Download ADHD and PDD

ADHD and PDD
The Overlap Between Attention-Deficit Hyperactivity Disorder and
Pervasive Developmental Disorders
Eileen Matias Davis, B.A.
ADHD & PDD
Outline


ADHD, PDD, and the DSM-IV-TR
Evidence for comorbidity




Theory of Mind and Executive Functioning
Psychostimulants in Tx of PDD



ADHD Sx in PDD
PDD Sx in ADHD
And other treatment implications
Different potential models for the relationship between
ADHD and PDD
Dual diagnosis
ADHD and PDD

ADHD is a neuropsychological disorder characterized by
developmentally inappropriate levels of hyperactivity,
impulsivity, and inattention.




Combined Type
Predominately Inattentive Type
Predominately Hyperactive Type
PDD is characterized by delays and deficits in the development
of social interaction, communication skills, and cognitive
abilities.





Autism
Asperger Syndrome
PDDNOS
Childhood Disintegrative Disorder
Rett Syndrome
Onset

ADHD
Sx must be present
before the age of 7



Although this is a somewhat
arbitrary number, we do know
that ADHD Sx must begin at
least in childhood
Concerns often begin
when the child starts preKindergarten
Initial diagnosis often
occurs in preschool years

PDD
Sx should be present in
the first years of life



Late onset: after 3 years
Parents usually start
expressing concern at 1218 months
Diagnosis often does not
occur until the child is 3
or 4
DSM-IV-TR
ADHD
6+
Sx of inattention (i.e. careless
mistakes, difficulty sustaining attn,
difficulty organizing tasks, etc.)
OR
6+ Sx of hyperactivity/impulsivity
(fidgets with hands or feet, acts as if
driven by motor, talks excessively
difficulty awaiting turn, etc.)
Impairment in 2+ settings
Impairment in social, academic, or
occupational functioning
Asperger’s
Qualitative
impairment in social
interaction (2+) (failure to develop peer
relationships appropriate to
developmental level, lack of
social/emotional reciprocity, etc)
Restricted repetitive and stereotyped
patterns of behavior, interests, and
activities (1+) (apparently inflexible
adherence to specific, nonfunctional
routines or rituals; stereotyped and
repetitive motor mannerisms, etc,)
Impairment in social, occupational, or
other areas of functioning
No significant delay in language
DSM-IV-TR
Autism
Qualitative
impairment in social interaction
(impaired use of non-verbal behaviors, lack of
social/emotional reciprocity, etc.)
Qualitative impairment in communication (delay
in/lack of development of spoken language, lack
of make-believe play, etc.)
Restricted repetitive and stereotyped patterns of
behavior, interests, activities (persistent
preoccupation with parts of objects,
encompassing preoccupation with stereotyped
patterns of interest, etc.)
Delays or abnormal functioning in social
interaction, language as used in social
communication, or symbolic/imaginative play
Sx present by age 3
PDDNOS
Severe
and pervasive impairment
in the development of reciprocal
social interaction
 Impairment in either verbal or
nonverbal communication skills or
presence of stereotyped behavior,
interests, and activities
criteria not met for specific PDD
Includes "atypical autism"
(presentations that do not meet the
criteria for Autistic Disorder
because of late age at onset),
atypical symptomatology, or subthreshold symptomatology
High-Functioning PDD



IQ ≥ 70
Mostly associated with PDD-NOS and
Asperger’s
Approximately 92% of kids with PDD-NOS are
high-functioning (Chakrabarti & Fombonne, 2001)
PDD-NOS



No positive criteria
Milder conditions that do not fit into the other PDD
categories are often given this label
No clear cutoffs for distinguishing kids with PDDNOS from normal kids or kids with other
psychopathology



This can make the distinction between PDD-NOS and ADHD
particularly difficult because the social interaction difficulties that
often occur in ADHD can be interpreted as PDD symptoms
A child with ADHD that also shows some PDD Sx may be given the
PDD-NOS Dx instead
Conversely, may kids with PDD-NOS are first given an ADHD Dx
Exclusionary Criteria




