing further redefinition in terms
of a disorder of the executive functions (EF)
(Barkley, 1997, 2000 Brown, 1999 Denckla, 1996
Pennington Ozonoff, 1996) - The primacy of attention is being questioned.
19Models of executive function in ADHD
- Pennington Ozonoff (1996)
- frontal metaphor deficits in inhibition and
working memory tasks - Barkley (1997, 2000)
- Inhibition as core, executive function as model
- Bayliss Roodenrys (2000)
- supervisory attentional system as executive
function
20Barkley (Bronowski) EF Model
Behavioral Inhibition
Working Memory (nonverbal)
Self-regulation of affect/ motiv./ arousal
Internalization of speech (verbal working memory)
Reconstitution (analysis, synthesis,
goal-directed)
Motor control/ fluency/syntax
21Barkley (Bronowski) EF Model
- Nonverbal working memory - visual imagery and
private audition internalized resensing. - Verbal working memory - covert language that
controls self rule-governed behavior. - Internalized emotion/ motivation - with working
memory, emotional control and motivation can
occur. Covert affective states. Source of
intrinsic motivation that drives future behavior.
22Barkley (Bronowski) EF Model
- Reconstitution - analysis combining with
synthesis, allowing manipulation to synthesize
new responses. Allows flexible, fluent,
inventive goal-directed behaviors.
23General Conclusions
- Relationship between EF and ADHD hypothesized by
Barkley (1997, 2000) and Pennington Ozonoff
(1996) is given strong support by BRIEF findings - Multidimensional construct of EF appears to
define with greater specificity the symptoms of
ADHD.
24General Conclusions
- Multidimensionality of Executive Function
provides a more comprehensive yet more specific
model of ADHD, incorporating a more full set of
relevant symptom behaviors.
25(No Transcript)
26Brain Basis for the Executive Functions
27Proportional size of prefrontal region
- Human 29
- Chimpanzee 17
- Gibbon/Macaque 11.5
- Lemur 8.5
- Dog 7
- Cat 3.5
28Neuroanatomic Organization
- Executive function neurological development
are parallel - Development of prefrontal cortex is central
- Frontal lobe damage can result in dysfunction of
various executive subdomains - BUT - Executive functions do not simply reside in
the frontal lobes
293 Neuroanatomic Axes andNeuropsychological
Function
- Anterior-Posterior Axis
- Anterior Systems ?-----? Posterior Systems
- Anticipates behavior - Receives information
- Selects Goals - Encodes
- Organizes/ Plans - Stores
- Orchestrates - Structure/ organization
- Monitors of Knowledge Base
- Modulates
- lt----gt Complimentary Relationship
30Lateral Axis
- Left Hemisphere Systems
- Preferentially involved with
- Building blocks of language
- Parts of complex materials
- Temporal processing
- Processing unimodal codable information
- Executive of discrete motor
- Right Hemisphere Systems
- Preferentially involved with
- Spatial information
- Relationship between parts
- Configuration of complex
- Processing multi-modal novel information
- Emotional tone in speech
lt--gt
31Cortical-Subcortical
- Cortical (Thinking) Systems
- Frontal System Modulation
- Inhibition and selection
- Subcortical Systems
- Retic. Activ Syst Motor Control
Emotions/Drive - -Arousal - Impulses
- -Alertness - Emotional/Social
- Drives
32Neuroanatomic Organization
- Frontal lobes are densely connected with other
cortical and subcortical regions - Prefrontal system is highly, reciprocally
interconnected with the - limbic (motivational) system,
- reticular activating (arousal) system
- posterior association cortex (perceptual/
cognitive processes and knowledge base) - motor (action) regions of the frontal lobes
33Central neuroanatomic position underlies
regulatory control over
- Perceptual coding in posterior/temporal isotypic
regions - Conceptual processes of the posterior association
cortex - Attentional functions supported by subcortex
(reticular activating system) - Emotional functions subserved by subcortex
(limbic system)
34Frontal system versus frontal lobe
- Frontal system acknowledges incorporates
interconnectedness - A disorder within any component of the frontal
system network can result in executive dysfunction
35Conditions that render the frontal systems
vulnerable include
- Connectivity disorders such as cranial radiation
and white matter development (migration errors) - Lead poisoning affecting synaptogenesis
- Direct prefrontal trauma in traumatic brain
injury - Dysfunctional neurotransmitters (e.g., dopamine
in TS ADHD) - Posterior cortex disorders including LD
- Arousal mechanism disorders in TBI (shearing),
severe depression.
36- Executive dysfunction can arise from damage to
the primary frontal regions as well as to the
densely interconnected secondary posterior or
subcortical areas. The associated cognitive
partners and slave systems must be present in
order for the executive regulatory functions to
have any operational purpose.
37Neuroanatomy
- Executive Function is a convenient shorthand
that captures the problems of a group of
patients...The levels should be kept separate
Executive function should not be confounded with
prefrontal except at a hypothesis-generating
level. (Denckla, 1996)