Transcript Cleveland.Talk.1.For.Distribution

Early Assessment
and Diagnosis of
Autism Spectrum Disorders
Zachary Warren, PhD
Vanderbilt Kennedy Center / TRIAD
Department of Psychiatry / VUMC
Overview

The diagnosis of autism
• Behavioral and diagnostic features
• Etiology
• Clinical course

Reasons for early identification of
autism

Accuracy of early diagnosis

Earliest behavioral signs of autism

Clinical applications:
• Early screening and diagnosis
Acknowledgements



Wendy Stone, Ph.D.
Jeremy Veenstra-VanderWeele, M.D.
VKC / TRIAD
The diagnosis of
ASD is
behaviorally based
There are at
present no specific
medical tests or
biological markers
that indicate the
presence of autism
Autism Spectrum Disorders (ASDs)
Social Interactions
ASD
Interests and
Activities
Communication
Major Diagnostic Features for DSM-IV
Pervasive Developmental Disorders
Feature
Autistic
Disorder
Asperger’s
Disorder
PDD-NOS
Social impairment
X
X
X
X
Xa
X
X
X
Xa
Lang/ Communication disorder
Repetitive interests & activities
Onset prior to 36 months
Average intelligence
a=At least one of these two features must be present
X
May also see…



Intellectual disability
Sensory sensitivity
Coordination problems
• Fine motor and large motor skills

Savant skills
• Preserved area of function



Seizure disorder
Gastrointestinal symptoms
Sleep difficulties
Prevalence

Old estimate for autism:
• ~ 1/2000

Recent estimates for autism:
• ~ 1/500

Newest estimates for ‘autism
spectrum disorders’:
• 1/150 (1/94 boys)

CDC, 2006
Why is diagnosis increasing?
Atypical Behaviors/Sameness/Rigidity
Social Reciprocity
Autism
Asperger’s
PDD
Language/Communication
Why is autism diagnosis
increasing?

New diagnostic measures
• Autism Diagnostic Interview (1989, revised
1994)
• Autism Diagnostic Observation Schedule
(1989, generic 2000)

Awareness
• Mental health providers, pediatricians,
schools
• Media, parents


Previous underestimates
Other factors???
A broad spectrum?
Constantino, JAACAP, 2003
Clues to autism causes


Maleness (3:1)
Heritability
• Twin studies of shared diagnosis:
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Identical  60-90%
Fraternal  0-50%
• Family studies:
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Siblings  3-20%
General population risk  0.2-0.7%
Clues to autism causes

Lack of specific environmental causes
• No single pathologic event has been uniquely
or universally associated with autism
• Controversies do exist: vaccines, metals,
toxins, diets
• Pseudoscience also prevalent: television,
historical family factors (i.e., refrigerator
mothers)
Genes in autism

Common theme:
synapse
development
• Common variants:
MET
• Uncommon
variants: SERT
• Mutations: NLGN4,
NRXN1
• Association:
GABRB3, EN2,
SLC25A12…
Polygenic inheritance?
Autism
Anxiety Risk
Intense Focus
Atypical
Autism
Relatively simple genetic examples
Maternal chromosome 15q11-13
duplication or triplication
Fragile X (0.5-3%)
Rett, Tuberous sclerosis
distal 2q deletions
NLGN4 mutations
Note: Circles represent gene effects
Cook, 2000
Language
Impairment
Risk and Susceptibility Genes
Autism
Aa
aa
Risk
Bb
bb
Genes
cc
cC
Dad
Son with
ASD
Mom
Daughter
Aa
aa
Bb
Bb
cC
cc
Course/Outcome

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Complex neurodevelopmental disorder
Social and communication deficits in first
years of life
Outcome is highly variable
Best predictors of outcome are cognitive
and language skills
Prognosis is much more positive than
earlier research indicated
Course/Outcome
Previous
Samples
More Recent
Samples
Average
Intelligence
25%
50%
Functional
Language
50%
75%
Adult
Independence 15-20%
?
Why is it important to identify
autism at young ages?
• for the child
• for the family
• for science
• for society
Reasons for Early ID
1. To optimize child outcomes


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Early diagnosis 
specialized early intervention
Specialized intervention 
improved social, behavioral,
cognitive, & language
functioning
Capitalize on increased brain
plasticity
Models of Developmental Outcomes
Reasons for Early ID
2. To educate & empower families




