SPECIFIC
DEVELOPMENTAL DISORDERS
This subclass is for disorders that are
characterized by inadequate development of
specific academic, language, speech, and
motor skills and that are not due to
demonstrable physical or neuralgic disorders,
a Pervasive Developmental Disorder, Mental
Retardation, or deficient educational
opportunities. For example, a marked delay in
language development in an otherwise normal
child would be classified as a Specific
Developmental Disorder, but a delay in
language development in a child with a
Pervasive Developmental Disorder would be
attributed to the Pervasive Developmental
Disorder and therefore would not be
classified as a Specific Developmental
Disorder. Similarly, a marked delay in
learning to read experienced by an otherwise
normal child with adequate educational
opportunities would be classified as a
Specific Developmental Disorder, whereas a
delay in learning to read commensurate with
general delays in development would be
classified as Mental Retardation, not as a
Specific Developmental Disorder.
The diagnosis of an Academic Skills
Disorder (Developmental Arithmetic,
Expressive Writing, and Reading Disorders) is
made with the aid of standardized,
individually administered tests that measure
both the level of development of the impaired
skill and the person's intellectual capacity.
In diagnosing Developmental Expressive and
Receptive Language Disorders, it is necessary
to compare scores obtained from standardized
measures of expressive or receptive language
with scores obtained from standardized
measures of nonverbal intellectual capacity.
It should be noted that a diagnosis of Mental
Retardation in a child does not preclude the
additional diagnosis of a Specific
Developmental Disorder. For example, a child
with an IQ of 60 should, with adequate
schooling, be able to read simple materials
If the child's ability to read is markedly
below what would be expected given an IQ of
60, both Mental Retardation and Developmental
Reading Disorder should be diagnosed.
When a child has more than one Specific
Developmental Disorder, all should be
diagnosed. A Specific Developmental Disorder
that appears to be caused by another Specific
Developmental Disorder should be separately
diagnosed. For example, a child with
Developmental Receptive Language Disorder may
show deficits in the development of
arithmetic skills that are apparently related
to the language disorder (i.e., a lack of
understanding of numerical terms). In this
example, the child would he diagnosed as
having both Developmental Receptive Language
Disorder and Developmental Arithmetic
Disorder.
The inclusion of these categories in a
classification of "mental
disorders" is controversial, since many
of the children with these disorders have no
other signs of psycho-pathology. Further, the
detection and treatment of many of these
disorders usually take place within schools
rather than the mental health system.
Although many of the clinical features seen
in Specific Developmental Disorders represent
functional levels that are normal for very
young children (e.g., inability to do
arithmetic), there is no implication that
children with these disorders will
"catch up" over time. In fact,
children with more severe forms of these
disorders frequently continue to show signs
of the disturbance in adolescence and
adulthood; and the relevant diagnosis should
be noted when an adult still has clinically
significant signs of the disorder.
Impairment. All of the
Specific Developmental Disorders are
associated with impairment in academic
functioning in children who are in school;
impairment is most marked when language is
affected. If the child is not in school,
there is, by definition, impairment in
activities of daily living.
Predisposing factors.
There is some evidence that prenatal injury
of various kinds predisposes to the
development of Specific Developmental
Disorders.
Complications. A common
complication of Developmental Expressive or
Receptive Language Disorder Is an Academic
Skills Disorder. A common complication of
Academic Skills Disorders is Conduct
Disorder.
Sex ratio. No information
is available for Developmental Arithmetic and
Developmental Coordination Disorders. The
other Specific Developmental Disorders are
from two to four times more common in males
than in females.
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