Autism has been in the news a lot lately, sparked by such studies as one recently conducted in South Korea that found the rates of autism as being more than twice those found in other studies done in the United States and other Western Countries (see this New York Times article).
Additionally, even autism rates in the United States have been found to be higher than before. Experts think that this is because medical providers and parents are now more aware of autism, but regardless of whether the rate has been increasing or not it’s clear that autistic children make up a significant part of the population and their needs must be addressed appropriately.
What is Autism?
Autism is a term used to encompass a range of disorders that include social issues and mental retardation as well as Asperger’s syndrome and other milder behavioral disorders that often aren’t diagnosed. More specifically, Autism refers to five pervasive development disorders (PDD) first diagnosed by Dr. Leo Kanner of Johns Hopkins in 1943 and Dr. Hans Asperger in Germany. These disorders are marked by social skill impairments and “restricted, repetitive, and stereotyped” patterns of behavior (see NIH).
What Causes Autism?
Autism is a biological disorder, but experts don’t know what exactly causes it. Because autism encompasses a range of disorders ranging from very severe to less severe, experts think there are likely multiple causes. Evidence suggests such factors as genetic disorders, environmental factors, and issues with the central nervous system. However, one thing that is NOT the cause of autism is bad parenting, an incorrect cause first suggested by Leo Kanner, the psychiatrist who first described autism.
What is the Prevalence of Autism?
According to the National Institutes of Health,
the Center for Disease Control in its most recent metropolitan survey found that autism occurs in every 3.4 per 1,000 children. This rate is higher than the rates initially estimated from studies done in the 1980s and 1990s. A recent six year study in the South Korean city of Goyang found a figure might higher at 2.6% of children. The CDC believes prevalence lies somewhere between 2 to 6 children per 1,000, and rates may increase in the future not because there are more autistic children but because more people are aware of autism and its symptoms.
How is Autism Diagnosed?
Medical professionals look at behavioral characteristics in order to diagnose whether a child has autism. The diagnosis involves two steps:
Step 1: Screening
In this step, the clinician conducts a developmental screening test during a “well child” check-up. Screening tests that might be used include the Checklist of Autism in Toddlers (CHAT), the modified Checklist for Autism in Toddlers (M-CHAT), the Screening Tool for Autism in Two-Year-Olds (STAT), or the Social Communication Questionnaire (SCQ) for children aged four and older. Some of these may be based on responses parents provide to a questionnaire, while others may be conducted by the clinician.
There are also screening tests for Aspergers and “higher functioning” autism. These include the Autism Spectrum Screening Questionnaire (ASSQ), the Australian Scale for Asperger’s Syndrome, and the Childhood Asperger Syndrome Test (CAST).
Step 2: Comprehensive Diagnostic Evaluation
In this step a more comprehensive evaluation is performed to rule out other developmental problems. The professionals involved in this step of the evaluation may include psychologists, neurologists, psychiatrists, speech therapists, and others. This step should include neurologic assessment, genetic assessment, and cognitive and language tests. Other formal tests for autism may also be used including the Autism Diagnosis Interview-Revised (ADI-R), the Autism Diagnostic Observation Schedule (ADOS-G), and the Childhood Autism Rating Scale (CARS).
Two tests that should also be done include a hearing evaluation and a lead screening. The NIH states that children with autism often have elevated blood lead levels.