ADHD cannot be diagnosed in children if it occurs
exclusively within the course of PDD (Criterion E).
Because PDDs are chronic and unremitting conditions
that begin very early in life, there is virtually no period
where the ADHD symptoms could manifest alone in
most kids with PDD.
There is much debate about whether ADHD should be
diagnosable in children with PDD.
According to many clinicians, there is a significant
subset of kids who the DSM-IV can’t appropriately
diagnose as it stands.
Evidence for
Comorbidity
ADHD Sx in PDD

Frazier et al. (2001)


Structured Diagnostic Interviews of all kids referred to
psychopharmacology clinic due to behavior problems
83% of 60 PDD kids also met criteria for ADHD



PDD kids had similar PDD Sx regardless of ADHD comorbidity
ADHD kids had similar ADHD Sx regardless of PDD comorbidity
These findings suggest that the two disorders are
independent and provides support for comorbidity
Disclaimer: Using DSM-III-R
ADHD Sx in PDD

Goldstein & Schweback (2004)

Retrospective chart review of kids with PDD

16 (59%) met DSM-IV criteria for ADHD



7 (26%) combined type
9 (33%) inattentive type
PDD + ADHD did not show significantly greater
impairment (small sample size?)
ADHD Sx in PDD

Lee & Ousley (2006)

Systematic chart review of children and adolescents
with ASD

65 (78%) – met DSM-IV criteria for ADHD



64% combined type
14% inattentive type
5% hyperactive type
ADHD in Kids with PDDs
Yoshida & Uchiyama (2004)
67.9%
22.1%
Within PDD-group comorbidity:
Autistic Disorder – 58%
Asperger’s – 67%
PDDNOS – 88%
*All subjects were outpatients at the Yokohama Psycho-Developmental Clinic in Japan
Summary of ADHD Sx in PDD



Many kids with pervasive developmental
disorders meet criteria for ADHD
These symptoms appear to be independent of
PDD core features
It remains unclear whether PDD + ADHD is
associated with greater impairment than PDD
alone
Comorbidity: A Case Study
“Ichiro”
Ichiro is a 10-year-old male. His motor development was normal: He first walked at
the age of 10 months. However, his first words came at 18 months. Delayed verbal
skills, impairment in social interactions, and hyperactivity at 18-months suggested
autism. At 2 years, he began making two-word phrases. When he entered
kindergarten at age 4, hyperactivity decreased gradually, and he could participate in
group activities. By that time, he appeared to be just an active boy with no
developmental problems, and consultations stopped. Hyperactivity recurred when
he moved and changed kindergartens. His mother visited an educational
consultation center to request a behavioral evaluation when he was 5 yrs old. No
developmental delays were noted. Ichiro was markedly hyperactive from the first day
of elementary school. He could not remain seated and spoke without permission
during class. He also had difficulties with peer interactions, although he enjoyed
conversations with adults, including teachers.
Ichiro was diagnosed with ADHD by a psychiatrist when he was 6 years old.
Methylphenidate therapy (10 mg/day) began at 6 years and 2 months, and his
behavior improved remarkably. During class, he could remain seated and raise his
hand before speaking. He seldom had trouble with other children, but he could not
make friends. Six months later the medication was discontinued, and behavioral
problems recurred. Restarting methylphenidate relieved the problems rapidly.
Comorbidity: A Case Study
“Ichiro”
At that time, Ichiro’s sister was diagnosed with Asperger’s syndrome. This led
Ichiro’s mother to notice that his behavior seemed to match the Asperger’s profile as well.
Ichiro was re-evaluated at age 7. During his visit, the doctor played a game with him, the
object of which was to find a hidden coin in each other’s palms. The boy concealed the
coin in one hand by making a fist, but kept the other hand open. When the doctor
explained: “If you leave one hand open, I can guess where the coin is,” Ichiro took the
words literally, at face value. Ichiro opened both hands.
During the interview, Ichiro repeated the expression, “Oh, really?” unnaturally
often, and his intonation was too strong, so his speech sounded teasing.
His mother complained of difficulties in interacting with him. For instance, when
she said angrily that she would leave home because he never straightened his room, he
would respond: “Oh, really? Please tell me where the restaurant is.” The boy had no
friends at school, but did not seem to care unless he was bullied. He played alone at
home by acting out all parts of a role play, had much interest in atoms and molecules,
brushed his teeth for exactly 3 minutes, and had a habit of swinging a string. These
stereotyped bx/interests were not observed at school.
Comorbidity: A Case Study
“Ichiro”
The teachers thought that his poor social skills were secondary effects of ADHD.
His teacher was primarily concerned about Ichiro’s hyperactivity, impulsivity, and
inattention. Ichiro was always squirming in his seat. He was often blamed for leaving the
line at morning assembly. He frequently left or lost things at school. His teacher
described in a report card that the boy interrupted his classmates whenever an idea
occurred to him, and that he often forgot to do assigned tasks.
He showed poor gross and fine motor skills. Results of WISC-III showed a fullscale IQ of 120. At present, Ichiro continues taking methylphenidate (40mg/day). He
has no apparent troubles with peers, although he does not initiate play. The medication
has been effective for inattention as well as for hyperactivity. His careless mistakes on
tests have decreased, and he loses fewer things at school. He is an academically high
achiever.
Although Ichiro’s Sx indicate a diagnosis of Asperger’s, he was instead diagnosed
with PDDNOS because he also met diagnostic criteria for ADHD.
Discussion:
What are some of the
important/interesting issues and
concerns that you identified in this
case study?
Case Study
“Jiro”









