Pervasive Developmental Disorders (Autism Spectrum Disorders): Early Screening & Diagnostic Assessment Laura Grofer Klinger, Ph.D. University of Alabama Psychology Department December 6, 2004

Development of Screening Instruments for Early Diagnosis The earlier the intervention, the better the outcome in terms of language development, IQ, and placement in a regular education classroom.The earlier the intervention, the better the outcome in terms of language development, IQ, and placement in a regular education classroom. Increased emphasis on the development of early screening instruments that will lead to earlier intervention.Increased emphasis on the development of early screening instruments that will lead to earlier intervention.

Why is early diagnosis important? Most parents suspect that something is “wrong” by 18 months and seek medical assistance by 2 years.Most parents suspect that something is “wrong” by 18 months and seek medical assistance by 2 years. However, most diagnoses are not made until the child is 3-4 years of age.However, most diagnoses are not made until the child is 3-4 years of age. Earlier identification leads to earlier intervention.Earlier identification leads to earlier intervention. At least 2 years of intervention during preschool years leads to:At least 2 years of intervention during preschool years leads to: –Increased language development –Higher IQ –Placement in a regular education classroom.

Early Social Impairments in Autism

Early Developing Social Impairments in Autism

Diagnostic Process for Parents Concerns that may be deaf or have a hearing impairment.Concerns that may be deaf or have a hearing impairment. Concerns over their child’s lack of language development.Concerns over their child’s lack of language development. Concerns that they may have done something wrong as a parent (e.g., left the child during a trip, moved).Concerns that they may have done something wrong as a parent (e.g., left the child during a trip, moved). Decision to take the child in for a medical “test” to determine what is wrong.Decision to take the child in for a medical “test” to determine what is wrong.

Practice Parameters for the Diagnosis and Evaluation of Autism (Filipek et al., 1999) Recommend routine developmental screening by all providers at well-child visits.Recommend routine developmental screening by all providers at well-child visits. ABSOLUTE indications for immediate further evaluation (hearing test and autism screen).ABSOLUTE indications for immediate further evaluation (hearing test and autism screen). –No babbling by 12 months of age. –No pointing or other gestures by 12 months. –No single words by 16 months. –No 2 word spontaneous (not echolalic) phrases by 24 months. –ANY loss of ANY language or social skills at ANY age.

Early Screening Instruments Checklist for Autism in Toddlers (CHAT)Checklist for Autism in Toddlers (CHAT) –Designed to screen for symptoms of autism at 18 months of age. –9 item parent report; 5 item observation. –Developed for primary care settings. –Low sensitivity (i.e., it misses a lot of children). Pervasive Developmental Disorders Screening Test (PDDST)Pervasive Developmental Disorders Screening Test (PDDST) –Screen for symptoms from birth to 48 months. –Brief (25-30 item) parent report checklist. –Versions for primary care and developmental clinic settings.

Autism Diagnostic Evaluation There is no “medical” test for autism.There is no “medical” test for autism. –Genetic testing, referral to a neurologist recommended –Diagnosis is based on parent report and clinician observations. Detailed Parent InterviewDetailed Parent Interview Autism Diagnostic Interview Structured Play SessionStructured Play Session Autism Diagnostic Observation Schedule Behavioral Rating ScalesBehavioral Rating Scales Childhood Autism Rating Scale Cognitive TestingCognitive Testing Speech and Hearing EvaluationSpeech and Hearing Evaluation

Issues in Diagnostic Assessment of Pervasive Developmental Disorder Symptom profile changes across the lifespan.Symptom profile changes across the lifespan. –e.g., joint attention, repetitive interests and behaviors. Symptom presentation within the context of developmental level.Symptom presentation within the context of developmental level. –e.g., pretend play Differentiation between the subtypes of Pervasive Developmental Disorders.Differentiation between the subtypes of Pervasive Developmental Disorders.

Diagnostic Instruments Childhood Autism Rating ScaleChildhood Autism Rating Scale –Mental age greater than 36 months. –Not a lifetime diagnosis. –Developed prior to DSM-IV. –Screening instrument Social Communication QuestionnaireSocial Communication Questionnaire

Autism Diagnostic Interview - Revised Mental age greater than 18 months.Mental age greater than 18 months. 96% sensitivity, 92% specificity96% sensitivity, 92% specificity Benefits:Benefits: –Standardized instrument; good validity and reliability –Addresses changing symptom profile –Lifetime history Limitations:Limitations: –Influenced by parent perceptions/agendas –Over-diagnoses very delayed children. –No cutoff scores for non-autism PDDs. –Lengthy interview

Autism Diagnostic Observation Scale Normed on children from 15 months through 40 years.Normed on children from 15 months through 40 years. Four different modules.Four different modules. 95% sensitivity.95% sensitivity. Benefits:Benefits: –Standardized instrument with good validity and reliability –Developmentally appropriate observations. Limitations:Limitations: –Parent interview is needed for repetitive/obsessive behaviors. –Differentiation between PDDs. –Current, not life-time diagnosis.

Autism vs. Mental Retardation 40-69% of children with autism have mental retardation.40-69% of children with autism have mental retardation. Both groups show stereotyped behaviors.Both groups show stereotyped behaviors. Autism is associated with an uneven pattern of skillsAutism is associated with an uneven pattern of skills Autism is associated with impairments in social interaction and in nonverbal communication.Autism is associated with impairments in social interaction and in nonverbal communication.

Developmental Disorder vs. Developmental Delay

Giving Feedback and Parent Reactions to the Diagnosis Diagnosis not based on scores but on observations.Diagnosis not based on scores but on observations. Have the parents observe part of the assessment to insure that they saw the behaviors you are discussing.Have the parents observe part of the assessment to insure that they saw the behaviors you are discussing. Reduce focus on IQ score.Reduce focus on IQ score. Be sure to tell the parents that they didn’t cause the autism.Be sure to tell the parents that they didn’t cause the autism.