Now, a research team at the Stanford University School of Medicine and Lucile Packard Children's Hospital is recruiting autistic and typically developing children and their parents for a study of whether one particular biological mechanism plays a role in causing the disorder.
The researchers will test whether impaired social behaviors in autism are linked to levels of the hormone oxytocin. In healthy individuals, oxytocin primes maternal behavior, enhances social interactions, increases the ability to read facial expressions and recognize individuals, and boosts trust and empathy. Preliminary research has hinted that autism may be associated with oxytocin deficits, but those studies involved limited samples.
"We're hoping to find a biomarker for autism," said lead researcher Karen Parker, PhD, assistant professor of psychiatry and behavioral sciences at Stanford. Parker and colleagues will study 50 children ages 3 to 12 who have been diagnosed with autism; 50 of their healthy siblings, some of whom may have moderate social or emotional impairments; and 50 typically-developing children who do not have siblings with or a family history of autism. The researchers will test whether oxytocin signaling falls on a spectrum that matches variations in social behaviors. If the findings show a correlation between oxytocin and behavior, further research will be needed to determine whether a causal relationship exists.
"Autistic" and "typical" social behaviors exist on a continuous spectrum, Parker explained. That means children diagnosed with autism have varied degrees of social and emotional impairment, and typically-developing children also vary in their social and emotional function. The researchers hope that participants in the study will represent the whole of the behavioral spectrum.
Children in the study will complete an IQ test and several standard psychological and behavioral tests. Each child will give one blood sample, which will be used to measure oxytocin levels and to look for tiny variations in the gene that encodes the oxytocin receptor. The researchers suspect such gene variations change how the oxytocin signal is transmitted, and will test whether certain variations might be characteristic of autism.
Parker is collaborating with child psychiatrist Antonio Hardan, MD, director of the Autism and Developmental Disabilities Clinic at Packard Children's Hospital, and Joachim Hallmayer, MD, associate professor of psychiatry and behavioral sciences at Stanford. The study is funded by a two-year, $300,000 award from the Simons Foundation Autism Research Initiative.
"There's a real need to recognize that autism is a biological disorder," Parker said. "Right now, we spend millions of dollars on care for these kids, but we have no proper treatments." If her team's work confirms an oxytocin-autism link, it could lead to development of a blood test for autism, raising the possibility of earlier and more effective treatment for the disorder, Parker said. She also speculated that her research might show whether oxytocin or similar compounds could be used as autism treatments, or as prophylactics to prevent full-blown autism in children who show early signs of the disorder.
"Having the tools to begin treatment earlier would constitute a huge quality-of-life improvement for these kids," she said.
Parker noted that families with healthy children are much needed as volunteers for the research. "We can't do this study in the absence of a comparison group," she said. Participating in the research is a concrete way for families with typically-developing, healthy children to help those who are struggling to raise a child with autism, she said. And all parents in the study will get to learn about their own child's makeup. "Parents might think, 'Wow, I have a super-social child. I'm curious about the biology of that,'" Parker said. "We'll be able to give them information they could never get from a typical doctor's office visit, since oxytocin measurements and behavioral assessments are not routinely performed in clinical settings."
The behavioral tests will take about three hours for typically-developing children and siblings of autistic children to complete. Children with autism will undergo a complete diagnostic assessment in addition to the behavioral tests, for a total of about six hours of testing. In addition, all parents will be asked to complete a one-hour phone interview. Each child-parent pair will be compensated $50 for their time. Parents will also be able to request a summary of their child's IQ and behavioral test results after they complete the study.
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