No spoken language until 25 months
Vocabulary rapidly increased starting at 3 years
Poor eye contact, hyperactivity, restricted interest in letters early on
In school, could interact with peers as he skillfully drew pictures of pipes and
parking lots
Poor conversational skills and seldom spoke at school
Looked vacant and often forgot things
Restricted interest in fighter aircraft
Rapid increase in verbal production at age
9 or 10, but qualitative impairments in
social interaction and communication became
obvious again
He was willing to obey classmate’s directions in
order to gain acceptance
Case Study
“Jiro”

Diagnosed with Asperger’s syndrome at age 10.


At the next interview, he presented his doctor with a note asking
four questions:





He was told that his parents and doctors wanted to help him find ways to
better enjoy life
“I easily forget what’s been said to me. Why?”
“I cannot remember mathematical formulae. Why?”
“I cannot remember [Japanese characters]. Why?”
“I know many words, but cannot talk freely to people. Why?”
As he explained the letter, he began to cry. Jiro appeared more
distressed by his symptoms of inattention than my impairments
due to PDD, although the PDD would have a greater influence
on his later life.
Discussion:
What are some of the
important/interesting issues and
concerns that you identified in this
case study?
PDD Sx in ADHD

Social Dysfunctioning



Impairments in social interactions with peers
Inability to conceive other people’s feelings and thoughts (empathy)
Communication Impairments

Difficulties with certain aspects of pragmatic language





Inappropriate initiation of conversation
Inappropriate use of syntax
Odd forms of speech
Problems with nonverbal communication
Restricted Patterns of Bx, Interests, Activities

Stereotyped hand and body movements
Nijmeijer et al. 2008
PDD Sx in ADHD
Parent Report - Autism Criteria Checklist
Clark et al, 1999
Social Dysfunctioning

Deficits that appear directly related to ADHD core Sx:





Blurting out answers
Interrupting or intruding on conversations of others
Failing to attend to important social cues
Handling frustration in impulsive/aggressive manner
Deficits that may be due to other problems in social skills and
social information-processing:




