Developmental Disorders
A developmental disorder is a problem that
interrupts the normal sequence of development by which people mature and
learn skills. Developmental disorders include most of the well-known
syndromes that include intellectual disabiliy, such as Down syndrome.
Other developmental disorders affect only one isolated part of the
intellect. An example is dyslexia (classified as a communication
disorder in DSM-IV). Still other developmental disorders are complex
syndromes with widely varying effects, such as autism. What all developmental disorders have in common is that they represent unusual limits or blockades on development.
What are developmental disorders?
DSM-IV covers developmental disorders under "Disorders
Usually First Diagnosed in Infancy or Childhood." On coming pages we
depart from strict adherence to the DSM-IV scheme in two ways: by using
the term developmental disorders (which was used as a category in
DSM-III but not in DSM-IV) and by taking a look at Down syndrome (which
is almost ignored in DSM-IV).
Down Syndrome
Down Syndrome is the most
common form of mental retardation. It is caused by a common genetic
problem that can be diagnosed while a baby is still in the womb.
What is Down Syndrome? What are some physical symptoms of Down Syndrome?
Physical symptoms of Down Syndrome children may include the following:
—short, wide, or broad body parts: e.g. a short thick
neck; a large tongue which may protrude involuntarily; small, broad,
flat hands and feet; lack of overall body height
—a distinctive facial appearance, including small
teeth; underdeveloped bones of the nose; small, round, bulging or
slanted-looking eyes with a fold of skin near the bridge of the nose
—a variety of medical problems, not inevitable, but
more common among Down Syndrome children: heart disorders, eye problems,
a rare type of leukemia, missing or misaligned teeth, and metabolic
irregularities.
Autism
Autism is a problem that affects certain children from
birth onward. It is far less common than Down Syndrome but receives a
lot of attention because of its intriguing characteristics, and it has
become more frequently diagnosed in recent years-a fact which is
controversial in itself. Nobody is sure whether some environmental cause
of autism is becoming more common or whether people are simply more
aware of autism now, compared to a few decades ago.
DSM-IV categorizes autism as a Pervasive Developmental Disorder
because it tends to influence all aspects of a child's life. Twin
studies suggest autism is a genetic disorder, although the nature of the
disorder has not been pinned down as it has in the case of Down
Syndrome (Ritvo, 1985).
What is autism?
The autistic baby fails to respond to cuddling and seems
cut off from other people. He or she does not progress as quickly as
other children. Speech onset is delayed, if the child learns to speak at
all. . In the days before newborns were screened for hearing problems,
parents would often bring an autistic child to a doctor because they
suspected that the child is deaf. It would turn out the child was not
deaf but was ignoring people. To this day, one of the informal ways to
screen for autism in a child younger than one year of age is to call the
baby's name and see if it turns toward the voice. Normal babies will do
this around eight or nine months of age. Autistic babies will not do
it.
What are ingredients of Kanner's description?
Social aloneness is one part of the autistic
syndrome. There are many other characteristics that autistic children
have sometimes but not always. Together they form a distinctive
syndrome. Leo Kanner, sometimes called the father of child psychiatry,
mentioned many of these characteristics in his original description of
the syndrome in 1947:
—As a baby, the autistic child fails to assume the normal anticipatory posture prior to being picked up.
—The children often show an excellent rote memory for "poems, songs, lists of presidents and the like."
—When and if the child learns to speak, the first
sentences tend to be "parrot-like repetitions of word combinations,"
sometimes echoed immediately and sometimes stored for long periods and
"uttered at a later date."
—Autistic children typically have difficulty learning
to use pronouns correctly; the child speaks of himself as "you" and of
another person as "I," failing to switch the words to suit the context
of who is speaking.
—The child may show an "obsessive desire for sameness" and become enraged when a piece of furniture is moved.
—The child may show a fascination with spinning objects and regularly occurring environmental events.
—Autistic children typically show no evidence of abnormality in the EEG and no other signs of brain damage.
—Autistic children are often strikingly good looking, unlike many retarded and brain-damaged children.
—Autistic children often excel at a particular,
limited skill, such as finding prime numbers, memorizing calendar dates,
or composing music.
Learning disorders
A learning disorder is a selective impairment of
performance. A person with a learning disorder may do perfectly well in
all areas of school except one. In that one area (or a set of related
areas) the student cannot seem to learn despite hard work and ample
opportunities. Typically a learning disorder involves some distinct type
of information processing such as memorization, mathematics, motor
skills, foreign language learning, or reading. An exception is the most
commonly diagnosed learning disorder, ADD (attention deficit disorder)
and the common variation called ADHD (attention deficit/hyperactivity
disorder).
ADD and ADHD
A child with ADHD typically shows these symptoms:
inattention ("often fails to finish things he or she starts, often
doesn't seem to listen, easily distracted, has difficulty concentrating
on schoolwork or other tasks"); impulsivity ("often acts before
thinking, shifts excessively from one task to another, has difficulty
awaiting turn in games or group situations"); and hyperactivity (fidgets
excessively, has difficulty staying seated, moves about excessively
during sleep, is always "on the go" or acts as if "driven by a motor").
Dyslexia (reading disorder)
The most commonly diagnosed learning disorder in school settings is dyslexia. Dyslexia is a learning disorder involving reading ability. In fact, DSM-IV does not use the term dyslexia. It simply labels the syndrome "Reading Disorder."
What is dyslexia, and what is it called in DSM-IV?
A reading disorder may leave other intellectual
abilities untouched. The dyslexic person may be smart in all the normal
ways, except for this one problem: the dyslexic person has a hard time
extracting meaning from the written word.
Several different types of dyslexia can be identified. About two-thirds of dyslexics are
verbal dyslexics
whose specific problem is sound of a written word and hearing it like a
normal word. This problem slows them in reading and prevents them from
extracting the meaning (a problem illustrated by a
demonstration in Chapter 7).
What are two different types of dyslexia?
The remaining third of dyslexics are spatial dyslexics
who have trouble discriminating the spatial relationships of letters in
a word. These individuals tend to invert letters, turning them
backwards. Their reading is also disrupted.
