Autism Spectrum Disorder
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What are the Characteristics of Autism Spectrum Disorders?
Each of the disorders on the autism spectrum is a neurological disorder that affects a child’s ability to communicate, understand language, play, and relate to others. They share some or all of the following characteristics, which can vary from mild to severe:
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Communication problems (for example, with the use or comprehension of language);
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Difficulty relating to people, things, and events;
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Playing with toys and objects in unusual ways;
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Difficulty adjusting to changes in routine or to familiar surroundings; and
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Repetititive body movements or behaviors.
These characteristics are typically evident before the age of three.
Children with autism or one of the other disorders on the autism spectrum can differ considerably with respect to their abilities, intelligence, and behavior. Some children don’t talk at all. Others use language where phrases or conversations are repeated. Children with the most advanced language skills tend to talk about a limited range of topics and to have a hard time understanding abstract concepts. Repetitive play and limited social skills are also evident. Other common symptoms of a disorder on the autism spectrum can include unusual and sometimes uncontrolled reactions to sensory information—for instance, to loud noises, bright lights, and certain textures of food or fabrics.
What are the Specific Disorders on the Autism Spectrum?
There are five disorders classified under the umbrella category officially known as Pervasive Developmental Disorders, or PDD. As shown below, these are:
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autism;
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Asperger syndrome;
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Rett syndrome;
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childhood disintegrative disorder; and
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Pervasive Developmental Disorder Not Otherwise Specified (often referred to as PDDNOS).

Although there are subtle differences and degrees of severity between these five conditions, the treatment and educational needs of a child with any of these disorders will be very similar. For that reason, the term “autism spectrum disorders”—or ASDs, as they are sometimes called— is used quite often now and is actually expected to become the official term to be used in the future (see the section below called “A Look at ASD Diagnoses in the Future”).
The five conditions are defined in the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR) of the American Psychiatric Society (2000). This is also the manual used to diagnose autism and its associated disorders, as well as a wide variety of other disabilities.
At the moment, according to the 2000 edition of the DSM-IV, a diagnosis of autistic disorder (or “classic” autism) is made when a child displays 6 or more of 12 symptoms across three major areas:
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social interaction(such as the inability to establish or maintain relationships with peers appropriate to the level of the child’s development,
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communication (such as the absence of language or delays in its development), and
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behavior (such as repetitive preoccupation with one or more areas of interest in a way that is abnormal in its intensity or focus).
When children display similar behaviors but do not meet the specific criteria for autistic disorder, they may be diagnosed as having one of the other disorders on the spectrum—Aspergers, Rett’s, childhood disintegrative disorder, or PDDNOS. PDDNOS (Pervasive Developmental Disorder Not Otherwise Specified) is the least specific diagnosis and typically means that a child has displayed the least specific of autistic-like symptoms or behaviors and has not met the criteria for any of the other disorders.
Terminology used with autism spectrum disorders can be a bit confusing, especially the use of PDD and PDDNOS to refer to two different things that are similar and intertwined. Still, it’s important to remember that, regardless of the specific diagnosis, treatments will be similar.
What Causes an ASD?
The causes of autism and the other disorders on the spectrum are not known. Researchers are currently studying such areas as neurological damage and chemical imbalances within the brain. These disorders are not due, however, to psychological factors or, as has been widely reported in the press, to childhood vaccines.
Tips for Parents
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Learn about autism spectrum disorders—especially the specific disorder of your child. The more you know, the more you can help yourself and your child. Your state’s Parent Training and Information Center (PTI) can be very helpful. You’ll find your PTI listed on NICHCY’s State Resource Sheet(under “Organizations Especially for Parents”). We’ve also listed organizations at the end of this fact sheet that can help you become knowledgeable about your child’s disorder.
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Be mindful to interact with and teach your child in ways that are most likely to get a positive response. Learn what is likely to trigger a melt-down for your child, so you can try to minimize them. Remember, the earliest years are the toughest, but it does get better!
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Learn from professionals and other parents how to meet your child’s special needs, but remember your son or daughter is first and foremost a child; life does not need to become a neverending round of therapies.
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If you weren’t born loving highly structured, consistent schedules and routines, ask for help from other parents and professionals on how to make it second nature for you. Behavior, communication, and social skills can all be areas of concern for a child with autism and experience tells us that maintaining a solid, loving, and structured approach in caring for your child, can help greatly.
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Learn about assistive technology (AT) that can help your child. This may include a simple picture communication board to help your child express needs and desires, or may be as sophisticated as an augmentative communication device.
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Work with professionals in early intervention or in your child’s school to develop an IFSP or an IEP that reflects your child’s needs and abilities. Be sure to include related services, supplementary aids and services, AT, and a positive behavioral support plan, if needed.
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Be patient and stay optimistic. Your child, like every child, has a whole lifetime to learn and grow.
http://nichcy.org/disability/specific/autism/