Researchers at the University of Miami have discovered a strong behavioral signal to help identify which infants who have an older sibling with autism spectrum disorder (ASD) will themselves be diagnosed with ASD in the following years.

The findings, published in the journal Developmental Science, show that high-risk infants who exhibit an “insecure-resistant attachment” to a parent are more than nine times more likely to receive an ASD diagnosis by age 3 than high-risk infants with secure attachments.

Secure babies typically explore their surroundings in their parent’s presence, and then seek to be close to the parent after an absence. Those classified with insecure resistant attachments explore less and are not often comforted by the parent’s return or soothing overtures.

Early recognition of an insecure-resistant attachment won’t prevent a future ASD diagnosis, say the researchers. However, it could lead to interventions that help infants who will develop an ASD form more secure social relationships, which is often difficult for people with the neurodevelopmental disorder.

“Insecure attachment patterns are generally associated with less optimal behavioral and emotional developmental outcomes later in life than secure attachments. And, there are critical interventions designed around attachment security–but not for infants at high risk for ASD,” said Katherine Martin, the lead author, who initiated the study as a Ph.D. candidate under the guidance of psychology professor Daniel Messinger.

“This new study,” Martin continued, “suggests the need for interventions for high-risk infants that specifically focus on sensitizing parents to social and emotional communication behaviors in infants identified as having insecure-resistant attachments.”

“This would hopefully be a means to decreasing resistant attachment behaviors and lowering the obstacles to acquiring social competencies, which are already impaired in children with autism.”

While many infants cry or show other signs of distress when a parent leaves, secure babies are soothed when the parent returns. That, however, is not the case with babies classified with insecure-resistant attachments.

“They not only cry when the parent leaves, but they never really settle down when the parent returns, which indicates that the infants are not confident in their ability to be calmed,” said Messinger, who has been studying the infant siblings of older children diagnosed with ASD for 15 years.

The new study builds on Messinger’s previous research. In one earlier study, he and his team discovered that about one in five infants of siblings with an ASD also will be diagnosed with an ASD, which is why they are considered high risk.

But with the aim of understanding the link between infant attachment security — the primary measure of the infant-parent relationship — and later ASD outcomes, Messinger and his students also looked at whether high-risk infants were more likely to be classified as insecurely attached to a parent than infant siblings of typically developing children.

And, they were not. “Although children may demonstrate resistant attachment patterns, that does not necessarily indicate they are headed towards autism,” said John D. Haltigan, a former student of Messinger’s and an author on both the previous and the current study.

“However, if you’re at high risk for autism and you have a resistant attachment, then you are more likely to have an ASD outcome.”

For the new study, the research team evaluated the attachment security of 95 infants who were classified by trained coders into four different attachment classifications when they were 15 months old. Then the researchers looked for a link between each infant’s attachment style and their ASD diagnosis, or absence of one, when the child reached age 3.

Overall, 16 of the 95 babies were high-risk infants who eventually developed ASD; 40 were high-risk infants who did not develop ASD; and 39 were low-risk infants who likewise didn’t develop ASD.

The researchers determined that high-risk infants with insecure-resistant attachments were more than nine times more likely to receive an ASD diagnosis than high-risk infants with secure attachments.

“There are a lot of questions about when early indications of autism emerge, and this is a pretty strong risk signal at 15 months among infants who have an older sibling with ASD,” Messinger said.

“And while we can’t stop a future ASD diagnoses, this suggests we should also consider attachment-related interventions for high-risk infants who show insecurity. We don’t do that at all right now.”

In addition to Messinger, Martin, and Haltigan, who is now at the University of Toronto, co-authors of the study included Messinger’s former postdoctoral student, Naomi Ekas, now at Texas Christian University, and Emily Prince, his current graduate student.

Source: University of Miami

High-Risk Infants With Insecure Attachment at Greater Risk for Autism