1. Attention Deficit Hyperactivity Disorder
James H. Johnson, Ph.D., ABPP
University of Florida

2. ADHD: Nature of the Problem
ADHD is a neurodevelopmental disorder of childhood that is characterized by developmentally inappropriate levels of:
Hyperactivity,
Impulsivity,
Inattention.

3. ADHD: How Common is it?
Prevalence is estimated at 3 to 9 per cent of the elementary school population.
ADHD occurs more often in males than females, with the sex ratio being about 4 to 1 to 9 to 1.
It is one of the most common disorders of childhood
Accounts for a large number of referrals to pediatricians, family physicians and child mental health professionals.

4. ADHD: Not a New Problem
Characteristics of this disorder have been recognized for at least a century.
The disorder has been referred to by a variety of labels;
Minimal Brain Dysfunction (MBD)
Hyperkinetic Reaction of Childhood
Attention Deficit Disorder (ADD)
Attention Deficit Hyperactivity Disorder (ADHD)

5. ADHD: Evolution of the Disorder
Still (1902): ADHD Case study
Encephalitis epidemic of 1917
Frontal lobe ablation studies with primates (1930’s)
Strauss’ work on Minimal Brain Dysfunction (1940's -1950's)
Beginnings of child psychopharmacology; Using Amphetamines for treatment –
MBD becomes Hyperkinetic Disorder (the 1960’s)

6. ADHD: Evolution of the Disorder (cont.)
Hyperkinesis becomes ADD – The decade of the 70’s
Focus on Dietary Factors – Feingold and the 1970’s
Studies of psychophysiological responses of hyperactive children – the 1970’s
Development of objective diagnostic criteria: DSM III
Recognition of Attention Deficit Disorder – The early 80’s

7. ADHD: Evolution of the Disorder (cont.)
The decade of the 80’s: DSM III & DSM III-R stimulates ADHD research and the development of new assessment methods – new treatment methods - increased focus on biological factors.
The 1990’s - Present: Neuroimaging, genetics and and a reevaluation of DSM.

8. ADHD: Core Features
As noted earlier, ADHD is a disorder characterized by developmentally inappropriate levels of :
Hyperactivity,
Impulsivity,
Inattention.

9. DSM IV Symptoms of Hyperactivity
Often fidgets with hands or feet, 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.

10. Hyperactive Symptoms
Is often "on the go" or often acts as if "driven by a motor“.
Often talks excessively when inappropriate to the situation
A combined total of 6 or more of hyperactivity/impulsivity criteria are required for diagnosis.

11. What do we Know about Hyperactivity?
Children with ADHD are more active, restless, and fidgety than normal children during the day and during sleep.
There are different types of hyperactivity.
Gross Motor Activity
Restless/Squirmy
Occasionally see verbal hyperactivity
Hyperactivity often varies according to situation.
Degree of hyperactivity may vary with age.

12. Symptoms of Impulsivity
Often blurts out answers before questions have been completed.
Often has difficulty awaiting turn.
Often interrupts or intrudes on others.
Six symptoms of hyperactivity and impulsivity are required for diagnosis.

13. Symptoms of Inattention
Often fails to give close attention to details or makes careless mistakes.
Often has difficulties sustaining attention in tasks or play activities.
Often does not seem to listen when spoken to directly.
Often does not follow through on instructions and fails to finish homework, chores, or duties in the workplace

14. Symptoms of Inattention
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
Is often easily distracted by extraneous stimuli.
Is often forgetful in daily activities
(6 or more necessary for diagnosis)

15. What Do We Know About ADHD Attention Problems?
ADHD "attentional" problems may be most obvious on specific types of attentional tasks.
Children with ADHD seem to have their greatest difficulties with sustaining their attention in responding to tasks - in being vigilant.
Attention problems are usually seen most clearly in situations requiring the child to attend over time to dull, boring, and repetitive tasks.

16. Situational Variations in Symptoms
ADHD symptoms show significant variation across situations.
Children with ADHD do not display symptoms in all situations
The absence of symptoms in some situations does not mean that the child does not have ADHD.

17. Situations That Increase ADHD Symptoms
When the demands of the situation are to be good, to be still, and to be quiet.
The greater the demands, the more problematic the behavior of the child will likely become.
An exception might be in situations where the child is being continuously rewarded for complying with demands.
In familiar situations where novelty and task stimulation are low.

18. Other Situations That Increase Symptoms
Situations where there are low rates of intrinsic or external reinforcement.
When the child is fatigued.
Studies, monitoring 24 hour activity levels have suggested that the hours of 1 – 5 seem to be peak times for increased activity in children with ADHD.

