Autism therapies to reduce the symptoms might have the chance of success if they begin in the first year of life, before the brain structure changes.
A brain structure starts to enlarge between 6 and 12 months of age in two-year-old children diagnosed with autism spectrum disorder (ASD), suggests a study funded by the National Institutes of Health. ASD is a complex developmental disorder that affects how a person behaves, interacts with others, communicates, and learns.
‘The faster the rate at which the brain structure amygdala grows, the greater the severity of autism spectrum disorder symptoms at 24 months.’
The amygdala is a brain structure involved in the processing of emotions, such as interpreting facial expressions or feeling afraid when exposed to a threat.The study included 408 infants, 270 of whom were at a higher likelihood of ASD because they had an older sibling with ASD, 109 typically developing infants, and 29 infants with Fragile X syndrome, an inherited form of developmental and intellectual disability.
Researchers conducted MRI scans of the children at 6, 12, and 24 months of age. They found that the 58 infants who went on to develop ASD had a normal-sized amygdala at 6 months, but an enlarged amygdala at 12 months and 24 months.
The infants with Fragile X syndrome had a distinct pattern of brain growth. They had no differences in amygdala growth but enlargement of another brain structure, the caudate, which was linked to increased repetitive behaviors.
The study findings are published in the American Journal of Psychiatry.
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