Alleviate parental
uncertainty
Provide access to
resources & support
Foster networking &
advocacy
Clarify genetic
implications
Reasons for Early ID
3. To understand causes and
improve treatments

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Identify core features
Define etiological
subtypes
Delineate
developmental
pathways &
sequences
Develop tailored
treatments
Reasons for Early ID
4. To increase societal engagement
decrease system demands
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Not a rare disorder
System demands and
problems can be
extensive
Effective early
intervention can
reduce individual,
family, system, and
societal costs
Current Practice Guidelines
recommending early identification
and intervention
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American Academy of Neurology (2000)

National Academy of Sciences (2001)
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American Academy of Pediatrics (2001)
• Autism A.L.A.R.M. (2004)
American Academy of Pediatrics (2006)
• Developmental Surveillance and Screening
American Academy of Pediatrics (2007)
• 18 and 24 months
Challenges of Early Diagnosis

Increased behavioral variability at
young ages
• Behavioral variability across children
• Behavioral variability across time
• Behavioral variabilitiy across settings

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Overlapping symptoms with other
developmental disorders (e.g.,
developmental delay, language
delay/disorder)
Decreased applicability of current
diagnostic systems
How accurate is the early
diagnosis of autism?
• Reliability across
clinicians
•Stability over time
Reliability Across Clinicians

Good agreement between
experienced clinicians at age 2
- ASD vs. Nonspectrum = 89% (K = .69)
- Autism vs. PDD-NOS = 81% (K = .63)

Lower agreement for inexperienced
- especially for Autism vs. PDD-NOS
Dx Stability Over Time

Age 2 diagnosis is stable over time
• Greatest stability from 30 months on

Higher stability:
• Autism  Autism

Lower stability:
• PDD-NOS  PDD-NOS

“Leaving the spectrum”
• 15% “leave” the autism spectrum
 Retain a developmental difficulties?
Accuracy of Early Diagnosis
WHAT WE KNOW
• Reliable across clinicians
• Stable over time…
…as young as
24 months
WHAT WE DON’T
KNOW
• Accuracy of diagnosis
under 24 months
What are the earliest behavioral
features of autism?
Autism Spectrum Disorders (ASDs)
Social Interactions
ASD
Interests and
Activities
Communication
Autism Spectrum Disorders (ASDs)
Social Interactions
ASD
Interests and
Activities
Communication
Typical Social Development
•Show enjoyment in social giveand-take
•Direct affective expressions to
others
•Like to please adults
• Initiate teasing games
• Show interest in peers
• Imitate actions of peers
Qualitative Impairment in Social Functioning
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Atypical nonverbal social behavior
• Gaze, range of facial expressions, social smiling,
pointing
Failure to develop peer relationships
• Interest in peers, response to peers
Shared enjoyment
• Joint/directing attention, bringing, showing, sharing
Lack of social emotional reciprocity
• Hand as tool, lack of response to distress,
inappropriate facial expressions, limited back and
forth play, poor response to name, limited response
to social approach of others, limited insight and
understanding of emotions/experiences of others.
Hallmark feature!!!
Social Red Flags
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Less responsive to social
overtures
Less participation in back-andforth play
Less “showing off” for attention
Less imitation of the actions of
others
Less interested in other children
Parental Descriptions of
Social Behaviors
“It’s hard to get his attention”
“He seems to be in his own world”
“Everything he does is on his own terms”
“He completely ignores his baby sister”
But also….
“He’s very affectionate”
“He loves to wrestle with his dad”
Social behavior is not
all-or-nothing
• Social behaviors are not completely absent
(despite DSM wording)
• Children with autism do show social behaviors
(e.g., eye contact, imitation, attachment)
• Social behaviors occur less consistently
across people and settings (e.g., at different
times, requiring greater effort)
Autism Spectrum Disorders (ASDs)
Social Interactions
ASD
Interests and
Activities
Communication
Typical Communication
Development (1)
Young children communicate for many reasons:
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To request things they want
To protest about events that displease them
To share their enjoyment with adults
To direct adult’s attention to objects or events of
interest
Typical Communication
Development (2)
Young children use verbal & nonverbal
behaviors to communicate