19. Overview of Diagnostic Criteria
Symptom Criteria - Core Symptoms of Hyperactivity & Impulsivity and/or Inattention (Six or More Symptoms of either category).
Duration Criterion - Symptoms have Persisted for at Least 6 Months.
Developmental Criterion - Symptoms are Inconsistent with Developmental Level.
Impairment Criterion - Clear Evidence of Clinically Significant Impairment in Social, Academic, or Occupational Functioning

20. Overview of Criteria (cont.)
Age Criterion - Some Symptoms that Cause Impairment Were Present Before Age 7.
Situation Criterion - Some Impairment from Symptoms is Present in Two or More Settings.
NOTE. The failure to attend to full range of symptoms is not uncommon
Presence of hyperactivity, impulsivity, and inattention is not necessarily to be equated with ADHD.

21. Types of ADHD Combined Type Hyperactive/Impulsive
Symptoms of hyperactivity, impulsivity and inattention.
Hyperactive/Impulsive
Symptoms of hyperactivity and impulsivity.
Predominately Inattentive
Symptoms of inattention.

22. ADHD Mimicry Sensory Impairments Medication side effects
Phenobarbital
Dilantin
Some Asthma Medications
Seizure Disorder
RTH (Resistance to Thyroid Hormone)
PTSD
Bipolar Disorder
Anxiety Disorders
Depressive Disorders

23. Comorbid Conditions What are comorbid conditions?
Controversy over use of the term.
Why is it essential to consider the possibility of comorbid conditions in assessing children with ADHD?
Importance of distinguishing between comorbid conditions and mimicry.
What is the frequency of comorbidities in children with ADHD?

24. Comorbid Conditions Learning Disabilities - 19 to 26%
Oppositional Defiant Disorder - 40% Conduct Disorder - 25% children; 45-50% Adolescents.
Anxiety Disorders - 30%
Depressive Disorder %
Bipolar Disorder – up to 20%.
Tics and Tourette’s Disorder – 7% of children with ADHD have a tic disorder.
40 to 50% of those with Tourette’s disorder have ADHD

25. Developmental Issues
There are factors in infancy, such as difficult temperament, that appear to be early precursors of ADHD.
Initial development of ADHD is most often during the preschool years.
While there is often a decline in the level of hyperactivity and some improvement in attention and impulse control in adolescence, perhaps 80 % continue to be impaired by their symptoms and meet current diagnostic criteria.
A significant number of children with ADHD (probably over 50%) continue to display problems into the adult years.

26. Prognosis of ADHD
Outcome of ADHD in adolescents is highlighted by the results of a study by Barkley, Fischer, et al, (1990).
This study followed a large sample of ADHD (158) and normal children (81) prospectively for 8 years after diagnosis.
123 hyperactive children and 66 normals were located, interviewed and complete questionnaires.
In the hyperactive group 12 (9.7%) were female and 111 were male. In the normal group 4 of the subjects were female and 62 were male.

27. Prognosis In Adolescence
The vast majority of the hyperactive subjects (71.5%) met DSM III-R criteria for ADHD at follow up.
More than 59% met criteria for Oppositional Defiant Disorder as compared to 11% of the controls.
 Approximately 43 % of the hyperactive group could be diagnosed as CD as compared to 1.6% of the control group.

28. Prognosis Continued
Hyperactive subjects were more likely to have had an auto accident, to have had more automobile accidents, to have had more bodily injuries in accidents, and to be at fault for accidents more often than did controls.
Adolescents in the hyperactive group were also more likely to have received traffic citations, especially for speeding

29. Prognosis Continued
Cigarette and alcohol use were the only categories of substance use that differentiated hyperactives and normals.
When the the hyperactive sample was separated into groups (purely ADHD and ADHD + CD) purely ADHD subjects showed no greater use of cigarettes, alcohol, or marijuana than did normal controls.
Mixed hyperactive/Conduct disordered children displayed two to five times the rate of substance use as did pure hyperactives or normals.

