About Autism

Autism is one type of Pervasive Developmental Disorder (PDD). The other types are Asperger’s syndrome, Rett’s syndrome, Childhood Disintegrative Disorder, and PDD-Not Otherwise Specified (NOS).

These disorders are all similar in that they are typified by deficiencies in language skills and social skills. In addition, individuals with PDDs may demonstrate repetitive behaviors or movements and exhibit restricted interests. Currently autism is the most common of these diagnoses. Often the specific cause of PDD for an individual cannot be identified. However, continuing research at numerous national centers is beginning to provide clues to the causes. It appears that genetics plays a key role in the development of autism, though in some cases an environmental trigger is necessary for the genetic susceptibility to manifest. Much research shows that autism is a brain-based disorder in which the structures and connections in the brain are altered, thus leading to the behaviors associated with PDDs.           

Diagnosis
Diagnosis of a PDD is most commonly based on the criteria outlined by the American Psychological Association (APA) in their Diagnostic & Statistical Manual (DSM). The diagnosis is made by a professional based on an extensive health history, results from standardized tests, behavioral observations, and in some cases genetic screening. The main areas of interest to diagnosticians are social skills, communication skills, and presence of stereotyped behaviors. If all three areas are involved, then a diagnosis of autism is common. If deficiencies are noted in the areas of social skills and stereotyped behaviors but not communication, then a diagnosis of Asperger’s syndrome may be made. A diagnosis of PDD-NOS is typically made if all three areas of development are disrupted but not to a sufficient degree to warrant a diagnosis of autism. Rett syndrome is diagnosed when all three areas are involved and there is evidence of a specific loss of genetic information. Rett syndrome occurs only in females.

DSM Diagnostic Criteria for Autism
An autism diagnosis will be made if the individual exhibits at least 6 of the following symptoms, with at least 2 in the social skills realm and at least one in each of the other two domains. There also must be evidence that the developmental issues began prior to the age of 3 years.

A) Social Interaction (at least 2 must be present):

(1) marked impairment in the use of multiple nonverbal behaviors, such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction

(2) failure to develop peer relationships appropriate to developmental level

(3) a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest)

(4) lack of social or emotional reciprocity

(B) Communication (at least 1 must be present):

(1) delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime)

(2) in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others

(3) stereotyped and repetitive use of language or idiosyncratic language

(4) lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level

(C) Patterns of Behavior, Interests, and Activities (at least 1 must be present)

(1) encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus

(2) apparently inflexible adherence to specific, nonfunctional routines or rituals

(3) stereotyped and repetitive motor mannerisms (e.g., hand or finger flapping or twisting or complex whole-body movements)

(4) persistent preoccupation with parts of objects

DSM Diagnostic Criteria for Asperger's Syndrome
An Asperger’s syndrome diagnosis will be made if the individual meets the following criteria involving deficits in social interaction with the presence of stereotyped interests and/or behaviors. This syndrome is distinct from autism in that language skills are preserved. The Asperger’s diagnostic category may no longer be recognized as distinct from autism once the new DSM definition rules are announced in 2012.

(A) Social Interaction (at least 2 must be present)

(1) marked impairment in the use of multiple nonverbal behaviors, such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction

(2) failure to develop peer relationships appropriate to developmental level

(3) a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest)

(4) lack of social or emotional reciprocity

(B) Patterns of Behavior, Interests, and Activities (at least 1 must be present)

(1) encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus

(2) apparently inflexible adherence to specific, nonfunctional routines or rituals

(3) stereotyped and repetitive motor mannerisms (e.g., hand or finger flapping or twisting or complex whole-body movements)

(4) persistent preoccupation with parts of objects

(C) The disturbance causes clinically significant impairment in social, occupational, or other important areas of functioning.

(D) There is no clinically significant general delay in language (e.g., single words used by age 2 years, communicative phrases used by age 3 years).

(E) There is no clinically significant delay in cognitive development or in the development of age-appropriate self-help skills, adaptive behavior (other than in social interaction), and curiosity about the environment in childhood.

(F) Criteria are not met for another specific pervasive developmental disorder or schizophrenia.

DSM Criteria for Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS)
This category 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, schizophrenia, schizotypal personality disorder, or avoidant personality disorder. For example, this category includes "atypical autism" --presentations that do not meet the criteria for autistic disorder because of late age of onset, atypical symptomatology, or subthreshold symptomatology, or all of these.

Standard Assessment Instruments for PDD
Below is a partial listing of common screening tests for autism and pervasive developmental disorders. Because the screening tests vary in their format and structure (e.g., observational, parent/guardian/teachersurvey), it is common for more than one to be used for diagnosing a single child.

Modified Checklist for Autism in Toddlers (M-CHAT)
The M-CHAT is a short questionnaire that is filled out by the parents and a physician at the 18-month developmental check-up. The M-CHAT consists of two sections: questions asked to the parents, and items observed by the physician. The key items look at behaviors which, if absent at 18 months, put a child at risk for a social-communication disorder. These behaviors are (a) joint attention, including pointing to show and gaze-monitoring (e.g., looking to where a parent is pointing) and (b) pretend play (e.g., pretending to pour tea from a toy teapot).

Autism Diagnostic Observation Schedule - Generic (ADOS-G)
The ADOS-G is a semi-structured assessment of communication, social interaction and play or imaginative use of materials for individuals suspected of having autism or other pervasive developmental disorders (PDDs). Only a trained and experienced clinician should administer this test to your child. It consists of standard activities that allow the examiner to observe the occurrence or non-occurrence of behaviors that have been identified as important to the diagnosis of autism and other pervasive developmental disorders. Structured activities and materials, and less structured interactions, provide standard contexts in which social, communicative and other behaviors relevant to pervasive developmental disorders are observed.

Autism Diagnostic Interview-Revised (ADI-R)
The ADI-R is a standardized, semi-structured clinical interview for assessing autism children and adults. The interview contains 93 items and focuses on behaviors in three content areas or domains: quality of social interaction (e.g., emotional sharing, offering and seeking comfort, social smiling and responding to other children); communication and language (e.g., stereotyped utterances, pronoun reversal, social usage of language); and repetitive, restricted and stereotyped interests and behavior (e.g., unusual preoccupations, hand and finger mannerisms, unusual sensory interests).