A single dose of the hormone oxytocin administered via nasal spray enhances brain activity in key regions, temporarily improving social information processing in children with autism spectrum disorder (ASD), new research suggests.
The double-blind, placebo-controlled imaging study of 17 children and adolescents with ASD showed that those who received intranasal oxytocin had increased activity in brain regions associated with reward, social perception, and emotional awareness compared with their counterparts in the placebo group.
"We found that brain centers associated with reward and emotion recognition responded more during social tasks when children received oxytocin instead of the placebo. Oxytocin temporarily normalized brain regions responsible for the social deficits seen in children with autism," lead author Ilanit Gordon, PhD, Yale Child Study Center, Yale University, in New Haven, Connecticut, said in a release.
Dr. Gordon added that the study is the first to evaluate the effect of oxytocin on brain function in children with ASD.
The findings were published online December 2 in the Proceedings of the National Academy of Sciences.
Mixed Results
In typically developing adults, intranasal oxytocin has been shown to enhance processing of social stimuli and heighten activity in neuroanatomic brain structures involved in processing socially meaningful stimuli.
In addition, behavioral studies in children and adults suggest that a single dose of intranasal oxytocin improves social interaction and comprehension of affective speech. It has also been shown to reduce repetitive behaviors, improve social cognition, and increase understanding of others' mental states.
However, the authors note that results from clinical trials examining the effect of daily administration of oxytocin on behavior in children and adults have been "mixed at best."
To examine the neural basis of oxytocin's effects, the researchers conducted a randomized, double-blind, crossover functional magnetic resonance imaging (fMRI) study.
They investigated the effects of a single intranasal administration of oxytocin on brain activity in 17 high-functioning children and adolescents aged 8 to 16.5 years with ASD. They note that previous reports have not included individuals younger than 12 years.
The Social Brain
The researchers hypothesized that "during a task involving social judgments, OT [oxytocin] vs Placebo would heighten brain activity in the neural circuitry that supports reward (dorsal and ventral striatum and nucleus accumbens [NAcc], as well as social attention and social cognition (eg, posterior superior temporal cortex, cingulate, precuneus), that is, the 'social brain.' "
Participants were randomly assigned to receive either oxytocin or placebo nasal spray on 2 consecutive visits. Forty-five minutes after administration, brain function was assessed using the Reading the Mind in the Eyes Test (RMET), a validated fMRI emotion judgment task.
The results showed "oxytocin increased activity in the striatum, the middle frontal gyrus, the medial prefrontal cortex, the right orbitofrontal cortex, and the left superior temporal sulcus."
The researchers also reported that oxytocin increased activity during social judgments and decreased activity during nonsocial judgments in the striatum, nucleus accumbens, left posterior superior temporal sulcus, and left premotor cortex.
The researchers also tested oxytocin concentrations in saliva at baseline and 30 minutes after administration and found they were positively associated with enhanced brain function.
Potential Clinical Utility
These discoveries, the researchers write, are "particularly important given the urgent need for treatments that target the core social dysfunction in ASD."
"The functional neural attunement we demonstrated might facilitate social learning, thus potentially bringing about long-term change in neural systems and subsequent behavioral improvements," the authors conclude.
The researchers predict that clinically, oxytocin may be most useful when administered just prior to proven behavioral treatments that "provide opportunities for feedback and learning in supportive social contexts."
The authors report no relevant financial relationships.
Proc Natl Acad Sci. Published online December 2, 2013. Abstract
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Cite this: Oxytocin 'Normalizes' Social Deficits in Kids With Autism - Medscape - Dec 10, 2013.
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