Autism Diagnosis Can Be Made at an Earlier Age

From 14 to 24 months, the following movements on scores were noted:

• Gesture inventory increased slightly in the early-diagnosis group whereas it decreased in the later-diagnosis group (P=0.007).
• The early-diagnosis group continued to have poorer inventory of consonants in syllables (P<0.004), words (P<0.001), and word combinations (P?0.001) compared with those who did not have autism.
• The later-diagnosis group showed declining frequency of shared positive affect and inventory of gestures whereas those without autism showed no change in these measures (all P<0.007).
• The later-diagnosis group made slower gains in rate of initiation of joint attention (P?0.01), inventory of consonants (P?0.005), and inventory of words (P<0.001) compared with controls.

"Our data validate parents' reports that autism spectrum disorder may appear after a period of nonautistic development," the researchers wrote, suggesting that children "reach the threshold for diagnosis at different times in the first three years of life."

Therefore, they said early screening would need to be repeated to catch the half of autistic children who do not present symptoms by 14 months.

Because social and communication development slowed before age two but some children diagnosed early made some gains thereafter, the findings "emphasize the urgency to determine whether very early interventions could alter the course of autism spectrum disorder," they added.