Gestures

Eye contact

Facial expressions

Vocalizations
Qualitative Impairments in
Communication

Absence of language / Language delay without
nonverbal compensation
• Milestones atypical, little gestural communication, little
spontaneous communication, regression

Stereotyped, repetitive, or idiosyncratic speech
• Echolalia, pronominal reversal, pop-up phrases, odd jargoning,
neologisms

Lack of spontaneous make-believe or social
imitative play
• Limited imitations, limited fucntional play, limited doll play
For verbal subjects:
 Failure to sustain conversational interchange
• Limited social chat/comments, limited back and forth interchanges
Most commonly recognized early impairment:
Delayed / disordered language development
Communication

Communication Process itself seems to
be impaired/atypical*
• Communication is the conveyance
• Language is the tool
Different ways to get what you want
Eye contact
& Gesture
Language Red Flags
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No babbling, pointing, or other
gestures by 12 months
No single words by 16 months
No spontaneous two-word phrases by
24 months
Loss of language skills at any age
Source: AAN Practice Parameters
Communication
Red Flags
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Less communication to direct
another person’s attention
Less use of gestures to
communicate
Less use of eye contact to
communicate
Inconsistent response to
sounds/name
Parental Descriptions of
Communication Behaviors
“He gets things by himself”
“He can’t tell me what he wants”
“He takes my hand and pulls me to
whatever it is he wants”
“He repeats lines and songs from videos
but doesn’t use words to ask for things”
“We thought he couldn’t hear”
Autism Spectrum Disorders (ASDs)
Social Interactions
ASD
Interests
and
Activities
Communication
Typical Play Activities
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Play with a variety of
toys
Use toys functionally
and flexibly
Create a variety of
different play
schemes
Act out real-life
scenes with toys
Restricted Repetitive and Stereotyped
Behavior
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Preoccupations/Interests
• Repetitive play, unusual interest in specific objects,
preferred object
Inflexible adherence to non-functional routines
• Distress around routing changes, toys in specific
locations, repeats sequences, requires others to
complete sequences
Stereotyped motor mannerisms
• Tensing/posturing, flapping, finger flicking, rocking,
bouncing
Preoccupation with parts of objects
• Repeated activation of toys, spinning, switches,
visual inspection, sensory interests/vulnerabilities
Examples of Restricted Activities
Parental Descriptions of
Restricted Activities
“He plays with all of his toys by lining
them up”
“He studies things very carefully”
“He plays by dumping his blocks and then
putting them back again – over and over”
“He likes to drop objects and watch them
fall”
Restricted Activities/Interests
Red Flags
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Less functional play,
especially with dolls
Less imaginative play
Possibly: repetitive motor
behaviors, unusual visual interests
Early Symptoms of Autism
Behavioral
symptoms in the
social and
communication
domains are the
most reliable early
indicators of autism
Early Symptoms of Autism
Behavioral symptoms in
the domain of restricted
and repetitive interests
are not reliable
indicators of autism in
very young children
Challenges in Identifying
Social-Communicative Deficits
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Negative symptoms
Behaviors are demonstrated
inconsistently, not totally absent
Parents are good at scaffolding
Lack of clear expectations for
social milestones, “social
reciprocity”
Differential Diagnosis of ASD
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
Developmental considerations may limit our
ability to provide definitive diagnosis (i.e.,
extremely young children, differing
developmental trajectories).
The state of our science limits the ability of
even top clinicians to provide definitive
diagnosis in certain situations.
• May need more information from additional
sources.
• May need to monitor development.
• May need further evaluation.
Differential Diagnosis of ASD in
young children
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Anxiety disorders
Global developmental delays
Speech and language delays
Sensory impairment (hearing loss)
Severe behavior dysregulation
Profound psychosocial challenges
Medical rule-outs
Diagnostic Formulation

Diagnosis must weigh considerations of atypical
development with typical developmental variability.

Diagnosis suggests impairment across numerous
domains in numerous situations.

Integrating information from multiple sources is
important.

Variability within profiles is to be expected as social and
communicative behaviors are not all-or-none.

