Autism is a disorder
of neural development characterized by impaired social
interaction and communication, and by restricted and repetitive behavior. The
diagnostic criteria require that symptoms become apparent before a child is
three years old. Autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize; how this occurs is not
well understood. It is one of three recognized disorders in the autism spectrum (ASDs), the other two being Asperger
syndrome, which lacks delays in cognitive development and language, and pervasive developmental disorder, not otherwise
specified (commonly abbreviated as PDD-NOS), which is diagnosed when the full set
of criteria for autism or Asperger syndrome are not met
Parents usually notice signs in the first two years of their child's
life. The signs usually develop gradually, but some autistic children first
develop more normally and then regress. Early
behavioral or cognitive intervention can help autistic children gain self-care,
social, and communication skills. Although there is no known cure, there have
been reported cases of children who recovered. Not many children with autism
live independently after reaching adulthood, though some become successful. An autistic culture has developed, with some individuals seeking a
cure and others believing autism should be accepted as a difference and not
treated as a disorder.
Characteristics
Autism is a highly variable neurodevelopmental
disorder[17] that first appears during
infancy or childhood, and generally follows a steady course without remission.[18] Overt symptoms gradually
begin after the age of six months, become established by age two or three
years,[19] and tend to continue through
adulthood, although often in more muted form.[20] It is distinguished not by a
single symptom, but by a characteristic triad of symptoms: impairments in
social interaction; impairments in communication; and restricted interests and
repetitive behavior. Other aspects, such as atypical eating, are also common
but are not essential for diagnosis. Autism's individual symptoms occur in the
general population and appear not to associate highly, without a sharp line
separating pathologically severe from common traits.
Unusual social development becomes apparent early in childhood. Autistic
infants show less attention to social stimuli, smile and look at others less
often, and respond less to their own name. Autistic toddlers differ more strikingly
from social norms; for example, they have less eye contact and turn taking, and do not have the ability to
use simple movements to express themselves, such as the deficiency to point at
things. Three- to five-year-old autistic children are less likely to exhibit
social understanding, approach others spontaneously, imitate and respond to
emotions, communicate nonverbally, and take turns with others. However, they do
form attachments to their primary caregivers.
Most autistic children display moderately less attachment
security than non-autistic children, although this difference disappears in
children with higher mental development or less severe ASD.Children with
high-functioning autism suffer from more intense and frequent loneliness
compared to non-autistic peers, despite the common belief that children with
autism prefer to be alone. Making and maintaining friendships often proves to
be difficult for those with autism. For them, the quality of friendships, not
the number of friends, predicts how lonely they feel. Functional friendships,
such as those resulting in invitations to parties, may affect the quality of
life more deeply.
Repetitive behavior
Autistic individuals display many forms of repetitive or restricted
behavior, which the Repetitive Behavior Scale-Revised (RBS-R) categorizes as
follows.
Stereotypy is repetitive movement, such as hand flapping,
head rolling, or body rocking.
- Compulsive
behavior is intended and appears to follow rules, such as arranging objects
in stacks or lines.
- Sameness is resistance to change;
for example, insisting that the furniture not be moved or refusing to be
interrupted.
- Ritualistic behavior involves an unvarying
pattern of daily activities, such as an unchanging menu or a dressing
ritual. This is closely associated with sameness and an independent
validation has suggested combining the two factors.
- Restricted behavior is limited in focus,
interest, or activity, such as preoccupation with a single television
program, toy, or game.
- Self-injury includes movements that
injure or can injure the person, such as eye poking, , hand biting, and
head banging. A 2007 study reported that self-injury at some point
affected about 30% of children with ASD.
No single repetitive or self-injurious behavior seems to be specific to
autism, but only autism
Screening
About half of parents of children with ASD notice their child's unusual
behaviors by age 18 months, and about four-fifths notice by age 24 months.] According to an article in
the Journal of Autism and Developmental Disorders, failure to meet any
of the following milestones "is an absolute indication to proceed with
further evaluations. Delay in referral for such testing may delay early
diagnosis and treatment and affect the long-term outcome".
- No babbling by 12 months.
- No gesturing (pointing, waving, etc.)
by 12 months.
- No single words by 16
months.
- No two-word (spontaneous,
not just echolalic) phrases by 24 months.
- Any loss of any language
or social skills, at any age.
Diagnosis
Diagnosis is based on behavior, not cause or mechanism.