30. Prognosis Continued
Three times as many hyperactives had failed a grade (29.3% versus 10%), had been suspended (46.3% versus 15.2%) or had been expelled (10.6% versus 1.5%).
Results indicated that hyperactivity alone increases the risk of suspension (30.6% vs 15.2%), and dropping out
(4.8% vs 0% ) as compared to controls
However, the added diagnosis of CD greatly increases the risk (67% suspended, 13% dropped out).
The presence of CD accounted almost entirely for the > risk of expulsion within the hyperactive group

31. Prognosis In Adulthood
As many as 67% of children diagnosed with ADHD will display symptoms in adulthood serious enough to interfere with academic, vocational or social functioning.
There are indications that the type of ADHD that persists into adulthood is more highly genetic than the type that remits in childhood.
ADHD in adults is sometimes considered a “hidden disorder” as symptoms are often obscured by other problems.
Prevalence is thought to be 2 – 4% with sex ratio of 2 – 1 or lower).

32. Risk Factors Maternal cigarette use Maternal alcohol use
Unusually long or short labor
Forceps delivery
Toxemia
Meconium staining
Birth during the month of September.
Minor physical anomalies

33. Etiology - Genetics
Between 10 and 35 per-cent of the immediate family members of children with ADHD also display this disorder.
 Risk for siblings of children with disorder is approximately 32%
If a parent has ADHD the risk to offspring is on the order of 50+%
Twin studies suggest concordance rates for monozygotic twins is around 80% with concordance rates of approximately 30% for dizygotic twins.
Overall, twin studies suggest an average heritability of .80

34. Etiology: Molecular Genetics
Molecular genetics has begun to identify specific genes related to ADHD.
A “dopamine type 2 gene” has been found to be related to ADHD as well as Tourette’s and alcoholism.
More recently a "dopamine transporter gene" and a “dopamine repeater gene”have been identified.
This gene, found to be related to ADHD in multiple studies, seems to be related to post-synaptic sensitivity in the frontal and prefrontal cortical regions and to be associated with executive functions.

35. Genetic Contributions (cont.)
With developments in molecular genetics occurring at an increasingly rapid rate (due to the Human Genome Project), in the near future, we may have genetic tests that can provide early screening for ADHD and possibly associated comorbidities.
Genetic factors are clearly strongly implicated in the development of this disorder.
Hereditary is one of the most well supported etiological factors in the development of ADHD

36. Etiology – Neurological Insult
Multiple factors that can result in brain damage are associated with ADHD.
For example, anoxia, is associated with increased frequencies of hyperactivity and attentional problems.
ADHD occurs more often in children with seizure disorders, who are presumed to have neurological involvement
As was noted earlier, diseases such as encephalitis can also result in symptoms of ADHD as can various types of infections.

37. Etiology: Brain Damage
These findings suggest that neurological insult can result in an increased probability of developing ADHD.
However, most children with ADHD do not have a significant history of brain injury.
Indeed, such injuries are unlikely to account for ADHD in most children.
In fact probably 95% of hyperactive children show no evidence of documentable neurological impairment.
This does not mean, however, that neurological factors are not involved.

38. Neuropsychological Test Findings
Results from research involving neuropsychological testing has often suggested that children with ADHD have problems;
in inhibiting behavioral responses,
with working memory,
with planning and organization,
with verbal fluency,
with perserveration,
In motor sequencing,
with other frontal lobe functions.

39. Research with Neuropsychological Testing (Cont.)
Not only do children with ADHD show executive functioning deficits but siblings of ADHD children who do not have ADHD, have milder yet significant impairments of the same type.
This suggests a possible genetic risk for executive function deficits in families.

40. Cerebral Blood Flow
Studies of cerebral blood flow in ADHD and normal children have consistently shown decreased blood flow to the prefrontal regions and pathways connecting these regions to the limbic system via the striatum and specifically its anterior region (the Caudate Nucleus)
Studies using PET scans to assess cerebral glucose metabolism in the frontal regions have found diminished metabolism in, adults and adolescent females with ADHD.

41. Cerebral Blood Flow Continued
Significant correlation's between diminished metabolic activity in the left anterior frontal region and severity of symptoms in adolescents with ADHD have also been demonstrated
This demonstration of a relationship between decreased metabolic activity of certain brain regions and severity of ADHD symptoms is crucial to documenting the importance of the link between brain activation and behaviors associated with ADHD

42. Frontal Lobes

43. Basal Ganglia

44. Striatal Network

45. MRI Studies
Early studies found differences in the Corpus Callosum, with this structure being smaller in children with ADHD. – Not always replicated.
Other MRI studies have found children with ADHD to have a smaller left caudate nucleus than did normal children. These findings are interesting in light of the results of earlier blood flow studies suggesting lower levels of activation in this specific area in children with ADHD.

