1	ADHD and Executive Functions: Impact of Learning & Life Thomas E. Brown, PhD Associate Director, Yale Clinic for Attention and Related Disorders Department of Psychiatry Yale Medical School
2	Shifts in Conceptualizing ADHD 1968 Hyperkinetic Disorder of childhood 1980 Attention Deficit Disorder 1987 ADHD (only combined symptoms) 1994 AD/HD–3 types 2000 AD/HD (impaired executive function)
3	Prevalence and Genetics of ADHD 6-8% of children; 3-4% of adults Male-female: 6:1, 3:1, 1:1 All levels of IQ All levels of socioeconomic status Family genetic transmission: 0.87 Inheritance not specific to subtype
4	DSM-IV Hyper-Impulsive Restless feelings and actions impulsive actions and speaking out excessive impatience only 2 speeds: full or asleep very difficult to relax intrusive impaired ability to inhibit
5	DSM-IV Inattention Attending to work task organizing work sustaining mental effort task completion filtering distractions short-term memory “motivated to work”
6	“Executive Functions” (EF) Wide range of central control processes of the brain Connect, prioritize, and integrate cognitive functions–moment by moment Like conductor of a symphony orchestra
7	“Focus” and Executive Function Impairments of ADHD In DSM-IV “inattention” symptoms of ADHD Do not mean Unable to focus as in holding the camera still to take a photo of an unmoving object Do mean Unable to focus as in focusing on the task of driving a car
8	EF Development and Demands EF capacity develops through childhood, into adolescence and beyond; it is not fully present in early childhood Environmental demands for EF increase with age, from preschool through adulthood EF impairments often are not noticeable by age 7!
9	Executive Functions and Scaffolding In early childhood, others perform all executive functions for the child (parents, teachers, sibs and other caretakers) Scaffolding is provided by showing, directing, helping, reminding, coaching, critiquing (Examples: walking, getting dressed, crossing street, riding bike, driving car) Scaffolding is gradually withdrawn, as child becomes able to (or is forced to) perform these functions for self In adolescence & adulthood scaffolding may be provided by: friends, teachers, coaches, spouses, supervisors
10	How Can Executive Functions Become Impaired? Developmentally, eg, ADHD Trauma, eg, traumatic brain injury Disease, eg, Alzheimer’s disease In trauma and disease, the patient usually has had adequate EF, then loses it In ADHD, EF has not developed adequately
11	What is ADHD? (A Controversial Viewpoint) ADHD (all subtypes) = Developmental Impairment of Executive Functions Developmental Impairment = (Not emerging and unfolding as expected for age)
12	Characteristics of ADHD Symptoms Dimensional, not “all-or-nothing” Everyone sometimes has some impairments in these functions; in ADHD: chronic, severe impairment Situational variability: “If I’m interested” Most persons with ADHD have a few activities where ADHD impairments are absent
13	Brown’s Model of Executive Functions Impaired in ADHD
14	1.Organize, Prioritize & Activate trouble getting started on work difficulty organizing tasks misunderstands directions (Brown, 1995, 2000, 2001)
15	2. Focus, Shift & Sustain Attention loses focus when trying to listen or plan forgets what was read, needs to re-read easily distracted-internal/external (Brown, 1995, 2000, 2001)
16	3. Regulating Alertness, Effort & Processing Speed difficulty regulating sleep & alertness quickly loses interest in task, especially longer projects; doesn’t sustain effort difficult to complete task on time, especially in writing-- “slow modem” (Brown, 1995, 2000, 2001)
17	4. Manage Frustration, Modulate Emotion (not included in DSM-IV criteria) emotions impact thoughts, actions too much “can’t put it to the back of my mind” overreacts to frustration, hurts or worries (Brown, 1995, 2000, 2001)
18	5. Utilize Working Memory Access Recall Forgets to do planned tasks Difficulty recalling learned material loses track of papers, belongings (Brown, 1995, 2000, 2001)
19	6. Monitor and Self-Regulate Action Hard to sit still or be quiet does tasks too fast, not careful enough often butts in or interrupts (Brown, 1999, 2000. 2001)
20	When Are ADHD Impairments Noticeable? Some are obvious very early and are noticeable in preschool years Some are not noticeable until middle elementary or junior high Some are not apparent until child leaves home to go to college or later
21	A Chemical Problem ADHD is fundamentally a chemical problem Most effective treatment is to change the chemistry with medication Unless the problematic chemistry is changed, other interventions are not likely to be very effective
22	In the Human Brain 100 billion neurons each one linked to >1000 others in complex sub-systems that have to “talk to each other” using low voltage electrical impulses that have to jump across gaps so fast that 12 can cross in 1/1000 sec.
