ASD: Early Signs and Developmental Patterns from Infancy

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ASD Early Signs and Developmental Patterns from
Infancy

• Rebecca Landa, Ph.D., CCC-SLP
• Kennedy Krieger Institute
• Johns Hopkins School of Medicine
• landa_at_kennedykrieger.org
• November 7, 2008

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Thank you

• To the families who participated
• To a dedicated staff
• To funding agencies (NIH MH59630, 154MH066417,
  NAAR, CAN, Coalition for Autism, Pathfinders for
  Autism)

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Objectives for Today

• The context of early detection of ASD
• Overview of prospective, longitudinal study of
  autism from infancy
• Implications for clinical practice

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Brief Overview of Autism
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Autism Impaired

• Social reciprocity
• Communication
• Stereotyped Behaviors
• Repetitive Interests
• By 36 months (Gold standard)
• (Note Autism involves any IQ, may be co-morbid
  disorders, heritable, most cases idiopathic)

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PDD Umbrella

• Pervasive Developmental Disorders
• Autism
• PDD-NOS
  CDD
• Aspergers Syndrome
  Retts Syndrome

Prevalence of ASD 1/150
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The Context of Early Detection of Autism
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Beginning the Search for Autism in Infancy

• Age at parents first concern 18 months of age
• Most parents report presence of abnormalities lt
  23 months
• Regression (mean age)
• 18 to 21months
• language and social skills
• Sensitive periods of brain development
• Capitalize on neuroplasticity
• Impact of early intervention

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But

• Autism not diagnosed until mean age 4 years
• Later in lower SES and minority racial groups

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Questions Addressed Today

• When does symptom expression begin?
• What are the early symptoms?
• What is the trajectory of development in autism
  in the first three years of life?

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Prospective, Longitudinal Study of Infant
Siblings of Children with Autism
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Participants

• Infant sibs of children with autism (n107)
• Probands met diagnostic criteria for idiopathic
  autism Autism Diagnostic Observation Scale
  (ADOS), Autism Diagnostic Interview Revised
  (ADI-R), clinical judgment
• Low risk controls (n18)
• Children were tested at target ages 6, 14, 18,
  24, 30, and 36 months of age
• Outcome testing at 30 or 36 months

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Diagnostic Outcome Groups for Au sibs

• ASD meet on ADOS Clinical judgment n30
• These were further subdivided into
• Early ASD Diagnosis (n16) Diagnosed at 14
  months of age
• Later ASD Diagnosis (n14) Diagnosed after 14
  months of age
• Broader Autism Phenotype (BAP Language and/or
  Social delay) n19
• Non-BAP n58

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Measures and Analyses

• Contingency learning task (6 months of age)
• Communication and Symbolic Behavior Scales
  Developmental Profile (14, 18, 24 months)
  (Wetherby Prizant, 2002)
• Mullen Scales of Early Learning (all ages)
  (Mullen, 1995)
• Preschool Language Scale (14-36 months)
  (Zimmerman et al., 1991 2002.
• ADOS (14-36 months) (Lord et al., 1999)
• ADI-R (outcome visit only) (Rutter et al., 2003)

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When does symptom expression begin?A look at
infants at 6, 14 and 24 months of age
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6-Month-Olds
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At 6 months of age

• At 6 months, in everyday situations, social
  domain usually appears rather intact
• Passivity
• Some delay in milestones (babbling, motor)
• Poor postural control, atypical movements (differ
  from child to child)
• In a challenge task, differences more pronounced
  affect attenuation, increased attention to
  objects, increased sticky attention, decreased
  diversity of action patterns, decreased
  vocalizations, decreased socially directed
  behavior

Bhat, Galloway, Landa under review Flanagan
Landa (2007). OTAC
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What are the patterns of developmental trajectory?
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Patterns of Trajectory

• Early Onset diagnosable ASD by 14 months
• Later Onset diagnosed after 14 months (but not
  clean at 14 months)

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Mullen Early Learning Composite
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Early Dx ASD Group

• Differed from all groups at 14 months (pslt0.01)
  
• Initiation of behavior regulatory acts
• Diversity of gestures
• Diversity of consonants
• Frequency of triadic gaze
• Initiation of joint attention
• (SPA differed from other AU sib groups but not
  cntrl)
• Also, differed from non-ASD groups at 24 months.

Landa, Holman, Garrett-Mayer. Archives of
General Psychiatry, 2007
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Later Dx Group

• No difference from non-ASD groups at 14 months.
• At 24 months, performed like early dx group
  except for frequency of triadic gaze and variety
  of consonants in syllables.
• Landa, Holman, Garrett-Mayer. Archives of
  General Psychiatry, 2007

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Communication trajectory 14-24 months
Variety of Gestures
Variety of words
Landa, Holman, Garrett-Mayer. Archives of
General Psychiatry, 2007
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Social Trajectories
Frequency of initiation of joint attention
Frequency of shared positive affect
Landa, Holman, Garrett-Mayer. Archives of
General Psychiatry, 2007
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Practical Considerations
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When there are parent concerns in children
younger than 14 months

• Have child seen by an expert in infant
  development and a physician who is experienced
  with DD and infants
• Is there a family history of ASD?
• Recommend enrichment or intervention if problems
  with
• motor coordination,
• delayed motor milestones
• postural control (incl head lag),
• atypical movements (incl tremulousness),
• attenuated affect,
• sticky attention
• delayed babbling,
• poor social orienting,
• low levels of active engagement

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For children aged 14 months and older

• Same as previous slide plus
• Screening (18, 24, 36 months) with phone
  follow-up
• Using standardized and non-standardized measures
• Communication with parents
• Recommending intervention or enrichment if
  warranted
• Close follow-up

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Stay tuned for more

• About diagnostic boundaries
• Stability of early diagnosis
• Very early interventions
• Outcomes

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STAART Toddler Tx study (n49)
Gain6 in 6 m
Gain8 In 10m
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Concluding Remarks

• Continuum of scores in AU sibs suggest presence
  of continuously, rather than discretely,
  distributed traits in families with genetic risk
  for ASD
• Major challenge cross-domain coordination,
  inflexible patterns of behavior
• ASD appears to have a progressive phase
  involving developmental arrest, slowing, and even
  regression in social and/or language systems

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Conclusions

• Earliest signs may not be the old standbys
  (motor and language milestones)
• ASD diagnosable in some, not all, children at 14
  months of age
• Verbal aspects of communication, and frequency of
  intentional communication bids have different
  trajectory than nonverbal communication and
  social
• Social gains are minimal between 14 24 m in
  children with ASD
• Implications
• Need ongoing developmental surveillance through
  at least 36 months
• Screening should avoid concepts such as lack of
  skills
• Intervene early
• Focus on interpersonal synchrony, diversity,
  active engagement with the world