Attention Deficit Hyperactivity Attention Deficit Hyperactivity DisorderDisorder

James H. Johnson, Ph.D., ABPP/James H. Johnson, Ph.D., ABPP/ChildChild

University of FloridaUniversity of Florida

ADHD: Nature of the ProblemADHD: Nature of the Problem ADHD is a neurodevelopmental ADHD is a neurodevelopmental

disorder of childhood that is disorder of childhood that is characterized by characterized by developmentally inappropriate developmentally inappropriate levels of:levels of:

– Hyperactivity,Hyperactivity,– Impulsivity,Impulsivity,– Inattention.Inattention.

ADHD: How Common is it?ADHD: How Common is it? Prevalence is estimated at 3 to 9 per Prevalence is estimated at 3 to 9 per

cent of the elementary school cent of the elementary school population.population.

ADHD occurs more often in males than ADHD occurs more often in males than females, with the sex ratio being about females, with the sex ratio being about 4 to 1.4 to 1.

One of the most common disorders of One of the most common disorders of childhoodchildhood

Accounts for a large number of referrals Accounts for a large number of referrals to pediatricians, family physicians and to pediatricians, family physicians and child mental health professionals.child mental health professionals.

ADHD: Not a New ProblemADHD: Not a New Problem Characteristics of this disorder have Characteristics of this disorder have

been recognized for at least a century.been recognized for at least a century. Still (1902): ADHD Case studyStill (1902): ADHD Case study Fidgety Phil Fidgety Phil

((http://www.fln.vcu.edu/struwwel/philipp_e.htmlhttp://www.fln.vcu.edu/struwwel/philipp_e.html Has been referred to by a variety of Has been referred to by a variety of

labels;labels;

– Minimal Brain Dysfunction (MBD)Minimal Brain Dysfunction (MBD)– Hyperkinetic Reaction of ChildhoodHyperkinetic Reaction of Childhood– Attention Deficit Disorder (ADD)Attention Deficit Disorder (ADD)– Attention Deficit Hyperactivity Disorder Attention Deficit Hyperactivity Disorder

(ADHD)(ADHD)

Some Highlights in the Evolution of Some Highlights in the Evolution of the Disorderthe Disorder

Encephalitis epidemic of 1917 - 1918Encephalitis epidemic of 1917 - 1918 Frontal lobe ablation studies with Frontal lobe ablation studies with

primates (1930’s)primates (1930’s) Strauss’ work on Minimal Brain Strauss’ work on Minimal Brain

Dysfunction (1940's -1950's)Dysfunction (1940's -1950's) Beginnings of child Beginnings of child

psychopharmacology; Using psychopharmacology; Using Amphetamines for treatment – 1930-Amphetamines for treatment – 1930-1940.1940.

MBD becomes Hyperkinetic Disorder MBD becomes Hyperkinetic Disorder (the 1960’s)(the 1960’s)

Evolution of the Disorder (cont.)Evolution of the Disorder (cont.) The focus on attention – The 1970’sThe focus on attention – The 1970’s Focus on the Feingold dietFocus on the Feingold diet Studies of psychophysiological Studies of psychophysiological

responsivityresponsivity Development of objective diagnostic Development of objective diagnostic

criteria: DSM III- and ADD (the early criteria: DSM III- and ADD (the early 1980’s)1980’s)

The 1990’s - Present:The 1990’s - Present:– Imaging,Imaging,– Genetics,Genetics,– DSM IVDSM IV– Focus on Evidence Based Methods.Focus on Evidence Based Methods.

ADHD: Core FeaturesADHD: Core Features

As noted earlier, ADHD is a As noted earlier, ADHD is a disorder characterized by disorder characterized by developmentally developmentally inappropriate levels of :inappropriate levels of :

– Hyperactivity/ImpulsivityHyperactivity/Impulsivity– Inattention.Inattention.

DSM IV Symptoms of DSM IV Symptoms of Hyperactivity/ImpulsivityHyperactivity/Impulsivity

Fidgets with hands or feet, Fidgets with hands or feet, squirms in seat.squirms in seat.

Leaves seat in classroom or in Leaves seat in classroom or in other situations in which other situations in which remaining seated is expected remaining seated is expected

Runs about or climbs excessively Runs about or climbs excessively in situations in which it is in situations in which it is inappropriate. inappropriate.

