CASD (Checklist for Autism Spectrum Disorder)

The CASD evaluates 30 symptoms of autism spectrum disorder across six domains:

• Problems with social interaction
• Perseverations (persistent or frequent repetition of a word, thought, melody, or action)
• Somatosensory disorders
• Atypical communication and development
• Mood
• Problems with attention and safety

Symptoms are assessed as present or absent based on information obtained from a variety of sources, including teachers, caregivers, parents, observations of the child, and available records.

The CASD is the only diagnostic tool designed to assess autism spectrum disorders on a single spectrum, unlike other methods that assess disorders by subtypes. Each DSM-5 criterion has a correspondence among the symptoms in the questionnaire, including the proposed criteria related to sensory impairment.

Because of its brevity and simplicity, all children referred for diagnosis of ASD or developmental, behavioral, or other mental health problems can be tested with the CASD to rule out or confirm ASD. Similarly, all young children who receive early intervention services can be screened for possible ASD using the CASD. This is especially important for young children, who are often not diagnosed with ASDs because they simply have not been evaluated. Research shows that almost all children with ASD have attention deficit hyperactivity disorder (ADHD), and children with ASD are often initially diagnosed with ADHD only and are not recognized as having an ASD until much later.