Pervasive Developmental Disorders or Autism Spectrum Disorders (ASD)
are a group of developmental disabilities, which according to recent
estimates, affect as many as 1-2 out of every 500 people. The
Pervasive Developmental Disorders are also known as the autism-spectrum
disorders, and they include Autistic Disorder, Pervasive Developmental
Disorder-Not Otherwise Specified (PDD-NOS), Asperger’s Disorder, Rett’s
Disorder, and Childhood Disintegrative Disorder. They affect up
to 4-5 times as many boys as girls, occur in all cultures, and are present
among all socioeconomic classes. They usually become noticeable
between the ages of 1 and 3 years, and affect the way in which social
behavior, communication (verbal and nonverbal communication), and attention/interests
develop. There is a wide spectrum of impairment associated with
the Pervasive Developmental Disorders, which can range from mild to
severe. The PDDs do not describe a delay in development, but rather
a difference or deviation in development in these three areas.
Developmental Disorders are neurologically-based, medical disorders
that are not caused by errors in parenting, a specific environmental
toxin, poor prenatal care, etc. In a percentage of cases, there
may be a genetic cause. Although scientists are making strides
in identifying their cause(s), right now, there does not appear to be
one specific cause for all cases. A physician or psychologist
may diagnose one of these conditions using a medical model (following
the criteria set forth in the Diagnostic and Statistical Manual-Fourth
Edition, DSM-IV). Alternatively, an education team may assign
an educational eligibility (autism), based on a child's special needs
for educational modifications. At the present time, there is no
medical test that indicates an autism spectrum disorder; however, routine
medical screenings (metabolic, genetic, and Fragile X) are recommended
to rule out the presence of another identifiable condition. In
either case, the diagnosis of a PDD is based on behavioral observations
and clinical experience.
Pervasive Developmental Disorder is a general category used to describe a pattern of behavioral differences (which may include deviations, excesses, or difficulties) in the areas of social relating, communication, and attention/interest. Children who demonstrate a number of characteristics or symptoms in these three areas, and whose problems are not better explained by other disorders, may receive a diagnosis of PDD. This diagnosis may also be applied if the child exhibits a variety of symptoms associated with Autism, but in an unusual pattern. It should be stressed that this is still a relatively new label, dating back only 15 years, so that some professionals may not be familiar with its correct use. In some cases, it has been incorrectly used synonymously with "significant developmental delay” or “general delay" or "developmental delay." Both Autism and PDD-NOS can occur in conjunction with a wide spectrum of intellectual ability. The defining feature must be a qualitative difference in social and language development for these diagnoses.
and PDD-NOS are subtypes of the Pervasive Developmental Disorders.
It is common for a person to be given the general diagnosis of PDD,
which indicates an autism spectrum disorder without clarifying the exact
form of PDD. The differential diagnosis of the PDDs is based on
a particular pattern or clustering of symptoms, and specific criteria
on the number of symptoms that are observed. In both disorders,
there is a higher likelihood of developing seizures than in individuals
Primarily by the pattern and degree or number of characteristics observed or reported. However, there are difficulties associated with this differential diagnosis, and it often takes a clinician with extensive experience with both disorders to make the call.
may occur when a child's developmental level is quite low, so that assessing
the areas of concern would be quite difficult at a similar age equivalent.
A second problem occurs with children who are toddlers and young preschool-age
children. Many of the behaviors that are considered crucial for
diagnosis are still very variable in typically developing young children
in this age range. Some children may receive a diagnosis of PDD-NOS
as a toddler because they did not have any communicative behavior; later
they may qualify for a diagnosis of autism as their communication develops
and it becomes more evident that a qualitative difference exists in
that area. For parents and educators, the important thing to focus
on is not the specific label a child receives, but what can be done
to help the child develop skills in the areas of concern.
Disorder was only added as a subtype of the PDDs in the DSM-IV in 1994,
so its characteristics are still under a great deal of study.
Similar to distinguishing Autism from PDD-NOS, there are specific criteria
that distinguish Autism and Asperger’s. Some of the key differences
between Autism and Asperger’s are that the individual could not have
had a clinically significant language delay (although unusual patterns
of communication and impaired nonverbal communication is generally present),
and the individual must function within average to above average intellectual
(cognitive) levels. There is currently much debate between professionals
whether Asperger’s Disorder should really be distinguished from high-functioning
Autism, and clinical experience is often important to determine how
these diagnoses should be applied to a particular individual.
Intellectual impairment (mental retardation) is a term used to describe individuals who follow a slower developmental path than others their age. “Intellectual impairment” is the term generally used by educators and “mental retardation” is the term used in the DSM-IV; however, these terms generally refer to the same types of learning difficulties. People with an intellectual impairment continue to develop skills and abilities as they grow, although they typically progress more slowly than their peer group. Intellectual Impairment is identified by comparing a person's intellectual performance on standardized tests with others in his/her age group, and by looking at how well that individual can function in adaptive skills (self-care, safety knowledge, independent living skills).
Autism and PDD-NOS can be present in people who also have an intellectual impairment; however, they can also be present in individuals who have superior intellectual skills. It varies from individual to individual. However, because communication skills are an integral part of what most people consider intelligence, the problems people with autism show in this area may affect their ability to perform on standardized intelligence tests. Some individuals with Autism may receive a diagnosis of intellectual impairment or mental retardation due to suppressed performance in areas involving verbal expression or understanding, while performing above average in some other areas (such as memory and visual problem-solving). In such cases, the term is not particularly meaningful or predictive of long-term outcome.
When assessing the skills of a child with a PDD, it is important to evaluate the skills that they show on an everyday basis in situations that are meaningful and familiar to them. Evaluation should not only focus on identifying a child’s intellectual level, but should aim to identify the child’s learning characteristics so that meaningful goals can be planned to help the child develop to his or her potential.
Autism/PPD-NOS is a life-long disability, and individuals with Autism live a full lifetime. There are no cures, and even those individuals who proclaim themselves "recovered" continue to have difficulties with subtle social processes. However, with advances in education, early intervention, and research, today individuals with Autism/PDD have a greatly expanded range of outcomes as adults. In the past, the majority of individuals with Autism lived in institutional care as adults. Current trends, based on increased knowledge of how to educate children with Autism and the importance of early education, emphasize building skills and abilities in order to prepare young adults with Autism/PDD to work, to live in the community, and in some cases, to pursue higher education. Outcome appears to depend on both degree of overall impairment and intensity of educational/treatment effort. Prognosis is markedly better for individuals who develop verbal language before the age of 5 years
For most children with Autism, there is no physical reason to preclude learning to use verbal communication. Unless there is a specific physical problem (such as deafness, absence of larynx/pharynx, focal lesion the brain), there is no reason to make such an assumption. It should be noted that speech does not frequently come easily to individuals with Autism, and research suggests that intensive efforts and education are often needed for children with Autism to develop speech. However, given the relationship between speech development and prognosis, aggressively pursuing verbal communication skills is highly recommended for young children with Autism/PDD-NOS.
Individuals with Autism frequently display certain clusters of behavior that distinguish them from individuals who do not have Autism. Diagnosing this syndrome using the DSM-IV involves consideration of the following characteristics.
The child need not show all of these characteristics.
I. Qualitative impairment in reciprocal social interactions:
Behaviors suggesting this area may be affected include:
should I do about my child's Autism/PDD-NOS?