By SHIRLEY S. WANG - The Wall Street Journal

The screening used in the study also flagged some babies who later turned out to be developing normally, raising a false alarm for families. But early diagnosis and treatment of autism and other developmental delays are thought to improve outcomes, and researchers said the benefits of early intervention outweighed the downsides.

“This does show that a respectable percentage of babies who eventually get a diagnosis [of autism-spectrum disorders] show subtle signs at one year,” said Karen Pierce, lead author of the study and assistant director of the University of California, San Diego’s Autism Center of Excellence. “The only chance we have right now in changing that path to having full-blown symptoms is early intervention, and there’s no reason not to try.”

Autism, characterized by deficits in social interaction and communication, is extremely difficult to detect in very young children, some experts say. Children often aren’t diagnosed until age 2 or 3, when symptoms like lack of engagement and eye contact with parents and peers become more obvious.

But in Thursday’s study, UC-San Diego researchers found pediatricians were able to use a five-minute questionnaire to successfully identify potential problems in communication and language skills during a 12-month-old’s wellness checkup. Questions included whether parents could tell if their infant was happy or upset, or responsive to certain cues.

Of the nearly 10,500 infants screened, 184 scored lower than expected and were referred for further evaluation and tracked for up to three years. Ultimately, 32 of them were diagnosed with an autism-spectrum disorder, while an additional 101 were determined to have a language or developmental delay or a related condition.

“This is the first and only study to demonstrate the feasibility of using a really broad screening measure like this in a medical setting,” said Lisa Gilotty, who leads the research program on autism-spectrum disorders at the National Institute of Mental Health, which helped fund the study.

Based on previous research, the study likely identified about half of children who later would turn out to have autism.