Autism is defined in the DSM-IV-TR as exhibiting at least six symptoms total, including at least two
symptoms of qualitative impairment in social interaction, at least one symptom
of qualitative impairment in communication, and at least one symptom of
restricted and repetitive behavior. Sample symptoms include lack of social or
emotional reciprocity, stereotyped and repetitive use of language or idiosyncratic language, and persistent preoccupation
with parts of objects. Onset must be prior to age three years, with delays or
abnormal functioning in either social interaction, language as used in social
communication, or symbolic or imaginative play.Several diagnostic instruments
are available. Two are commonly used in autism research: the Autism
Diagnostic Interview-Revised (ADI-R) is a semistructured parent interview, and the Autism
Diagnostic Observation Schedule (ADOS) uses observation and interaction with
the child. The Childhood
Autism Rating Scale (CARS) is used widely in clinical environments to assess severity of
autism based on observation of childre
A pediatrician commonly performs a preliminary investigation
by taking developmental history and physically examining the child. If
warranted, diagnosis and evaluations are conducted with help from ASD
specialists, observing and assessing cognitive, communication, family, and
other factors using standardized tools, and taking into account any associated medical
conditions. A pediatric neuropsychologist is often asked to assess behavior and cognitive
skills, both to aid diagnosis and to help recommend educational interventions.
A differential
diagnosis for ASD at this stage might also consider mental
retardation, hearing
impairment, and a specific
language impairment such as Landau–Kleffner
syndrome. The presence of autism can make it harder to diagnose coexisting
psychiatric disorders such as depression.
ASD can sometimes be diagnosed by age 14 months, although diagnosis
becomes increasingly stable over the first three years of life: for example, a
one-year-old who meets diagnostic criteria for ASD is less likely than a
three-year-old to continue to do so a few years later. In the UK the National
Autism Plan for Children recommends at most 30 weeks from first concern to
completed diagnosis and assessment, though few cases are handled that quickly
in practice. A 2009 US study found the average age of formal ASD diagnosis was
5.7 years, far above recommendations, and that 27% of children remained
undiagnosed at age 8 years. Although the symptoms of autism and ASD begin early
in childhood, they are sometimes missed; years later, adults may seek diagnoses
to help them or their friends and family understand themselves, to help their
employers make adjustments, or in some locations to claim disability living
allowances or other benefits.
Management
The main goals when treating children with autism are to lessen
associated deficits and family distress, and to increase quality of life and
functional independence. No single treatment is best and treatment is typically
tailored to the child's needs. Families and the educational system are the main
resources for treatment. Studies of interventions have methodological problems
that prevent definitive conclusions about efficacy. Although many psychosocial interventions have some positive evidence,
suggesting that some form of treatment is preferable to no treatment, the
methodological quality of systematic reviews of these studies has generally been poor, their
clinical results are mostly tentative, and there is little evidence for the
relative effectiveness of treatment options. Available approaches include
(ABA), developmental models, structured teaching, speech and
language therapy, social skills therapy, and occupational
therapy.
Prognosis
There is no known cure. Children recover occasionally, so that they lose
their diagnosis of ASD; this occurs sometimes after intensive treatment and
sometimes not. It is not known how often recovery happens; reported rates in
unselected samples of children with ASD have ranged from 3% to 25%. Most
autistic children can acquire language by age 5 or younger, though a few have
developed communication skills in later years.Boys are at higher risk for ASD
than girls.
Several other conditions are common in children with autism. They include:
- Genetic
disorders. About 10–15% of autism cases have an identifiable Mendelian (single-gene) condition,
chromosome
abnormality, or other genetic syndrome, and ASD is associated with several
genetic disorders.
- Mental
retardation. The percentage of autistic individuals who also meet criteria for
mental retardation has been reported as anywhere from 25% to 70%, a wide
variation illustrating the difficulty of assessing autistic intelligence
- Anxiety
disorders are common among children with ASD; there are no firm data, but
studies have reported prevalences ranging from 11% to 84%. Many anxiety
disorders have symptoms that are better explained by ASD itself, or are
hard to distinguish from ASD's symptoms.
- Epilepsy, with variations in risk
of epilepsy due to age, cognitive level, and type of language
disorder.
- Several metabolic
defects, such as phenylketonuria, are associated with
autistic symptoms.
- Minor
physical anomalies are significantly increased in the
autistic population.
- Preempted diagnoses. Although the DSM-IV
rules out concurrent diagnosis of many other conditions along with autism,
the full criteria for Attention deficit hyperactivity
disorder (ADHD), Tourette
syndrome, and other of these conditions are often present and these comorbid diagnoses are increasingly
accepted.
- Sleep problems affect about two-thirds
of individuals with ASD at some point in childhood. These most commonly
include symptoms of insomnia such as difficulty in
falling asleep, frequent nocturnal
awakenings, and early morning awakenings.
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