BALTIMORE—Some infants headed for a diagnosis of autism, or autism spectrum disorder as it’s officially known, can be reliably identified at 14 months old based on the presence of five key behavior problems, according to an ongoing long-term study described March 11 at the International Conference on Infant Studies.
These social, communication and motor difficulties broadly align with psychiatric criteria for diagnosing autism spectrum disorder in children at around age 3, said psychologist Rebecca Landa of the Kennedy Krieger Institute in Baltimore. In her investigation, the presence of all five behaviors at 14 months predicted an eventual diagnosis of autism spectrum disorder in 15 of 16 children.
“That’s much better than clinical judgment at predicting autism,” Landa noted.
Her five predictors of autism spectrum disorders among 14-month-olds at high risk for developing this condition include a lack of response to others’ attempts to engage them in play, infrequent attempts to initiate joint activities, few types of consonants produced when trying to communicate vocally, problems in responding to vocal requests and a keen interest in repetitive acts, such as staring at a toy while twirling it.
Accurate identification of infants likely to develop autism spectrum disorder by age 3 is particularly important because studies at Landa’s facility and several others indicate that intensive interventions with youngsters who display early warning signs and their parents often yield marked behavioral improvements. Interventions focus on teaching kids basic interaction and communication skills.
Landa’s study consists of 250 children who were first assessed at either age 6 months or 14 months. Comprehensive measures of social, communication and motor abilities were obtained at each child’s home and repeated at 18, 24, 30 and 36 months of age. The sample included 110 children considered to be at high risk for developing autism because they had older siblings already diagnosed with the same condition.
Preliminary evidence suggests that high-risk 14-month-olds who later develop autism display signs of delayed motor development as early as 6 to 7 months of age, Landa noted. In particular, these youngsters had difficulty keeping their heads stable when slowly raised from a prone position.
A fundamental derailment of postural development may accompany social difficulties typical of children with autism spectrum disorders, remarked psychologist Jana Iverson of the University of Pittsburgh. “The motor system is another place to probe for common underlying features of autism spectrum disorder,” Iverson said.
Psychologist Sally Rogers of the University of California, Davis, cautioned that much remains unknown about the early identification and treatment of autism. Infant siblings of older children with autism represent a special group that’s especially likely to show early signs of the same disorder, she suggested.
“I’m not sure the majority of children with autism spectrum disorder have predictive symptoms by 12 or 14 months,” Rogers said. In her own long-term studies, some children without autistic siblings show a gradual slowing of social and language development over several years that leads to autism, while others show no autism symptoms at all until being diagnosed with the disorder at age 4 or 5.