Testing for Asperger's Syndrome typically takes a litany of tests because there is not one conclusive test that can lead to a diagnosis. In most cases, the test will include a psychological assessment, a communication assessment, and a psychiatric examination. Often, testing for Asperger's may specifically include an intelligent quotient (IQ) test, the Childhood Autism Spectrum (CAST) test, the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition test (DSM-IV), and the Asperger quotient test (AQ test).
For the psychological assessment, one of the first tests often undertaken is an IQ test. This test is common in testing for Asperger's because many of those who have, or who may have, the condition display a normal level of intelligence. While it may not rule out Asperger's if a lower IQ is discovered, the presence of a normal IQ means the other possibilities are severely limited.
The psychological assessment also encompasses many of the other personality assessment tests when testing for Asperger's. The DSM-IV, CAST test, or AQ test could be part of the process. Some doctors or medical professionals may feel the DSM-IV test has become outdated, last updated in 1994, long before a great deal of research was done into autism. Some tests, such as the CAST test, may be good both for higher-functioning levels of autism, such as Asperger's, and lower-functioning levels.
Another one of the assessments undertaken in testing for Asperger's is a communication assessment. This test is very important because one of the primary ways Asperger's and other autism spectrum disorders show themselves is through communication problems. Children or adults may be tested to see how well they communicate thoughts and ideas, both verbally and in written form, if the individual has that ability to write. The evaluation will be scored by a psychologist often specializing in communication issues.
The other test that is often done is a psychiatric evaluation. While the psychiatrist may make ask some questions, this evaluation is most commonly done through observation. In particular, some of the things the evaluator will be looking for include repetitive behaviors, problems relating or socializing with others of the same age, and whether any inappropriate or out of place emotional outbursts occur.
Once all the assessments have been completed, each will be scored. It is highly unusual for the results of a single test to be the basis for a diagnosis of Asperger's Syndrome. Evaluators may seek other explanations if one test scores low, but others seem to be within normal parameters. Testing for Asperger's may take more than one day because of all the tests involved, especially if the patient is younger.