Autism Health Article

Definition

Autism is a severely incapacitating developmental disorder of brain function characterized by three major types of symptoms: impaired social interaction, problems with verbal and nonverbal communication, and unusual or severely limited activities and interests.

Description

Autism is a complex developmental disability with symptoms that typically appear during the first three years of childhood and continue throughout life. It is the most severe disorder within a group of developmental disorders called autism spectrum disorders (ASDs) or pervasive developmental disorders (PDDs) that cover a wide range of behaviors and symptoms, all related to a lesser or greater extent to impaired social and communication skills.

In its most severe form, autism may include extreme self-injurious, repetitive, highly unusual, and aggressive behaviors.

Demographics

According to the Center for Disease Control and Prevention, PDDs were estimated to occur in two to six per 1,000 births in 2003 with autism being the most common PDD, affecting an estimated one in 250 births. As of 2004, as many as 1.5 million Americans are were believed to have some form of autism. The disorder is four times more prevalent in boys than girls and is not associated with any specific racial or ethnic background. Family income, lifestyle, and educational levels also do not affect the chance of the disorder's occurrence.

The Autism Society of America (ASA) warns that autism is on the rise. Based on statistics from the U.S. Department of Education and other governmental agencies, the ASA estimates that the disorder is growing at a rate of 10 to 17 percent per year, which could lead to 4 million Americans being affected by autism between 2005 and 2015.

Causes and symptoms

While understanding of autism grew tremendously since it was first described by Leo Kanner in 1943, no known single cause for autism as of 2004 was yet identified, although research has shown that it results from specific abnormalities in brain structure or function. For example, brain scans show that the shape and structure of the brain in autistic children are different from those of non-autistic children. Researchers investigated several theories and established a firm link between heredity, genetics, and medical problems, while also establishing that no known psychological factors in the development of the child have been shown to cause autism.

The genetic link is supported by observations showing that, in many families, there seems to be a pattern of autism or ASDs. While no one gene was identified as causing autism as of 2004, researchers are searching for irregular segments of genetic code that autistic children may have inherited.

Autism has also been shown to occur more frequently among individuals who have certain medical> conditions, including> fragile X syndrome, tuberous sclerosis, congenital rubella syndrome, and untreated phenylketonuria.

Toxins and pollution in the environment have also been associated with autism. The Center for the Study of Autism and other agencies documented a high prevalence of autism in certain communities, for example, in the small town of Leomenster, Massachusetts, and in Brick Township, New Jersey, and attempted to uncover the reason.

The symptoms of autism occur in a wide variety of combinations, from mild to severe and are caused by physical disorders of the brain. According to the ASA, they may include any combination of the following in varying degrees of severity:

• insistence on sameness; resistance to change
• difficulty in expressing needs; using gestures or pointing instead of words
• repeating words or sentences instead of using normal, responsive language (echolalia)
• laughing, crying, showing distress for reasons not apparent to others
• aloof behavior, seeking solitude
• tantrums
• refusal to cuddle or be cuddled
• little or no eye contact
• unresponsiveness to normal teaching methods
• sustained odd play
• inappropriate attachments to objects
• apparent over-sensitivity or under-sensitivity to pain
• no fear of danger
• uneven gross/fine motor skills
• not responsive to verbal cues; acts as if deaf although hearing tests in normal range

When to call the doctor

The characteristic behaviors of autism may or may not be apparent in infancy (18 to 24 months) but usually become obvious during early childhood (two to six years).

The National Institute of Child Health and Human Development (NICHD) lists the five following behaviors as signals that medical evaluation is needed:

• does not babble or coo by 12 months
• does not gesture (point, wave, grasp) by 12 months
• does not say single words by 16 months
• does not say two-word phrases on his or her own by 24 months
• loss of any language or social skills at any age

The presence of any of these five behaviors does not mean that a child has autism, but because the characteristics of the disorder vary so much, a child should be evaluated by a multidisciplinary team that may include a neurologist, psychologist, developmental pediatrician, speech/language therapist, learning consultant, or other professionals knowledgeable about autism.