More Symptoms of HyperactiveMore Symptoms of Hyperactive

Has difficulty playing or engaging Has difficulty playing or engaging in leisure activities quietly.in leisure activities quietly.

Often "on the go" or often acts as Often "on the go" or often acts as if "driven by a motor“.if "driven by a motor“.

Talks excessively when Talks excessively when inappropriate to the situationinappropriate to the situation

Symptoms of ImpulsivitySymptoms of Impulsivity

Blurts out answers before Blurts out answers before questions have been completed.questions have been completed.

Has difficulty awaiting turn.Has difficulty awaiting turn.

Interrupts or intrudes on others.Interrupts or intrudes on others.

Six symptoms of hyperactivity Six symptoms of hyperactivity and and impulsivity (combined) are required impulsivity (combined) are required for diagnosis. for diagnosis.

What do we Know about What do we Know about Hyperactivity?Hyperactivity?

Children with ADHD are more active, Children with ADHD are more active, restless, and fidgety than normal restless, and fidgety than normal children during the day children during the day andand during during sleep.sleep.

There are different types of There are different types of hyperactivity.hyperactivity.– Gross Motor ActivityGross Motor Activity– Restless/SquirmyRestless/Squirmy– Occasionally see verbal hyperactivityOccasionally see verbal hyperactivity

Hyperactivity often varies according Hyperactivity often varies according to situationto situation

Level of stimulationLevel of stimulation

Symptoms of InattentionSymptoms of Inattention Fails to give close attention to Fails to give close attention to

details details oror makes careless mistakes. makes careless mistakes. Has difficulties Has difficulties sustaining attentionsustaining attention

in tasks or play activities.in tasks or play activities. Does not seem to listen when Does not seem to listen when

spoken to directly.spoken to directly. Does not follow through on Does not follow through on

instructions and fails to finish instructions and fails to finish homework, chores, or duties in the homework, chores, or duties in the workplaceworkplace

More Symptoms of InattentionMore Symptoms of Inattention Has difficulty organizing tasks and Has difficulty organizing tasks and

activities activities Avoids, dislikes, or is reluctant to Avoids, dislikes, or is reluctant to

engage in tasks that require sustained engage in tasks that require sustained mental effort.mental effort.

Loses things necessary for tasks or Loses things necessary for tasks or activitiesactivities

Easily distracted by extraneous stimuli.Easily distracted by extraneous stimuli. Forgetful in daily activitiesForgetful in daily activities

(Six or more symptoms of inattention necessary for (Six or more symptoms of inattention necessary for diagnosis)diagnosis)

What Do We Know About ADHD What Do We Know About ADHD Attention Problems? Attention Problems?

ADHD "attention" problems may be most ADHD "attention" problems may be most obvious on specific types of tasks. obvious on specific types of tasks.

Children with ADHD have their greatest Children with ADHD have their greatest difficulties with difficulties with sustaining their sustaining their attentionattention in responding to tasks - in in responding to tasks - in being vigilant.being vigilant.

Problems are usually seen in situations Problems are usually seen in situations requiring the child to attend requiring the child to attend over timeover time to dull, boring, and repetitive tasks.to dull, boring, and repetitive tasks.

Situational Variations in SymptomsSituational Variations in Symptoms

Symptoms can show significant Symptoms can show significant variation across situations.variation across situations.

Children do not display Children do not display symptoms in all situationssymptoms in all situations

The absence of symptoms in The absence of symptoms in some situations (e.g. video some situations (e.g. video games) does not mean that the games) does not mean that the child does child does notnot have ADHD. have ADHD.

Situations That Situations That IncreaseIncrease ADHD SymptomsADHD Symptoms

The greater the demands of the situation, the The greater the demands of the situation, the more problematic the behavior will likely more problematic the behavior will likely become.become.

An An exceptionexception might be in situations where the might be in situations where the child is being continuously rewarded for child is being continuously rewarded for complying with demands.complying with demands.

In familiar situations where novelty and task In familiar situations where novelty and task stimulation are low.stimulation are low.

When FatiguedWhen Fatigued– Studies, monitoring 24 hour activity levels have Studies, monitoring 24 hour activity levels have

suggested that the hours of suggested that the hours of 1 – 51 – 5 seem to be peak seem to be peak times for increased activity in children with ADHD.times for increased activity in children with ADHD.

