Learn about Autism

Educational Definition (Individuals with Disabilities Education Act, or IDEA 2004)

Autism is a developmental disability that significantly affects verbal and nonverbal communication and social interaction. It is generally evident before age 3 and adversely affects a child's educational performance. Other characteristics often associated with autism include engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences.

Autism does not apply if a child's educational performance is adversely affected primarily because the child has an emotional disturbance.

A child who manifests the characteristics of autism after age 3 may be identified as having autism.

What are Autism Spectrum Disorders (ASD)?

Autism Spectrum Disorders include autism and related disorders such as Asperger Syndrome, Rett Syndrome, childhood disintegrative disorder, and pervasive developmental disorder-not otherwise specified (PDD-NOS).

Pervasive Developmental Disorders (PDD)

The term PDD is widely used by professionals to refer to children with autism and related disorders. The DSM-IV-TR includes autism and other developmental disabilities such as Rett Syndrome, Childhood Disintegrative Disorder, PDD-NOS, and Asperger Syndrome under the PDD category. Therefore, PDD is not a specific diagnosis but a broad term that includes various conditions.

Autism

Autism is one of the pervasive developmental disorders included in the DSM-IV-TR criteria. It refers to the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activities and interests.

Asperger Syndrome/High-Functioning Autism

The main characteristic of Asperger Syndrome is impairment of social interaction. Asperger Syndrome first appeared in the DSM-IV in 1994, 50 years after the Austrian physician Hans Asperger published his first paper on 'autistic psychopathy' in 1944.

The relationship between Asperger Syndrome and high-functioning autism is still controversial. Even though high-functioning autism is not an official diagnosis, many professionals still use the terms Asperger Syndrome and high-functioning autism interchangeably because of a lack of information differentiating the two.

The DSM-IV-TR diagnostic criteria for Asperger Syndrome include qualitative impairment in social interaction, and restricted repetitive and stereotyped patterns of behavior, interests, and activities. There is no specific diagnostic criteria for high-functioning autism.

Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS)

According to the DSM-IV-TR, this category includes atypical autism and should be used when there is a severe and pervasive impairment in the development of reciprocal social interaction or verbal and nonverbal communication skills, or when stereotyped behavior, interests, and activities are present, but the criteria are not met for a specific pervasive developmental disorder such as autism, Asperger Syndrome, schizophrenia, schizotypical personality disorder, or avoidant personality disorder. For example, this category includes individuals who do not meet the criteria for Autistic Disorder because of late age of onset.

Change in the Definition of Autism in the DSM

Among the many uses of the Diagnostic and Statistical Manual of Mental Disorders (DSM) is to determine whether an individual has autism. Typically used in medical and clinical settings, this document is being revised. In 2013, the DSM-5 will be published with a new definition of autism. The changes include:

	DSM IV	DSM V
Category Name	Pervasive developmental disorders	Autism spectrum disorders
Domains	Social interaction Communication Restricted repetitive	Social communication Fixated interests and repetitive behaviors
Age	Onset prior to age 3	Must be present in early childhood (but may not become fully apparent until social demands exceed skills)
Differentiation	Autistic Disorder, Asperger's Disorder, Rett's Disorder, Childhood Disintegrative Disorder, Pervasive Developmental Disorder - Not Otherwise Specified	Three levels: requiring very substantial support (3), requiring substantial support (2), requiring support (1)
"Functioning"	Delays or abnormal functioning	Symptoms impact and impair everyday functioning
Impact of the New Diagnostic Criteria	No one knows. A member of the DSM committee conducted a study and found no negative impact. Another professional, not on the committee, conducted a study and found that a substantial percent of those with autism may not meet the DSM-V criteria.

Prevalence of ASD

The prevalence of ASD is increasing.  Based on parent reports, the prevalence of diagnosed ASD in 2011-2012 was estimated to be 2.00% for children aged 6-17, with an estimate of 1 in 50. School-aged boys were more than 4 times as likely as school-aged girls to have ASD. The incidence of autism is consistent around the globe. Autism knows no racial, ethnic, or social boundaries, and family income, lifestyle, and educational levels do not affect the chance of the occurrence of autism.