◗ MENTALRETARDATION
The essential feature of mental retardation is below-
average intellectual functioning (IQ less than 70)
accompanied by significant limitations in areas of
adaptive functioning such as communication skills,
self-care, home living, social or interpersonal skills,
use of community resources, self-direction, academic
skills, work, leisure, and health and safety (King,
Hodapp & Dykens, 2000). The degree of retardation
is based on IQ and greatly affects the person’s abil-
ity to function:
- Mild retardation: IQ 50 to 70
- Moderate retardation: IQ 35 to 50
- Severe retardation: IQ 20 to 35
- Profound retardation: IQ less than 20
Causes of mental retardation include heredity
such as Tay-Sachs disease or fragile X chromosome
syndrome; early alterations in embryonic develop-
ment such as trisomy 21 or maternal alcohol intake
that causes fetal alcohol syndrome; pregnancy or
perinatal problems such as fetal malnutrition, hy-
poxia, infections, and trauma; medical conditions of
infancy such as infection or lead poisoning; and envi-
ronmental influences such as deprivation of nurtur-
ing or stimulation.
Some people with mental retardation are passive
and dependent; others are aggressive and impulsive.
Children with mild to moderate mental retardation
usually receive treatment in their homes and commu-
nitiesand make periodic visits to physicians. Those
with severe or profound mental retardation may re-
quire residential placement or day care services.
◗ LEARNINGDISORDERS
A learning disorder is diagnosed when a child’s
achievement in reading, mathematics, or written ex-
pression is below that expected for age, formal edu-
cation, and intelligence. Learning problems interfere
with academic achievement and life activities re-
quiring reading, math, or writing (American Psychi-
atric Association [APA], 2000). Reading and written
expression disorders usually are identified in the
first grade; math disorder may go undetected until
the child reaches fifth grade. About 5% of children in
U.S. public schools are diagnosed with a learning dis-
order. The school dropout rate for students with learn-
ing disorders is 1.5 times higher than the average rate
for all students (APA, 2000).
Low self-esteem and poor social skills are common
in children with learning disorders. As adults, some
have problems with employment or social adjustment;
others have minimal difficulties. Early identification
of the learning disorder, effective intervention, and
no coexisting problems are associated with better out-
comes. Children with learning disorders are assisted
with academic achievement through special education
classes in public schools.◗ MOTORSKILLSDISORDER
The essential feature of developmental coordination
disorderis impaired coordination severe enough to
interfere with academic achievement or activities of
daily living (ADLs) (APA, 2000). This diagnosis is not
made if the problem with motor coordination is part
of a general medical condition such as cerebral palsy
or muscular dystrophy. This disorder becomes evi-
dent as a child attempts to crawl or walk or as an
older child tries to dress independently or manipu-
late toys such as building blocks. Developmental co-
ordination disorder often coexists with a communi-
cation disorder. Its course is variable; sometimes lack
of coordination persists into adulthood (APA, 2000).
Schools provide adaptive physical education and sen-
sory integration programs to treat motor skills dis-
order. Adaptive physical education programs empha-
size inclusion of movement games such as kicking a
football or soccer ball. Sensory integration programs
are specific physical therapies prescribed to target
improvement in areas where the child has difficulties.
For example, a child with tactile defensiveness (dis-
comfort at being touched by another person) might
be involved in touching and rubbing skin surfaces
(Spagna, Cantwell & Baker, 2000).◗ COMMUNICATIONDISORDERS
A communication disorder is diagnosed when a com-
munication deficit is severe enough to hinder devel-
opment, academic achievement, or ADLs including
socialization. Expressive language disorderinvolves
an impaired ability to communicate through verbal
and sign language. The child has difficulty learning
new words and speaking in complete and correct sen-
tences; his or her speech is limited. Mixed receptive-
expressive language disorderincludes the problems
of expressive language disorder along with diffi-
culty understanding (receiving) and determining the
meaning of words and sentences. Both disorders can
be present at birth (developmental) or they may be
acquired as a result of neurologic injury or insult to
the brain. Phonologic disorderinvolves problems with
articulation (forming sounds that are part of speech).
Stutteringis a disturbance of the normal fluency and
time patterning of speech. Phonologic disorder and
stuttering run in families and occur more frequently
in boys than in girls.
Communication disorders may be mild to severe.
Difficulties that persist into adulthood are related
most closely to the severity of the disorder. Speech20 CHILD ANDADOLESCENTDISORDERS 483