Autism Spectrum Disorders

Autism spectrum disorders (ASDs) are characterized by varying degrees of impairment in communication skills, social interactions, and restricted and repetitive patterns of behavior. The disorders range from a severe form (called autistic disorder) to a milder form (Asperger syndrome). Often, ASDs can be reliably detected by the age of 3, and in some cases as early as 18 months.

What Are Autism Spectrum Disorders?

Not until the middle of the twentieth century was there a name for a disorder that now appears to affect an estimated one of every five hundred children, a disorder that causes disruption in families and unfulfilled lives for many children.
 
In 1943, Dr. Leo Kanner of the Johns Hopkins Hospital studied a group of 11 children and introduced the label "early infantile autism" into the English language. At the same time a German scientist, Dr. Hans Asperger, described a milder form of the disorder that became known as Asperger syndrome.
 
Thus these two disorders were described and are today listed in the Diagnostic and Statistical Manual of Mental Disorders [DSM-IV-TR (fourth edition, text revision)] as two of the five pervasive developmental disorders (PDD), more often referred to today as autism spectrum disorders.
 
All these disorders are characterized by varying degrees of impairment in communication skills, social interactions, and restricted, repetitive, and stereotyped patterns of behavior.
 

Types

The pervasive developmental disorders, or autism spectrum disorders, range from a severe form, called autistic disorder, to a milder form known as Asperger syndrome.
 
If a child has symptoms of either of these disorders, but does not meet the specific criteria for either, the diagnosis is called pervasive developmental disorder not otherwise specified (PDD-NOS).
 
Other rare, very severe disorders that are included in the autism spectrum disorders are Rett syndrome and childhood disintegrative disorder.
 

Diagnosing Autism Spectrum Disorders

The autism spectrum disorders can often be reliably detected by the age of 3 years, and in some cases as early as 18 months. Studies suggest that many children eventually may be accurately identified by the age of 1 year or even younger. The appearance of any of the warning signs of autism spectrum disorder is reason to have a child evaluated by a professional specializing in these disorders.
 
Pediatricians, family physicians, daycare providers, teachers, and parents may initially dismiss signs of autism spectrum disorders, optimistically thinking the child is just a little slow and will "catch up." Although early intervention has a dramatic impact on reducing symptoms and increasing a child's ability to grow and learn new skills, it is estimated that only 50 percent of children are diagnosed before kindergarten.
 
(Click Diagnosing Autism Spectrum Disorders for more information.)
 

What Are the Symptoms?

Parents are usually the first to notice unusual behaviors in their child. In some cases, the baby seemed "different" from birth, unresponsive to people, or focusing intently on one item for long periods of time. The first signs of an autism spectrum disorder can also appear in children who seem to have been developing normally. When an engaging, babbling toddler suddenly becomes silent, withdrawn, self-abusive, or indifferent to social overtures, something is wrong. Research has shown that parents are usually correct about noticing developmental problems, although they may not realize the specific nature or degree of the problem.
 
All children with autism spectrum disorders:
 
  • Demonstrate deficits in social interaction
  • Have difficulty with verbal and nonverbal communication
  • Display repetitive behaviors or narrow, obsessive interests.
     
In addition, they will often have unusual responses to sensory experiences, such as certain sounds or the way objects look.
 
Each of these symptoms runs the gamut from mild to severe. They will present in each individual child differently. For instance, a child may have little trouble learning to read but exhibit extremely poor social interaction. Each child will display communication, social, and behavioral patterns that are individual but fit into the overall diagnosis of ASD.
 
(To learn more about the specific symptoms, click Autism Spectrum Disorder Symptoms.)
 

Treatment

The earlier the disorder is diagnosed, the sooner the child can be helped through treatment interventions.
 
(Click Autism Spectrum Disorder Treatment for a detailed description of the different treatments.)
 

Statistics for Autism Spectrum Disorders

Prevalence estimates range from 2 to 6 per 1,000 children. This wide range of prevalence points to a need for earlier and more accurate ASD screening.
 
(To learn more, click Autism Spectrum Disorder Statistics.)
 
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD
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