Learning to Diagnose Autism Spectrum Disorders
For children with autism, the sooner the disorder is identified
and treated the better the outcome for the child. Now researchers
report that it’s possible to detect autism in some children as
young as 14 months of age, the earliest the disorder has ever been
diagnosed. In other children, the scientists didn’t see definite
signs of autism until later—by about 2 years old.
Autism spectrum disorders (ASD) include several related brain
disorders, with symptoms spanning the spectrum from mild to severe.
People with ASD have extreme difficulties with social interactions,
communication and repetitive behaviors. The condition affects about
1 in 150 children, and it lasts a lifetime.
Most experts agree that early intervention—including behavioral
therapies, specialized teaching and medication—can improve
quality of life for years to come. Unfortunately, ASD is rarely
diagnosed before age 3.
Dr. Rebecca J. Landa at the Kennedy Krieger Institute in Baltimore
and her colleagues set out to study the progression of ASD in at-risk
children to see if earlier diagnoses could be made. The research
was supported by NIH's National Institute of Mental Health (NIMH).
As reported in the July 2007 issue of the Archives of General
Psychiatry, the scientists studied 107 children considered
to be at high risk for ASD because they had a sibling with the
disorder. An additional 18 children with no family history of
ASD served as the comparison group. The children's social and
communication skills were repeatedly assessed beginning at 14
months until about 3 years of age.
By the end of the study, 30 of the high-risk children had been
diagnosed with ASD. These children fell into two distinct groups.
Half of them—called the early-diagnosis group—had dramatically
lower social and communications abilities at 14 months of age than
the other groups. The other half—the later-diagnosis group—were
nearly indistinguishable from "normal" children at 14
months of age. However, by the time they were 2 years old, their
social and communication skills declined and approached the lower
scores of the early-diagnosis group.
These findings reveal two unique pathways that ASD may take during
early childhood. While ASD can be distinguished in some children
at just over 1 year of age, others appear to show only very subtle
differences from normal development until after 14 months of age,
when their skills begin to backslide.
The researchers note their findings may not be applicable to the
general population, in part because all the children with ASD in
their study had a familial risk. More research will be needed,
with larger groups of children, to better understand the developmental
patterns of ASD and to develop reliable tools for early diagnosis.
—by Vicki Contie
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