Overview of Diagnostic CriteriaOverview of Diagnostic Criteria Symptom CriteriaSymptom Criteria - Core Symptoms of - Core Symptoms of

Hyperactivity & Impulsivity and/or Inattention Hyperactivity & Impulsivity and/or Inattention (Six or More Symptoms of either category).(Six or More Symptoms of either category).

Duration CriterionDuration Criterion - Symptoms have Persisted for - Symptoms have Persisted for at Least 6 Months.at Least 6 Months.

Developmental CriterionDevelopmental Criterion - Symptoms are - Symptoms are Inconsistent with Developmental Level (MR).Inconsistent with Developmental Level (MR).

Impairment CriterionImpairment Criterion - Clear Evidence of - Clear Evidence of Clinically Significant Impairment in Social, Clinically Significant Impairment in Social, Academic, or Occupational FunctioningAcademic, or Occupational Functioning

Overview of Criteria (cont.)Overview of Criteria (cont.) Age CriterionAge Criterion - Some Symptoms that Cause - Some Symptoms that Cause

Impairment Were Present Before Age 7.Impairment Were Present Before Age 7. Situation CriterionSituation Criterion - Some Impairment from - Some Impairment from

Symptoms is Present in Two or More Settings.Symptoms is Present in Two or More Settings. NOTE.NOTE. The failure to attend to full range of The failure to attend to full range of

symptoms is not uncommonsymptoms is not uncommon Presence of hyperactivity, impulsivity, and Presence of hyperactivity, impulsivity, and

inattention is inattention is notnot necessarily to be equated with necessarily to be equated with ADHD.ADHD.

Types of ADHDTypes of ADHD

Combined TypeCombined Type– Symptoms of hyperactivity, impulsivity and Symptoms of hyperactivity, impulsivity and

inattention.inattention. Hyperactive/Impulsive Hyperactive/Impulsive (Does it really exist?)(Does it really exist?)

– Symptoms of hyperactivity and impulsivity.Symptoms of hyperactivity and impulsivity. Predominately InattentivePredominately Inattentive

– Symptoms of inattention. Symptoms of inattention.

ADHD MimicryADHD Mimicry Sensory ImpairmentsSensory Impairments Medication side effectsMedication side effects

– PhenobarbitalPhenobarbital– DilantinDilantin– Some Asthma MedicationsSome Asthma Medications

Seizure DisorderSeizure Disorder RTH (Resistance to Thyroid Hormone)RTH (Resistance to Thyroid Hormone) PTSDPTSD Bipolar DisorderBipolar Disorder Anxiety DisordersAnxiety Disorders Depressive DisordersDepressive Disorders

Comorbid ConditionsComorbid Conditions What are comorbid conditions?What are comorbid conditions? Controversy over use of the term.Controversy over use of the term. Why is it essential to consider the possibility of Why is it essential to consider the possibility of

comorbid conditions in assessing children with comorbid conditions in assessing children with ADHD?ADHD?

Importance of distinguishing between comorbid Importance of distinguishing between comorbid conditions and mimicry.conditions and mimicry.

What is the frequency of comorbidities in What is the frequency of comorbidities in children with ADHD?children with ADHD?

Comorbid ConditionsComorbid Conditions Learning Disabilities ~ 19 to 26%Learning Disabilities ~ 19 to 26% Oppositional Defiant Disorder ~ 40% Conduct Disorder Oppositional Defiant Disorder ~ 40% Conduct Disorder

~ 25% children; ~ 45-50% Adolescents.~ 25% children; ~ 45-50% Adolescents. Anxiety Disorders ~ 30% Anxiety Disorders ~ 30% Depressive Disorder ~ 10 - 30% Depressive Disorder ~ 10 - 30% Bipolar Disorder – up to 20%.Bipolar Disorder – up to 20%. Tics and Tourette’s Disorder ~ 7% of children with Tics and Tourette’s Disorder ~ 7% of children with

ADHD have a tic disorder.ADHD have a tic disorder. ~ 40 to 50% of those with Tourette’s disorder have ~ 40 to 50% of those with Tourette’s disorder have

ADHDADHD

Developmental IssuesDevelopmental Issues There are factors in infancy (e.g., difficult There are factors in infancy (e.g., difficult

temperament) that seem to be precursors of ADHD.temperament) that seem to be precursors of ADHD. Initial development of ADHD is most often during the Initial development of ADHD is most often during the

preschool years.preschool years. While there is often a decline in the level of While there is often a decline in the level of

hyperactivity and perhaps some improvement in hyperactivity and perhaps some improvement in attention and impulse control in adolescence, as many attention and impulse control in adolescence, as many as 70 % continue to be impaired by their symptoms as 70 % continue to be impaired by their symptoms and meet criteria for and meet criteria for some typesome type of ADHD. of ADHD.