46. MRI Continued
Several more recent MRI studies, with larger samples, have replicated these early results by finding that ADHD children had significantly smaller anterior right frontal regions, a smaller caudate nucleus, and smaller golbus pallidus regions that normals.
Research has also found decreased cerebellar volume in ADHD children.
Work in this area suggests that abnormalities in the development of the frontal-striatal regions may well underlie the development of ADHD.

47. Neurotransmitter Deficiencies
The possibility of a neurotransmitter dysfunction in children with ADHD has been suggested for many years.
This notion seemed to originate from observations of the response of children with ADHD to different type of stimulant drugs.
The fact that stimulant drugs have an impact on ADHD and that they increase dopamine has contributed to the neurotransmitter dysfunction hypothesis.

48. Neurotransmitter Deficiencies
There is more direct evidence of neurotransmitter deficiencies from studies of cerebral spinal fluid in ADHD and normal children which suggests decreased dopamine levels in ADHD children
There is also some evidence of a deficiency in the availability of norepinephrine in children with ADHD.
This is of interest given that a very new non-stimulant ADHD medication, Straterra, is thought to act on norepinephrine levels.

49. Etiology: Psychosocial Factors
There is little evidence for the role of psychosocial factors in the development of ADHD, although factors such as parent-child conflict may exacerbate problems in a child with ADHD.
Psychosocial factors may also contribute to the development of certain comorbid disorders that may complicate the clinical picture.

50. Etiology: Overview
In reviewing the literature on the etiology of ADHD, Barkley suggests …
“It should be evident from the research…that neurological and genetic factors make a substantial contribution to symptoms of ADHD and the occurrence of this disorder.
A variety of genetic and neurological etiologies (e.g., pregnancy and birth complications, acquired brain damage, toxins, infections, and genetic effects) can give rise to the disorder through some disturbance in a final common pathway in the nervous system.

51. Overview Continued
That final common pathway appears to be the integrity of the prefrontal cortical-striatal network.
It now appears that hereditary factors play the largest role in the occurrence of ADHD symptoms in children.
It may be that what is transmitted genetically is a tendency toward a smaller and less active prefrontal-striatal network.

52. Overview Continued
The condition can also be caused or exacerbated by pregnancy complications, exposure to toxins, or neurological disease
Social factors alone cannot be supported as causal in this disorder, but such factors may exacerbate the condition, contribute to its persistence, and more likely, contribute to the forms of comorbid disorders associated with ADHD.
Cases of ADHD can arise without genetic predisposition if the child is exposed to a significant disruption or neurological injury to this final common neurological pathway, but this would seem to account for only a small minority of ADHD children. “

53. Treatment of ADHD Stimulant Medications Other Medications
Psychosocial Treatments
Educational Accommodations

54. Commonly Used Stimulant Medications
Ritalin
Dexadrine
Adderall
Concerta
Between 70 and 80 % of children with ADHD respond positively to stimulant drugs.
Stimulant drugs represent an empirically supported treatment for core symptoms of ADHD.

55. Side Effects of Stimulants
Common side effects can include: loss of appetite, weight loss, sleeping problems, irritability,
restlessness, stomachache, headache, rapid heart rate, elevated blood pressure, sudden deterioration of behavior
symptoms of depression with sadness, crying, and withdrawn behavior.
intensification of tics (muscle twitches of the face and other parts of the body), possible Tourette’s and growth suppression.

56. Side Effects (Cont.)
While side effects are always a possibility they are often
Transient in nature
The result of inappropriate medication levels
If one medication results in side effects, another might be used without side effects.
Sometimes other medications are used to minimize side effects.
Good clinical judgment by the clinician may help to minimize side effects.

57. Some Examples of NonStimulant Drugs in ADHD Treatment
Non Stimulant ADHD Medication
Straterra - a norepinephrine reuptake inhibitor- selectively blocks the reuptake of norepinephrine, which increases its availability
Other Non Stimulant Drugs
Anti-depressants (e.g., Tofranil, Wellbutrin)
Anti-hypertensives (Clonidine)

58. Psychosocial Treatments
Parent Training
Social Skills Training
Cognitive Behavioral Treatments.
Psychotherapy for comorbid conditions

59. Educational Interventions
Special Education Services for existing learning problems.
Classroom accommodations.
Classroom behavior modification programs.

60. ADHD Treatment: Concluding Comments
In treating ADHD it is essential to treat the full range of difficulties that impact on child and family functioning.
Treatment of ADDH will often need to be “multimodal” in nature.
Findings from the Multimodal Treatment Study suggest that;
Stimulant medication is effective in reducing core symptoms
Psychosocial treatments are of value in addressing associated comorbidities.

61. That’s All Folks!