Autism Signs Seen by First Birthday 11-07-08

Signs of autism may be evident as early as 12 months of age, researchers here said.

Unusual ways of playing with and looking at toys appeared to predict autism and autism spectrum disorder in a prospective study of 66 infants, according to Sally Ozonoff, Ph.D., of the University of California Davis and colleagues.

The findings might help pediatricians diagnose and treat autism earlier, Dr. Ozonoff and colleagues said in the September issue of Autism.

"The finding that the unusual use of toys is also present early in life means that this behavior could easily be added to a parent checklist or quickly assessed during a visit to a pediatrician's office," Dr. Ozonoff said in a statement.

The American Academy of Pediatrics suggests that all infants be screened for autism twice before the age of two, and that pediatricians look for such things as language delays and lack of interest in people.

Such signs typically appear by the age of two, but there's no consensus on how early the repetitive and stereotyped behaviors characteristic of autism appear, the researchers noted.

The average age of autism diagnosis in the U.S. is three or older, Dr. Ozonoff said, but interviews with parents suggest that signs of the condition are often present earlier.

"About a third of parents notice signs before a child's first birthday," Dr. Ozonoff said.

To help clarify the issue, they enrolled 66 one-year-olds, 35 of whom had a sibling with autism or autism spectrum disorder and 31 who had a sibling developing normally.

They were observed and videotaped while playing with a round metal lid, a round plastic ring, a rattle, and a plastic baby bottle.

Normal behaviors with the objects included shaking, banging, mouthing, or throwing them; atypical uses included spinning, rolling, rotating, or unusual visual exploration, such as looking at them with peripheral vision.

The infants were later divided into three groups, based on assessments at 24 and 36 months -- nine children met criteria for autism or autism spectrum disorder, 10 were diagnosed as having other delays, and there were no concerns about the remaining 47.

The behaviors seen at 12 months were coded by observers who were blinded to the outcomes at 24 and 36 months, Dr. Ozonoff said.

Analysis found there were no group differences in banging, shaking, and mouthing the objects, although the group with other delays was significantly more likely to throw objects than the "no concerns" group, at P<0.001.

On the other hand, there were significant group effects for each of the atypical uses of objects:

"Our results suggest that these particular behaviors might be useful to include in screening tests," Dr. Ozonoff said, adding that more research is required to validate the findings.