A significant number of children with ADHD A significant number of children with ADHD (probably over 50%) continue to display problems (probably over 50%) continue to display problems into the adult years.into the adult years.

Prognosis of ADHDPrognosis of ADHD Outcome of ADHD in adolescents is highlighted by Outcome of ADHD in adolescents is highlighted by

the results of a study by the results of a study by Barkley, Fischer, et al, Barkley, Fischer, et al, (1990).(1990).

Study followed a large sample of children with Study followed a large sample of children with ADHD (158) and normal children (81) prospectively ADHD (158) and normal children (81) prospectively for 8 years after diagnosis.for 8 years after diagnosis.

123 hyperactive children123 hyperactive children and and 66 normals66 normals were were located, interviewed and complete questionnaires.located, interviewed and complete questionnaires.

In the hyperactive group 12 (9.7%) were female and In the hyperactive group 12 (9.7%) were female and 111 were male. In the normal group 4 of the subjects 111 were male. In the normal group 4 of the subjects were female and 62 were male.were female and 62 were male.

Prognosis In Adolescence Prognosis In Adolescence The majority of the hyperactive subjects The majority of the hyperactive subjects

(71.5%) met DSM III-R criteria for ADHD at (71.5%) met DSM III-R criteria for ADHD at follow up [follow up [Biederman (2000) found ~ 70%].Biederman (2000) found ~ 70%].– Note DSM III – R criteria changeNote DSM III – R criteria change

More than 59% met criteria for Oppositional More than 59% met criteria for Oppositional Defiant Disorder as compared to 11% of the Defiant Disorder as compared to 11% of the controls.controls.

  Approximately 43 % of the hyperactive group Approximately 43 % of the hyperactive group could be diagnosed as CD as compared to 1.6% could be diagnosed as CD as compared to 1.6% of the control group.of the control group.

What About Driving ?What About Driving ? Hyperactive subjects were Hyperactive subjects were more likely to have more likely to have

had an auto accidenthad an auto accident, to have had , to have had more more automobile accidentsautomobile accidents, to have had , to have had more bodily more bodily injuriesinjuries in accidents, and to be in accidents, and to be at fault for at fault for accidentsaccidents more often than did controls. more often than did controls.

Adolescents in the hyperactive group were also Adolescents in the hyperactive group were also more likely to have received traffic citationsmore likely to have received traffic citations , , especially for speeding especially for speeding

How About Substance Use ?How About Substance Use ? Cigarette and alcohol use were the only Cigarette and alcohol use were the only

categories of substance use that differentiated categories of substance use that differentiated those with hyperactivity from normals. those with hyperactivity from normals.

When the the hyperactive sample was separated When the the hyperactive sample was separated into groups (into groups (purely ADHD and ADHD + CDpurely ADHD and ADHD + CD) ) purely ADHD subjects showed no greater use of purely ADHD subjects showed no greater use of cigarettes, alcohol, or marijuana than did normal cigarettes, alcohol, or marijuana than did normal controls.controls.

Mixed hyperactive/Conduct disordered children Mixed hyperactive/Conduct disordered children displayed displayed two to five timestwo to five times the rate of substance the rate of substance use as did pure hyperactives or normals.use as did pure hyperactives or normals.

What About School Performance?What About School Performance? Three times as many hyperactives had failed a grade Three times as many hyperactives had failed a grade

(29.3% versus 10%), had been suspended (46.3% (29.3% versus 10%), had been suspended (46.3% versus 15.2%) or had been expelled (10.6% versus versus 15.2%) or had been expelled (10.6% versus 1.5%). 1.5%).