23
24
25	Chemicals Jump the Gaps Inside brain >50 different chemicals are continuously made every neuron system uses 1 of them stored in little vesicles near tip of neuron when electrical impulse comes, mini-dots of that chemical are released, cross the gap, fire next neuron, then reload in fractions of a second
26
27
28
29
30
31
32	2 crucial chemicals: (dopamine, noripinephrine) control most of functions impaired in ADHD Brain of person with ADHD makes these chemicals, as does everyone else but does not release & reload effectivelyà control messages often not connecting For 80% of those with ADHD medications improve this problem.
33	How do ADHD Impairments of EF Usually Respond to Medication? This wide range of cognitive impairments responds to medication treatment in 70-90% of cases in children, adolescents and adults Symptom improvement varies from modest to very dramatic Adverse effects are usually transient, not significant
34	Safety of ADHD Medications American Medical Assn. Report “More than 170 studies involving >6,000 children using stimulant medications for ADHD…up to 90% will respond to at least 1 stimulant without major adverse events if drug titration is done carefully “ Adverse effects from stimulants are generally mild, short-lived, & responsive to dosing or timing adjustments” (Goldman, et. al., 1998, pp 1103-1104)
35	Substance Abuse Associated With ADHD Risk of developing SUD over lifetime is 52% for adults with ADHD vs 27% In ADHD, substance-use disorders onset earlier, last longer, & remit more slowly If ADHD is appropriately treated with stimulant medications in childhood and adolescence, risk of SUD reduced 84% Wilens, Farone, Biederman, et al, Pediatrics, 2003)
36	ADHD Is a Complex Disorder Often Complicated by Comorbidity In 50-70% of cases, ADHD is further complicated by one or more additional psychiatric or learning disorders Not only is it possible to have another disorder with ADHD, it is 6 times more likely in lifetime than for those without ADHD
37
38	Psychiatric Comorbidities in adults with ADHD 12 mo. Lifetime % OR % OR Any mood 25.5 3.5 45.4 3.0 Any anxiety 47.0 3.4 59.0 3.2 Any substance 14.7 2.8 35.8 2.8 Any impulse¹ 35.0 5.6 69.8 5.9 Any psychiatric 66.9 4.2 88.6 6.3 ⁽¹impulse ⁼ antisocial pd, ODD, CD, Intermittent explosive disorder, bulimia, gambling (from National Comobidity Survey-Replication data presented by R.Kessler at APA, 5/1/04)
39	PUZZLING QUESTIONS! Why are there such high rates of comorbidity between ADHD and so many other disorders? Why is an adult with ADHD 6 times more likely to have at least one additional DSM-IV disorder at some point in life?
40	LD in ADHD Reading LD 27% Math LD 31% Written Expression LD 65% One or more LD 70% (Mayes, Calhoun, Crowell, 2000)
41	ADHD vs LD Separate entities? Some think: ADHD = chemical problem in brain LD = “hard-wiring” problem in brain Current research suggests that ADHD and LD may not be so separate Evidence suggests shared genetic etiology in Reading Disorder and ADHD (Willcutt, Pennington & DeFries, 2000)
42	Working Memory plays crucial role in: Reading -learning to read-integrating fragments -recalling & comprehending Math -recall of facts and procedures -computation & problem-solving Written Expression -organizing & elaborating
43	How Is ADHD Related to Comorbid Disorders? ADHD: developmental impairment of executive functions that organize and regulate many specific functions of the mind c.f.: impaired orchestra conductor Comorbidity: ADHD with 1 or more specific mental functions also impaired c.f.: orchestra player(s) + conductor impaired
44	Exec Function Impairments Characterize Most Diagnoses
45	Key Points not a unitary disorder developmental, heritable dimensional, not categorical impairments of executive functions not always linked to hyperactivity implicated in many psychiatric disorders often responsive to medication treatments
46	Websites and Email chadd.org (in English and Spanish) add.org (mostly adults with ADHD) adders.org (in Eng, Span, Ger, French with listings of support groups in 40 countries) my Website: www.DrThomasEBrown.com