Failure to comprehend the impact of one’s actions on others
Misinterpreting social information
Possessing a limited repertoire of social responses
Difficulty monitoring and responding to the ongoing stream of one’s
social interactions
(Greene et al., 1996)
Social Dysfunctioning

Green et al, 1996

22% of a sample of ADHD (vs. 0% of non-ADHD controls)
were classified as “socially disabled”


ADHD + Socially disabled



Used standardized discrepancy score between expected scores (based
on IQ) and observed scores on a measure of social functioning
greater impairment than non socially disabled ADHD kids on
measures of social functioning and patterns of psychiatric comorbidity
Suggests subset of ADHD kids with severe social dysfunction
Does this represent a sub-type of ADHD that is more closely
linked to PDD? Or perhaps comorbid ADHD/PDD?

More research is needed in this area
PDD Sx in Hyperkinetic Disorder
P.J. Santosh, et al. (2004)


Hyperkinetic Disorder is an ICD-10 diagnosis
that is ultimately a subset of ADHD combined
type (inattentiveness, hyperactivity, and
impulsivity all present in the same child).
Identified two social impairment subtypes:
Relationship Difficulties
 Social Communication
Difficulties

P.J. Santosh, et al.


Relationship Difficulties showed strong association only with conduct
problems and affective symptoms, as well as much greater association with
environmental stressors.
Social Communication Difficulties were associated with repetitive behaviors,
speech and language difficulties, developmental difficulties (all PDD Sx), as
well as affective symptoms, ADHD, and conduct problems.
PDD Sx in Hyperkinetic Disorder

HKD vs. psychiatric controls:
40% (vs. 18%) had difficulties in social reciprocity
 24% (vs. 17%) had speech and language difficulties
 9% (vs. 5%) repetitive behaviors and overcircumscribed
interests



Significantly more HKD kids had the PDD triad
‘Difficulties in social reciprocity’ was the most
common PDD domain and showed the highest
discrepancy between HKD and psychiatric
controls
Summary of PDD Sx in ADHD




Many children with ADHD show symptoms of PDD, particularly
difficulties in social reciprocity
Not all social deficits in kids with ADHD can be accounted for
by core features of the disorder
A subset of kids with ADHD (perhaps a more severe variant)
who are “socially disabled” may warrant a comorbid PDD
diagnosis
The social difficulties in these kids may be differentiated from
social difficulties commonly found in ADHD that are more
closely associated with conduct problems


Social Communication Difficulties (PDD) vs.
Difficulties (ODD/CD)
Relationship
It remains unclear whether the social difficulties in ADHD are only
similar in presentation to PDD or if they also share similar pathology
More ADHD/PDD Overlap
Evidence from Theory of Mind and
Executive Functioning
Theory of Mind


Results from ToM and emotion recognition tasks
tend to confirm the findings of a lack of awareness
of the feelings of others in children with ADHD
ToM


“The ability to attribute mental states, such as beliefs,
desires, and intentions to oneself and to other people
and thereby to understand and predict behavior.”
Most children with ADHD were found to be as
impaired on these tasks as children with highfunctioning autism and PDDNOS and more
impaired than both normal and clinical controls.
Especially with regard to second order mentalizing skills (the
ability to predict beliefs about beliefs)

Buitelaar et al. (1999)
Executive Functioning


EF Deficits (deficits in mental control processes) are
considered central deficits in both ADHD and PDD.
Some studies have shown that inhibition deficits may be
specific to ADHD and that children with PDD more often
show problems with planning and flexibility


However, these findings have not been consistently replicated and
may seem inconsistent with what we know about these disorders
Jonsdottir et al. (2006)

EF deficits in kids with ADHD were not related to ADHD
symptoms but instead to comorbid depressive and autistic
symptoms.
Treatment
Psychostimulants in PDD
Handen, Johnson, & Lubetsky, 2000