Results indicated that hyperactivity alone increases the Results indicated that hyperactivity alone increases the risk of suspension (30.6% vs 15.2%), and dropping out risk of suspension (30.6% vs 15.2%), and dropping out

(4.8% vs 0% ) as compared to controls(4.8% vs 0% ) as compared to controls However, the added diagnosis of CD greatly increases However, the added diagnosis of CD greatly increases

the risk (67% suspended, 13% dropped out). the risk (67% suspended, 13% dropped out). The presence of CD accounted almost entirely for the > The presence of CD accounted almost entirely for the >

risk of expulsion within the hyperactive group risk of expulsion within the hyperactive group

Prognosis In AdulthoodPrognosis In Adulthood Studies have suggested that anywhere Studies have suggested that anywhere between 4 and 60 % of between 4 and 60 % of

children diagnosed with ADHD will display symptoms in children diagnosed with ADHD will display symptoms in adulthoodadulthood serious enough to interfere with academic, vocational serious enough to interfere with academic, vocational or social functioning.or social functioning.

Variability in results likely relates to different criteria used for Variability in results likely relates to different criteria used for diagnosis of ADHD in adults.diagnosis of ADHD in adults.

There are indications that the type of ADHD that persists into There are indications that the type of ADHD that persists into adulthood is adulthood is more highly geneticmore highly genetic than the type that remits in than the type that remits in childhood.childhood.

ADHD in adults is sometimes considered a ADHD in adults is sometimes considered a “hidden disorder”“hidden disorder” as symptoms are often obscured by other problems.as symptoms are often obscured by other problems.

Prevalence is thought to be 2 – 4% with sex ratio of 2 – 1 Prevalence is thought to be 2 – 4% with sex ratio of 2 – 1 or or lowerlower).).

Etiology:ADHD Risk FactorsEtiology:ADHD Risk Factors Maternal cigarette useMaternal cigarette use Maternal alcohol useMaternal alcohol use Maternal drug useMaternal drug use A variety of factors that can be A variety of factors that can be

related to fetal distressrelated to fetal distress– Unusually long or short laborUnusually long or short labor– Forceps deliveryForceps delivery– ToxemiaToxemia– Meconium stainingMeconium staining– Nuchal cordNuchal cord

Birth during the month of September.Birth during the month of September. Minor physical anomaliesMinor physical anomalies

Etiology - GeneticsEtiology - Genetics Between 10 and 35 per-cent of the Between 10 and 35 per-cent of the

immediate family members of children immediate family members of children with ADHD also display this disorder.with ADHD also display this disorder.

Risk for siblings of children with ADHD Risk for siblings of children with ADHD is approximately 32% is approximately 32%

If a parent has ADHD the risk to If a parent has ADHD the risk to offspring is on the order of 50+%offspring is on the order of 50+%

Twin studies suggest concordance Twin studies suggest concordance rates for monozygotic twins is around rates for monozygotic twins is around 80% with concordance rates of 30% 80% with concordance rates of 30% for dz twins.for dz twins.

Etiology - GeneticsEtiology - Genetics Overall, twin studies suggest an average Overall, twin studies suggest an average

heritability of .80heritability of .80 Work in the area of molecular genetics has Work in the area of molecular genetics has

also identified specific genes related to also identified specific genes related to ADHD.ADHD.

Molecular genetics has begun to identify Molecular genetics has begun to identify specific genes related to ADHDspecific genes related to ADHD

These genes have to do with the These genes have to do with the transporttransport of and of and post-synaptic sensitivitypost-synaptic sensitivity to the to the neurotransmitter dopamine in the frontal neurotransmitter dopamine in the frontal lobes.lobes.

Hereditary is one of the most well Hereditary is one of the most well supported etiological factors in the supported etiological factors in the development of ADHDdevelopment of ADHD

Etiology – Neurological InsultEtiology – Neurological Insult Multiple factors that can result in brain Multiple factors that can result in brain

damage are associated with ADHD.damage are associated with ADHD. For example, For example, anoxiaanoxia, is associated with , is associated with

increased frequencies of hyperactivity increased frequencies of hyperactivity and attention problems.and attention problems.

ADHD occurs more often in children with ADHD occurs more often in children with seizure disordersseizure disorders, who are presumed to , who are presumed to have neurological involvementhave neurological involvement

As noted earlier, As noted earlier, diseases like diseases like encephalitisencephalitis can also result in symptoms can also result in symptoms of ADHD, as can various types of of ADHD, as can various types of infections.infections.

