Developmental Disorders
Chapter 13
Pervasive Developmental Disorders: An
Overview
 Nature of Pervasive Developmental Disorders
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Problems occur in language, socialization, and cognition
Pervasive – Means the problems span the person’s entire
life
 Examples of Pervasive Developmental Disorders
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Autistic disorder
Asperger’s syndrome
 Treatment of Autism and other PDD’s focuses upon:
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Acquisition of language skills
Improving quality of social interactions
Acquiring greatest possible functional skills
The Nature of Autistic Disorder: An Overview
 Autism

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Significant impairment in social interactions and
communication
Restricted patterns of behavior, interest, and activities
 Three Central DSM-IV and DSM-IV-TR Features of
Autism
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Problems in socialization and social function
Problems in communication – 50% never acquire useful
speech
Restricted patterns of behavior, interests, and activities
Autistic Disorder: Facts and Statistics
 Prevalence and Features of Autism

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Rare condition – Affecting 2 to 20 persons for every 10,000
people; but prevalence is increasing considerably
Autism occurs worldwide
Symptoms develop before 36 months of age
 Autism and Intellectual Functioning

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50% have IQs in the severe-to-profound range of mental
retardation
25% test in the mild-to-moderate IQ range (i.e., IQ of 50 to
70)
Remaining people display abilities in the borderline-toaverage IQ range
Better language skills and IQ test performance predict
better lifetime prognosis
Increasing Prevalence?
 1966 epidemiological study
 4-5/10,000 (.05%)
(Lotter, 1966)
 2002 review of recent studies
 60 per 10,000 autism spectrum disorders (.6%)
 8 to 30 per 10,000 for autistic disorder (.3%)
 Probably reasons for increase
 Identification of children with higher and lower
intelligence
 Broadening and refining of criteria
 General awareness of the disorder
 Diagnosing disorder in children with other difficulties
Asperger’s Disorder: Part of the Autistic
Spectrum
 The Nature of Asperger’s Disorder


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Such persons show significant social impairments
Restricted and repetitive stereotyped behaviors
May be clumsy, and are often quite verbal (i.e., pedantic or
overly formal speech)
Do not show severe delays in language and other cognitive
skills
 Prevalence of Asperger’s Disorder


Often under diagnosed
Affects about 1 to 36 persons per 10,000 people
CAUSES OF AUTISM-SPECTRUM DISORDERS
 Significant genetic component

Families with 1 autistic child have 3-5% risk of having a
second child with autism (rate in general pop. Is .02-.05%)
 Possible/probably neurological dysfunction
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High rate of MR, clumsiness, abnormal posture or gait
Abnormally small cerebellum
 No evidence for psychosocial causes

Poor parenting does not lead to autism or related disorders
(no “refrigerator mothers”)
TREATMENT
 Specialized behavioral techniques using shaping, discrimination
training, reinforcement to teach small steps
 Communication – speech, sign language, use of picture board
 Socialization – eye contact, some limited social behavior; does
not usually result in “normal” relationships (e.g., friends)
 Intensive, early intervention shows significant and in some
cases, dramatic treatment
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
20-40 hrs/wk, beginning before age 6, 2+ years
This is the most important and best treatment for the disorder
 Support for family
Mental Retardation (MR): An Overview
 Nature of Mental Retardation
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Below-average intellectual and adaptive functioning
Range of impairment varies greatly across persons
 Mental Retardation and the DSM-IV and DSM-IV-TR
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Significantly sub-average intellectual functioning (IQ
below 70)
Concurrent deficits or impairments in two or more areas of
adaptive functioning
MR must be evident before the person is 18 years of age
DSM-IV and DSM-IV-TR Levels of Mental
Retardation (MR)
 Mild MR (85%)

Includes persons with an IQ score between 50 or 55
and 70
 Moderate MR (10%)

Includes persons in the IQ range of 35-40 to 50-55
 Severe MR (3-4%)
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Includes people with IQs ranging from 20-25 up to 35-40
 Profound MR (1-2%)

Includes people with IQ scores below 20-25
Other Classification Systems for Mental
Retardation (MR)
 American Association of Mental Retardation (AAMR)
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Defines MR based on levels of assistance required
Examples of levels include intermittent, limited, extensive,
or pervasive assistance
 Classification of MR in Educational Systems
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Educable mental retardation (i.e., IQ of 50 to
approximately 70-75)
Trainable mental retardation (i.e., IQ of 30 to 50)
Severe mental retardation (i.e., IQ below 30)
 Implications of Different MR Classification Systems
Mental Retardation (MR): Some Facts and
Statistics
 Prevalence
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About 1% to 3% of the general population
90% of MR persons are labeled with mild mental retardation
 Gender Differences

MR occurs more often in males, male-to-female ratio of
about 6:1
 Course of MR
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Tends to be chronic, but prognosis varies greatly from
person to person
BIOLOGICAL CAUSES
 Genetic (only about 30% cases of MR)
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Tuberous sclerosis (rare, but 60% have MR); PKU (restricted
diet till age 7 since unable to break down phenylalanine);
Lesch-Nyhan syndrome
Chromosomal abnormalities
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Down Syndrome – trisomy 21 (extra 21st chromosome)
Fragile X syndrome
PSYCHOLOGICAL & SOCIAL CAUSES
 Cultural-familial retardation (70% cases of MR) –
mild to moderate MR
 combination of biological and psychological factors?

abuse, neglect, social deprivation
TREATMENT OF MR
 Goal of maximizing functioning
 Select reasonable goals for areas of functioning
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Self-care (dressing, feeding self)
Communication
Social skills
Tasks of daily living (transportation, buying groceries)
Cognitive skills developed as appropriate (read, write,
make change)
 Use behavioral techniques to teach skills, shaping,
repeated trials, reinforcement
 Individuals with MR have higher rate of other
psychological disorders (depression, psychosis)