Autism Spectrum Disorders


Asperger Syndrome is one of five “Pervasive Developmental Disorders” (PPDs). Some authors refer to them as “Autism Spectrum Disorders.”

A “spectrum disorder” has a wide variety of mild to severe symptoms in many different combinations. This means that each affected person is different and has individual symptoms. Autism is a spectrum disorder along with fetal alcohol syndrome, Obsessive-Compulsive Disorder and so forth.

The reason doctors call disorders “pervasive” is they affect every aspect of the child’s development: educational, social, emotional and physical. People are born with PPDs: it is not something caused by parenting. At this point, scientists do not fully understand the genetics of PPDs and have found no cure for them. However, experts in the field are constantly finding promising new ways of treating, educating, and rehabilitating people with PPDs.

The ratio of boys with autistic spectrum disorders is four times that of girls. The five PPDs occur equally in all racial, cultural and socio-economic groups. The incidence is about 3.4 and 6.7 per 1,000 children, according to the United States Center for Disease Control. In the United States, autism is increasing by 10 to 17 percent per year.

Diagnosing Pervasive Developmental Disorders

It is difficult for professionals to diagnose any kind of childhood mental or developmental disorder. Usually they work from reports by teachers and parents. Even doctors mistake PPDs for attention deficit, bipolar, oppositional defiant, conduct, language or communication disorders. These and mental illnesses like depression and childhood schizophrenia all have similar symptoms that sometimes overlap. Sadly, some children receive more than 15 diagnoses before they find the correct one.

Correct diagnosis is important because there are specific interventions and teaching methods for parents and educators to use for each condition. Each disorder has its own support groups, advocacy organizations, educational tools, specialists, and even specialized schools and camp programs.

All five PPDs have three common symptoms:

  • Impaired social interaction.

    Some autistic people do not seem to understand the difference between people and objects. Others can be very affectionate, yet have trouble relating to others because they cannot understand social cues and body language. One frequent symptom is the inability to enjoy mutual interests and experiences with other people. Another very common trait is the inability to make eye contact.

  • Impaired communication.

    Many severely autistic people never learn to speak at all. However, high-functioning autistic children often speak articulately and with erudition. Unfortunately, they may never master the “give and take” aspect of true communication. Most people who suffer from a PPD do not understand symbolic speech or gestures nor can play “make believe.”

  • Odd or stereotyped behaviors.

    Some autistic people demand routines and rituals and become extremely agitated if their “rules” are not followed. They may cling to certain objects or items of clothing. There may be unusual body movements that seem to be self-soothing, such as rocking, head banging, or hand wringing. These are called “stereotyped behaviors.”

Here is a list of the five PPDs. The first two are extremely rare and sometimes not included as “Autism Spectrum Disorders.”

1) Rett’s Syndrome affects only girls. It was discovered only in 1966 by Austrian Dr. Andreas Rett. Scientists believe that it is not inherited but caused by a random genetic mutation. Babies with Rett’s start out normally, but between age 6 to 18 months, their development slows down as their heads no longer grow normally. They do not develop normal speech, and exhibit unusual repetitive hand movements, torso shaking, and unusual patterns of walking. Often there are breathing problems, seizures, rigid muscles, retarded growth, and other problems. Life expectancy is around 40 years.

2) Childhood Disintegrative Disorder (CDD) is an extremely rare disorder affecting mostly males. The child is okay until 42 months or so. Then a dramatic loss of language and social skills occurs. The child may lose bladder and bowel control and develop seizures. Usually these children have very low intelligence. CDD is the easiest for doctors to diagnose.

3) Autism. Doctors often call it classic autism, Early Infantile Autism, or Kanner’s Autism. Publishing in the 1940’s, Dr. Leo Kanner was among the first to describe the condition. Before his work, doctors labeled such children as mentally retarded or emotionally disturbed. Autistic people show symptoms in varying degrees. About 75% have IQs below 70. There are usually problems with sensory integration, which means they have trouble processing information through their senses of touch, smell, sight, taste and touch.

4) Asperger Syndrome, now considered high-functioning autism on the spectrum. “Aspies” often are not diagnosed until after age three, because they usually have no problem acquiring and using language. The most distinct symptom is an intense interest in a narrow subject. Some children with Asperger Syndrome can recite whole movies or the complete texts of books; others memorize endless facts about some obscure subject. They may show signs of autism such as the need for strict routines, inability to master social interactions and communication, and odd repetitive behaviors. They often have problems controlling their voices.

5) Pervasive Developmental Disorder/Not Otherwise Specified – With PPD/NOS, symptoms don’t fall neatly into place. A diagnostician cannot absolutely declare that the person has autism or a categorized PDD because some of the symptoms are missing, in the wrong combination, or very mild. This is a “catch-all” diagnosis or an umbrella term sometimes used until a more precise diagnosis can be made.



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Mental Health in the United States: Parental Report of Diagnosed Autism in Children Aged 4–17 Years, The Center for Disease Control, posted May 6, 2006 at

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The team behind Your Little Professor is dedicated to providing factual information for parents and caretakers of adolescents on the Autism Spectrum Disorder. We believe in connecting families to the necessary resources in order to help individuals on the spectrum succeed in day-to-day life.