Evaluations of consistency, flexibility, spontaneity,
quality, and context are crucial.
Clinical Applications:
Early Screening and Diagnosis
Autism-Specific Screening Measures
for children under 3 years old
CHAT
18m
STAT
Baron-Cohen et al.,
1992; 1996
Stone et al., 2000; 2004
M-CHAT
Robins et al., 2001
18/24m
CHAT-23
Wong et al., 2004
MA>18m
24/14m
PDDST-II Siegel, 2004
18m
ESAT
14m
Swinkels et al., 2006
Screening Measures
for children under 3 years old
Stage 1
(primary care)
Stage 2
(referral)
Parental
Report
M-CHAT
PDDST-II
ESAT
PDDST-II
Interactive
CHAT*
CHAT-23*
STAT
* Also include parent report items
Screening
is
important
only if
something
happens
next
Components of Gold Standard
Assessment
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Medical assessment
Autism Diagnostic Interview – Revised (ADI-R)
• Structured clinical interview
• 90-180 minutes
Autism Diagnostic Observation Schedule (ADOS)
• Semi-structured interaction
• 45 minutes / 15 minutes scoring
Developmental assessment
• Cognitive/IQ
• Language
• Adaptive behavior
Components of Gold Standard
Assessment
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Medical assessment:
• Sensory rule-outs
• Co-occuring/contributing conditions
• Neurodevelopmental and family risk
Developmental assessment:
• Overall level of functioning
• Core areas of difficulty that may not be
ASD specific
• Clinical impression as linked with
intervention function
Components of Gold Standard
Assessment


ADI: Structured clinical interview
• Developmental history and current
functioning
 Parent
 Teacher
ADOS: Structured interaction / observation
• Anchor and inform developmental reports
• More contexts the better
Assessment Best Practices for
Young Children

Gold-standard assessment in preschool
• Medical and genetic workups

Developmental Evaluation
• Adaptive behavior (VABS-II)
• Language (PLS, EVT, PPVT, Reynell)
• Cognitive performance (DAS-II, Mullen, Bayley)

Structured Interview and Parent/Teacher Report
of ASD symptoms
• ADI or variant

Diagnostic Observation
• ADOS / STAT
General
Approaches to
Diagnostic
Assessment of
ASD in Young
Children
Different types
of information
are available
from clinical
observations
vs. parental
reports vs.
teacher
reports
Information available from
parental/teacher report

Interactions with peers

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Imaginative play
Setting-specific or rare
behaviors
(e.g., adherence to routines; stereotyped
body movements)

Language regression
Information available from
clinician observations

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Subtle aspects of social
relating
and reciprocity
Subtle deficits in nonverbal
communication
Markers in relation to typical
and atypical development
Tools

Structured Interview and Parent Report
• Numerous screening questionnaires

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CHAT, M-CHAT, PDDST-II
ABC, CARS, GARS, PDDST, STAT, SCQ
• These scores and psychometric properties of
the above suggest that gathered information /
scores from self-report should not stand alone
• Interviews provide structure surrounding
developmental expectations
Eliciting
Information
Ask for examples
and details
• How / What does s/he do?
• How often does she…
• In what settings does this
occur?
• Does this happen spontaneously?
• How hard do you have to work to see this
response)?
• Does this happen with familiar and unfamiliar
people?
Eliciting Information



Comment on
observed behavior
to anchor both
involved.
*e.g. speaking the
same language*
Use the family’s
words.
Refer to their
examples,
descriptions.
Eliciting Accurate Information
from Diagnostic Interviewing

Provide response gradients rather
than:
“yes/no”
“absent/present”
“always/never”

Concrete markers

The diagnosis is in the details
The state of things…

We can identify core differences in
young children that appear to be
meaningful in that they are stable
over time and can link children with
appropriate intervention services.
Challenges of Early Assessment
and Diagnosis


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Limited availability of community resources
• Diagnosticians
• EI providers with autism expertise
• Educational and behavioral providers
Limitations in knowledge
• Diagnosis under 24 months
• Qualitative differences in social-emotional
behavior
• Developmental implications
• Specific effective components of interventions.
Need for complex medical and behavioral
management following screening and
diagnosis
Future Directions for Early
Identification Research


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
Examine stability of autism diagnosis
under 24 months
Identify optimal approaches to screening,
evaluation, and diagnosis
Develop and evaluate new approaches to
early intervention and prevention
Identify methods for training community
service providers to meet service need.