Etiology: Brain DamageEtiology: Brain Damage These findings suggest that neurological These findings suggest that neurological

insult insult cancan result in an increased probability result in an increased probability of developing ADHD.of developing ADHD.

However, However, most children with ADHD do not most children with ADHD do not have a significant history of brain injuryhave a significant history of brain injury..

Such injuries are unlikely to account for Such injuries are unlikely to account for ADHD in most children. ADHD in most children.

In fact In fact probably 95% of hyperactive children probably 95% of hyperactive children show show nono evidence of documentable evidence of documentable neurological impairmentneurological impairment. .

This does not mean, however, that This does not mean, however, that neurodevelopmental factors are not neurodevelopmental factors are not involved. involved.

Neuropsychological Test Findings:Neuropsychological Test Findings:Executive functioning deficitsExecutive functioning deficits

Results from research involving Results from research involving neuropsychological testing has often neuropsychological testing has often suggested that children with ADHD have suggested that children with ADHD have problems;problems;– in inhibiting behavioral responses,in inhibiting behavioral responses,– in initiating behaviorin initiating behavior– in shifting from one activity to anotherin shifting from one activity to another– with working memory,with working memory,– with planning and organization, with planning and organization, – with perseveration,with perseveration,– in motor sequencing,in motor sequencing,– with other frontal lobe functions.with other frontal lobe functions.

Executive Functioning DeficitsExecutive Functioning Deficits Not only do children with ADHD show Not only do children with ADHD show

executive functioning deficits but executive functioning deficits but siblings of ADHD children siblings of ADHD children who do not who do not have ADHDhave ADHD, have been shown to , have been shown to display milder yet significant display milder yet significant impairments of the same typeimpairments of the same type..

This suggests a possible This suggests a possible genetic risk genetic risk for executive function deficitsfor executive function deficits in in families.families.

Studies of Brain FunctionStudies of Brain Function Studies of cerebral blood flow in Studies of cerebral blood flow in

ADHD and normal children have ADHD and normal children have consistently shown consistently shown decreased blood decreased blood flow to the prefrontal regions and flow to the prefrontal regions and pathways connecting these regions pathways connecting these regions to the limbic system via the striatum to the limbic system via the striatum

Studies using PET scans to assess Studies using PET scans to assess cerebral glucose metabolism in the cerebral glucose metabolism in the frontal regions have found frontal regions have found diminished metabolismdiminished metabolism in, adults and in, adults and adolescent females with ADHD.adolescent females with ADHD.

Cerebral Blood Flow (cont)Cerebral Blood Flow (cont) A significant correlation between A significant correlation between

diminished metabolic activity in the diminished metabolic activity in the left anterior frontal regionleft anterior frontal region and and severity of symptomsseverity of symptoms in adolescents in adolescents with ADHD has also been with ADHD has also been demonstrated. demonstrated.

This demonstration of a relationship This demonstration of a relationship between decreased metabolic activity between decreased metabolic activity and the symptom and the symptom severityseverity is crucial to is crucial to documenting the importance of the documenting the importance of the link between lower levels of brain link between lower levels of brain activation and ADHD-related behavior.activation and ADHD-related behavior.

Frontal LobesFrontal Lobes

Basal GangliaBasal Ganglia

MRI StudiesMRI Studies Some, but not all studies have found Some, but not all studies have found

differences in the differences in the Corpus Callosum,Corpus Callosum, with this structure being smaller in with this structure being smaller in children with ADHD.children with ADHD.

Other MRI studies have found children Other MRI studies have found children with ADHD to have a with ADHD to have a smaller left smaller left caudate nucleuscaudate nucleus than normal children. than normal children.

These findings are interesting in light These findings are interesting in light of the results of earlier blood flow of the results of earlier blood flow studies suggesting lower levels of studies suggesting lower levels of activation in this area in children with activation in this area in children with ADHD.ADHD.

MRI ContinuedMRI Continued Several more recent MRI studies, with Several more recent MRI studies, with

larger samples, have suggested that larger samples, have suggested that children with ADHD had significantly children with ADHD had significantly smaller anterior smaller anterior right frontal regionsright frontal regions, , a smaller caudate nucleus, and a smaller caudate nucleus, and smaller globus pallidus regions than smaller globus pallidus regions than normals.normals.