Double-blind, placebo-controlled study of 13 children
with autism and symptoms of ADHD
Given placebo, .3mg/kg MPH, and .6mg/kg MPH in
random order for seven days each
Measures:


Conners Teacher Scale, IOWA Conners Teacher Rating Scale, Aberrant
Behavior Checklist, Child Autism Rating Scale, Side Effects Checklist
61.5% were MPH responders



50%+ decrease on Teacher Conners Hyperactivity Index
Decreased inattention, hyperactivity, and aggression
Gains in “odd, bizarre behavior” and “repetitive speech”
Psychostimulants in
PDD
A number of adverse
side effects reported by
teachers
 Many of these side
effects were reported at
high rates during placebo
trial
 Most remained stable
across drug conditions

Handen, Johnson, & Lubetsky, 2000
Psychostimulants in PDD, cont.

Quintana et al. (1995)




10 kids received either 10mg MPH or placebo, followed by 2
weeks of 20mg MPH
Significant improvements on Conners and Aberant Behavior
Checklist
Side effects did not differ between drug and placebo conditions
Stigler et al. (2004)




Retrospective chart review of 195 children with PDDs
<25% responded to first stimulant trial
>50% experienced significant adverse effects
Pts with Asperger’s were significantly more likely to respond to
stimulant trial
Psychostimulants for Tx of PDD:
Summary





There is some evidence that stimulant meds can be beneficial
for some kids with PDD+ADHD
Reports of side effects are cause for concern
Need for more research looking at treatment response and side
effects within homogenous groups of children with PDD +
ADHD as compared to children with ADHD only
Perhaps psychostimulants can be an efficacious treatment for
ADHD Sx occuring in some PDD diagnoses (i.e. PDDNOS or
Asperger’s) more than others
No research on other treatments for ADHD Sx in PDD

http://psychcentral.com/news/2008/06/27/adhd-with-autism-explored/2516.html
Treating
ADHD + “Social Disability”



If the social impairments in a subset of kids with ADHD
resemble those in kids with PDDs in their severity, perhaps
some of the same PDD Tx approaches can be applied to
treating these deficits in the ADHD population.
These children may require Tx that differ in “form,
frequency, and intensity” from other ADHD kids and
perhaps more closely resemble Tx approaches for PDDs
What are some of the different treatment approaches that may be
used for this subset of kids (perhaps borrowed from PDD
literature)?
Modeling the
ADHD/PDD
Relationship
ADHD/PDD Continuum

Some researchers have suggested that ADHD falls on
the milder end of the PDD spectrum

An alternative possibility is that ADHD and PDD
represent two separate spectrums with overlapping Sx.
ADHD/PDD Continuum

A third alternative may be that the presence of severe
social impairments in kids with ADHD, or extreme
inattention and/or hyperactivity/impulsivity in kids
with PDD actually represents the co-occurrence of the
two disorders.
Benefits of Dual Diagnosis






Explains co-occurring symptoms that cannot be
explained by PDD alone or ADHD alone
Grants full acknowledgement of impairments and
validates concerns
Allows for treatment plans that include the treatment
of ADHD core symptoms in PDD and PDD
symptoms in ADHD
Compensatory behaviors can be taught for ADHD Sx
Providers will pay for services in Tx of comorbidities
Others?
Dual Dx would be
inappropriate/unnecessary if:
1)
2)
3)
Inattention and hyperactivity-impulsivity in PDD cases
were due specifically to the triad of PDD impairments
(or social and communication difficulties in ADHD were
due specifically to core ADHD features)
ADHD always occurred with PDD (or visa versa)
Inattention and hyperactivity/impulsivity in PDD
differed qualitatively from ADHD as defined by DSMIV-TR
OR
Social and communication difficulties in ADHD differed
qualitatively from PDD as defined by the DSM-IV-TR
Discussion:
Based on your different experiences
with kids with ADHD/PDD, how
would you like to see the DSM-V
approach these two disorders?
Questions?