Unfortunately there is yet to be a definitive test or group of tests for autism despite the above reported findings by imaging studies. Many serologic tests, imaging exams and genetic studies are geared at ruling out other conditions that may mimic autistic disorders. In general, autism is diagnosed by a health professional who is experienced in administering standardized tests geared at the areas of emotional, social and communicative dysfunction. These include Childhood Autism Rating Scale (CARS), Autism Diagnostic Checklist Form E-2, Checklist for Autism for Toddlers (CHAT), modified CHAT, PDD Screening test 2, Autistic Diagnostic Observation Scale (ADOS), and Autistic Diagnostic Review-Revised. If your child is suspected of having autism, getting to a qualified professional as soon as possible is crucial since early intervention can have major benefits.