CAST: Childhood Autism Spectrum Test

About the CAST

The Childhood Autism Spectrum Test (CAST), originally called the Childhood Asperger Syndrome Test, was developed at the Autism Research Centre, University of Cambridge. It is a parent-completed questionnaire intended for use in community and school settings to identify children who may have autism spectrum characteristics.

The CAST was developed in response to the underidentification of autism in children who do not present with significant intellectual disability. It aims to capture the broader autism phenotype, including children whose social and communicative differences are subtle enough to go unrecognized in standard developmental checks.

The tool covers a broad range of behaviors across social communication, play, and routine domains, drawing on DSM and ICD criteria relevant to autism spectrum conditions.

What the Assessment Measures

The CAST evaluates autism-related characteristics across:

• Social and peer interactions, difficulty initiating or maintaining friendships, reduced interest in other children
• Communication, unusual language use, difficulty with conversational reciprocity
• Play and imagination, preference for solitary, repetitive, or rule-bound activities
• Routines and flexibility, insistence on sameness, distress at change
• Motor and sensory features, unusual sensory responses, motor stereotypies

Population and Format

• Ages: 4–11 years
• Respondent: Parent or primary caregiver
• Items: 37 yes/no questions
• Administration time: Approximately 10 minutes
• Setting: Community, school, or clinical screening

Scoring

The CAST yields a total score (range 0–31 scoreable items; 6 items are not scored).

Recommended cutoff (Scott et al., 2002):

• Score <15: Does not rule out autism spectrum conditions; clinical judgment is required

The CAST is intended as a screening tool only and does not provide a diagnosis. A positive screen should prompt a referral for comprehensive assessment.

Psychometric Properties

The CAST has been validated across multiple languages and cultural contexts:

• Good sensitivity and specificity at the ≥15 threshold in population-based samples
• Strong test-retest reliability in clinical and community settings
• Validated translations include Spanish (Morales-Hidalgo et al., 2017), Mandarin Chinese (Sun et al., 2013), and others

Clinical Considerations

• The CAST identifies children across the full autism spectrum, not only those with intellectual disability or classic autistic presentations
• Girls and children who mask autistic traits may score below the cutoff despite meeting diagnostic criteria; the CAST should be interpreted alongside direct observation and developmental history
• A negative screen does not preclude further evaluation if clinical concern remains

Who the CAST Is For

The CAST is appropriate when:

• A parent, teacher, or clinician has concerns about a child aged 4–11
• The clinical question involves autism spectrum characteristics, social communication difficulties, or restricted/repetitive behaviors
• Population-level or school-based autism screening is being conducted

References

• Scott FJ, Baron-Cohen S, Bolton P, Brayne C. (2002). The CAST (Childhood Asperger Syndrome Test): Preliminary development of a UK screen for mainstream primary-school-age children. Autism, 6(1), 9–31.
• Morales-Hidalgo P, Roigé-Castellví J, Vigil-Colet A, Canals J. (2017). The Childhood Autism Spectrum Test (CAST): Spanish adaptation and validation. Autism Research, 10(9), 1529–1540. PMID: 28383173
• Sun X, Allison C, Auyeung B, et al. (2013). The Mandarin Chinese version of the childhood autism spectrum test (CAST): test-retest reliability. Research in Developmental Disabilities, 34(10), 3267–3275. PMID: 23892873
• Sun X, Allison C, Matthews FE, et al. (2015). Exploring the underdiagnosis and prevalence of autism spectrum conditions in Beijing. Autism Research, 8(3), 250–260. PMID: 25952676