ADHD??!!!?!

1. ADHD??!!!?!

2. Relationship between ADHD and EF EF  ADHD All ADHD have some EFD but All EFD not ADHD

3. ADHD 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

4. Provocative 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?

5. Provocative Question #2Should we reconceptualize and redefine the syndrome now known as ADHD in terms of the neuropsychological construct of Executive Function?

6. Provocative Question #3Should the executive function deficits associated with ADHD be addressed directly in educational programming?

7. Attention-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

9. Attention-Deficit/Hyperactivity Disorder (ADHD): DSM-IV Diagnostic Criteria • (2) 6 or more symptoms of hyperactivity-impulsivity • 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

12. Rule Outs • TBI • Epilepsy • Language processing disorders • Anxiety disorders including PTSD • Depression • Chaotic environment • Sleep disorders

13. Clinical Symptoms of ADHD • Beyond the traditional triad of “not paying attention”, “not thinking before he acts” and “running all over the house constantly”...

14. Clinical Symptoms of ADHDCore or not? • … Reports of “Disorganization, can’t remember 3-step instructions, poor planning, not checking his/ her work, difficulty accepting other strategies, getting stuck, overemotional, locker/ notebook looks like a disaster...”

15. Clinical 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?

16. Evolution 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”

17. Evolution 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) • ???

18. Recent 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.

19. Models 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

20. Barkley (Bronowski) EF Model Behavioral Inhibition Working Memory (nonverbal) Internalization of speech (verbal working memory) Self-regulation of affect/ motiv./ arousal Reconstitution (analysis, synthesis, goal-directed) Motor control/ fluency/syntax

21. Barkley (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.

22. Barkley (Bronowski) EF Model • Reconstitution - analysis combining with synthesis, allowing manipulation to synthesize new responses. Allows flexible, fluent, inventive goal-directed behaviors.

23. General 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.

24. General Conclusions • Multidimensionality of Executive Function provides a more comprehensive yet more specific model of ADHD, incorporating a more full set of relevant symptom behaviors.

26. Brain Basis for the Executive Functions

27. Proportional size of prefrontal region • Human 29% • Chimpanzee 17% • Gibbon/Macaque 11.5% • Lemur 8.5% • Dog 7% • Cat 3.5%

28. Neuroanatomic 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

29. 3 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 <----> Complimentary Relationship

30. 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 Lateral Axis <-->

31. Cortical-Subcortical Cortical (Thinking) Systems Frontal System Modulation Inhibition and selection Subcortical Systems Retic. Activ SystMotor ControlEmotions/Drive -Arousal - Impulses -Alertness - Emotional/Social Drives

32. Neuroanatomic 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

33. Central 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)

34. Frontal system versus frontal lobe • Frontal system acknowledges & incorporates interconnectedness • A disorder within any componentof the frontal system network can result in executive dysfunction

35. Conditions 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.

37. Neuroanatomy “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)