Research has also found Research has also found decreased decreased cerebellar volumecerebellar volume in children with in children with ADHD.ADHD.

Work in this area suggests that Work in this area suggests that abnormalities in the development of abnormalities in the development of the frontal-striatal regions may well the frontal-striatal regions may well underlie the development of ADHD.underlie the development of ADHD.

Neurotransmitter DeficienciesNeurotransmitter Deficiencies The possibility of a neurotransmitter The possibility of a neurotransmitter

dysfunction in children with ADHD has dysfunction in children with ADHD has been suggested for many years.been suggested for many years.

This notion seemed to originate from This notion seemed to originate from the fact that children with ADHD the fact that children with ADHD respond to different types of stimulant respond to different types of stimulant drugs.drugs.

The fact that stimulant drugs have an The fact that stimulant drugs have an impact on ADHD and that they impact on ADHD and that they increaseincrease dopamine has contributed to the dopamine has contributed to the neurotransmitter dysfunction neurotransmitter dysfunction hypothesis.hypothesis.

Neurotransmitter DeficienciesNeurotransmitter Deficiencies There is more direct evidence of There is more direct evidence of

neurotransmitter deficiencies from neurotransmitter deficiencies from some studies of cerebral spinal fluid in some studies of cerebral spinal fluid in children with and without ADHD, which children with and without ADHD, which suggests suggests decreased dopamine levelsdecreased dopamine levels in in childrenchildren with ADHDwith ADHD

There is also some evidence of a There is also some evidence of a deficiency in the availability of deficiency in the availability of norepinephrinenorepinephrine in children with ADHD. in children with ADHD.

This is of interest given that a This is of interest given that a relatively new non-stimulant ADHD relatively new non-stimulant ADHD medication, Straterra, is thought to act medication, Straterra, is thought to act on norepinephrine levels.on norepinephrine levels.

Etiology: Psychosocial FactorsEtiology: Psychosocial Factors There is little evidence for the role There is little evidence for the role

of psychosocial factors in the of psychosocial factors in the developmentdevelopment of ADHD, although of ADHD, although factors such as parent-child conflict factors such as parent-child conflict may exacerbate problems in a child may exacerbate problems in a child with ADHD.with ADHD.

Psychosocial factors may also Psychosocial factors may also contribute to the development of contribute to the development of certain comorbid disorders that certain comorbid disorders that may complicate the clinical picture.may complicate the clinical picture.

Etiology: OverviewEtiology: Overview In reviewing the literature on the In reviewing the literature on the

etiology of ADHD, Barkley suggests …etiology of ADHD, Barkley suggests …– ““It should be evident from the research…It should be evident from the research…

that neurological and genetic factors make that neurological and genetic factors make a substantial contribution to symptoms of a substantial contribution to symptoms of ADHD and the occurrence of this disorder.ADHD and the occurrence of this disorder.

– A variety of genetic and neurological A variety of genetic and neurological etiologies (e.g., pregnancy and birth etiologies (e.g., pregnancy and birth complications, acquired brain damage, complications, acquired brain damage, toxins, infections, and genetic effects) can toxins, infections, and genetic effects) can give rise to the disorder through some give rise to the disorder through some disturbance in a disturbance in a finalfinal common pathwaycommon pathway in in the nervous system.the nervous system.

Overview ContinuedOverview Continued That final common pathway appears to be the That final common pathway appears to be the

integrity of the prefrontal cortical-striatal integrity of the prefrontal cortical-striatal network.network.

It now appears that hereditary factors play the It now appears that hereditary factors play the largest role in the occurrence of ADHD largest role in the occurrence of ADHD symptoms in children. symptoms in children.

It may be that what is transmitted genetically is It may be that what is transmitted genetically is a tendency toward a smaller and less active a tendency toward a smaller and less active prefrontal-striatal network. prefrontal-striatal network.

Overview ContinuedOverview Continued The condition can also be caused or The condition can also be caused or

exacerbated by pregnancy exacerbated by pregnancy complications, exposure to toxins, complications, exposure to toxins, or neurological disease or neurological disease

Cases of ADHD can arise without Cases of ADHD can arise without genetic predisposition if the child is genetic predisposition if the child is exposed to a significant disruption exposed to a significant disruption or neurological injury to this final or neurological injury to this final common neurological pathway.common neurological pathway.

