Tuesday, August 31, 2010

Evidence-Based Screening for Autism Spectrum Disorders

Epidemiological studies indicate a progressively rising prevalence trend for ASD over the past decade. Yet, compared with general population estimates, children with mild to moderate autistic traits remain an underidentified and underserved population in our schools. There are likely a substantial number of children with equivalent profiles to those with a clinical diagnosis of ASD who are not receiving services. Research indicates that outcomes for children on the autism spectrum can be significantly enhanced with the delivery of intensive intervention services. However, intervention services can only be implemented if students are identified. Screening is the initial step in this process. School professionals and clinicians should be prepared to recognize the presence of risk factors and/or early warning signs of ASD and be familiar with screening tools in order to ensure children with ASD are being identified and provided with the appropriate programs and services.

The following evidence-based tools have demonstrated utility in screening for ASD in educational settings and can be used to determine which children are likely to require further assessment and/or who might benefit from additional support. All measures have sound psychometric properties, are appropriate for school-age children, and time efficient (10 to 20 minutes to complete). Training needs are minimal and require little or no professional instruction to complete. However, interpretation of results requires familiarity with ASD and experience in administering, scoring, and interpreting psychological tests.
  • The Autism Spectrum Rating Scales (Short Form) (ASRS; Goldstein & Naglieri, 2009).
  • The Autism Spectrum Screening Questionnaire (ASSQ; Posserud, Lundervold, & Gillberg, 2006).
  • The Childhood Autism Spectrum Test (CAST; Williams, Allison, Scott, Stott, Baron-Cohen, & Brayne, 2006).
  • The Social Communication Disorders Checklist (SCDC; Skuse, Mandy, & Scourfield, 2005).
  • The Social Communication Questionnaire (SCQ; Rutter, Bailey, & Lord, 2003).
  • The Social Responsive Scale (SRS; Constantino & Gruber, 2005).
Of course, none of these screening measures can differentiate between the autism spectrum subtypes. A screening tool’s efficiency will also be influenced by the practice setting in which it is used. Autism-specific tools are not currently recommended for the universal screening of typical school-age children. Focusing on case finding and children with identified risk-factors and/or developmental delays increases predictive values and results in more efficient screening.

A multi-tier screening algorithm and step-by-step assessment guidelines are available from:

© Lee A. Wilkinson, PhD

Sunday, August 1, 2010

Can School Professionals Diagnose Autism?

As we prepare for the new school year, this question will be asked with ever increasing frequency. Yes. Professionals such as school psychologists and speech/language pathologists can diagnose or classify a child with an autism spectrum disorder (ASD) within the school context. The dramatic increase in the prevalence of children with ASD over the past decade, together with the clear benefits of early intervention, have created a need for schools to identify children who may have an autism spectrum condition. It is not unusual for children with milder forms of autism to go undiagnosed until well after entering school. In fact, research indicates that only three percent of children with ASD are identified solely by non-school resources. As a result, school professionals are now more likely to be asked to participate in the screening and identification of children with ASD than at any other time in the past.

The Individuals with Disabilities Education Act of 2004 (IDEA) and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV) are the two major systems used to diagnose and classify children with ASD. The DSM-IV is considered the primary authority in the fields of psychiatric and psychological (clinical) diagnoses, while IDEA is the authority with regard to eligibility decisions for special education. The DSM-IV was developed by clinicians as a diagnostic and classification system for both childhood and adult psychiatric disorders. The IDEA is not a diagnostic system per se, but rather federal legislation designed to ensure the appropriate education of children with special educational needs in our public schools. Unlike the DSM-IV, IDEA specifies categories of ‘‘disabilities’’ to determine eligibility for special educational services. The definitions of these categories (there are 13), including autism, are the most widely used classification system in our schools. According to IDEA regulations, the definition of autism is as follows:

(c)(1)(i) Autism means a developmental disability significantly affecting verbal and nonverbal communication and social interaction, generally evident before age 3, that adversely affects a child’s educational performance. Other characteristics often associated with autism are engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences. The term does not apply if a child’s educational performance is adversely affected primarily because the child has an emotional disturbance, as defined in this section.

(ii) A child who manifests the characteristics of ‘‘autism’’ after age 3 could be diagnosed as having ‘‘autism’’ if the criteria in paragraph (c)(1)(i) of this section are satisfied.

This educational definition is considered sufficiently broad and operationally acceptable to accommodate both the clinical and educational descriptions of autism and related disorders. While the DSM-IV diagnostic criteria are professionally helpful, they are neither legally required nor sufficient for determining educational placement. It is state and federal education codes and regulations (not DSM IV-TR) that drive classification and eligibility decisions. Thus, school professionals must ensure that children meet the criteria for autism as outlined by IDEA and may use the DSM-IV to the extent that the diagnostic criteria include the same core behaviors (e.g., difficulties with social interaction, difficulties with communication, and the frequent exhibition of repetitive behaviors or circumscribed interests). Of course, all professionals, whether clinical or school, should have the appropriate training and background related to the diagnosis and treatment of neurodevelopmental disorders. The identification of autism should be made by a professional team using multiple sources of information, including, but not limited to an interdisciplinary assessment of social behavior, language and communication, adaptive behavior, motor skills, sensory issues, and cognitive functioning to help with intervention planning and determining eligibility for special educational services.

Life Journey through Autism: A Parent’s Guide to Assessment. Arlington, VA: Organization for Autism Research.

American Academy of Pediatrics. Understanding Autism Spectrum Disorders [pamphlet]. Elk Grove Village, IL: American Academy of Pediatrics; 2005.

National Institute of Child Health and Human Development Autism Site

National Research Council (2001). Educating Children with Autism. Washington, DC: National Academy Press.

Wilkinson, L. A. (2010). A best practice guide to assessment and intervention for autism and Asperger syndrome in schools. London: Jessica Kingsley Publishers.

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