This would seem to account for only This would seem to account for only a small minority of ADHD children. “a small minority of ADHD children. “

Treatment of ADHD Treatment of ADHD

Stimulant MedicationsStimulant Medications Other MedicationsOther Medications Psychosocial TreatmentsPsychosocial Treatments Educational AccommodationsEducational Accommodations

Commonly Used Stimulant Commonly Used Stimulant MedicationsMedications

RitalinRitalin DexadrineDexadrine AdderallAdderall ConcertaConcertaBetween 70 and 80 % of children with ADHD respond Between 70 and 80 % of children with ADHD respond

positively to stimulant drugs.positively to stimulant drugs.Stimulant drugs represent an empirically supported Stimulant drugs represent an empirically supported

treatment for treatment for core symptomscore symptoms of ADHD. of ADHD.

Side Effects of StimulantsSide Effects of Stimulants Common side effects can include: loss of Common side effects can include: loss of

appetite, weight loss, sleeping problems, appetite, weight loss, sleeping problems, irritability,irritability,

restlessness, stomachache, headache, rapid restlessness, stomachache, headache, rapid heart rate, elevated blood pressure, sudden heart rate, elevated blood pressure, sudden deterioration of behaviordeterioration of behavior

symptoms of depression with sadness, symptoms of depression with sadness, crying, and withdrawn behavior.crying, and withdrawn behavior.

intensification of tics (muscle twitches of intensification of tics (muscle twitches of the face and other parts of the body), the face and other parts of the body), possible Tourette’s and growth suppression. possible Tourette’s and growth suppression.

Side Effects (Cont.)Side Effects (Cont.) While side effects are always a possibility While side effects are always a possibility

they are oftenthey are often– Transient in natureTransient in nature– The result of inappropriate medication levelsThe result of inappropriate medication levels

If one medication results in side effects, If one medication results in side effects, another might be used without side effects.another might be used without side effects.

Sometimes other medications are used to Sometimes other medications are used to minimize side effects.minimize side effects.

Good clinical judgment by the clinician may Good clinical judgment by the clinician may help to minimize side effects.help to minimize side effects.

Some Examples of NonStimulant Drugs Some Examples of NonStimulant Drugs in ADHD Treatmentin ADHD Treatment

Non Stimulant ADHD MedicationNon Stimulant ADHD Medication– Straterra - Straterra - a norepinephrine reuptake inhibitor- selectively a norepinephrine reuptake inhibitor- selectively

blocks the reuptake of norepinephrine, which increases its blocks the reuptake of norepinephrine, which increases its availabilityavailability

Other Non Stimulant DrugsOther Non Stimulant Drugs– Anti-depressants (e.g., Tofranil, Wellbutrin)Anti-depressants (e.g., Tofranil, Wellbutrin)– Anti-hypertensives (Clonidine)Anti-hypertensives (Clonidine)

Psychosocial TreatmentsPsychosocial Treatments

Parent TrainingParent Training Social Skills TrainingSocial Skills Training Cognitive Behavioral Treatments.Cognitive Behavioral Treatments. Psychotherapy for comorbid conditionsPsychotherapy for comorbid conditions

Educational InterventionsEducational Interventions Special Education Services for existing Special Education Services for existing

learning problems.learning problems. Classroom accommodations.Classroom accommodations. Classroom behavior modification programs.Classroom behavior modification programs.

Treatment: Concluding CommentsTreatment: Concluding Comments In treating ADHD it is essential to In treating ADHD it is essential to treat the treat the

full range of difficultiesfull range of difficulties that impact on child that impact on child and family functioning.and family functioning.

Treatment of ADDH will often need to be Treatment of ADDH will often need to be “multimodal” in nature.“multimodal” in nature.

Findings from the Multimodal Treatment Findings from the Multimodal Treatment Study suggest that;Study suggest that;– Stimulant medication is effective in reducing core Stimulant medication is effective in reducing core

symptomssymptoms– Psychosocial treatments are of value in Psychosocial treatments are of value in

addressing associated comorbidities.addressing associated comorbidities.

That’s All Folks!That’s All Folks!