Researchers have identified the hormone vasopressin as a possible biomarker for autism, a discovery that may have major implications in the understanding and treatment of the disorder.
This year's World Autism Awareness Day focused on empowering girls who have been diagnosed with autism spectrum disorder, as the condition is 4.5 times more prevalent in boys than girls. Vasopressin, however, was only tagged as a possible autism biomarker for boys.
Low Levels Of Vasopressin Linked To Autism In Boys
Vasopressin helps in blood pressure regulation and fluid retention, but within the brain, the hormone plays a role in social, sexual, and nurturing behavior. There are also interactions between vasopressin and male hormones such as testosterone, raising suspicions that it is somehow connected to autism.
In a study published in the Science Translational Medicine journal, researchers from UC San Francisco, UC Davis, and Stanford University explored whether vasopressin was indeed an autism biomarker.
The researchers selected 15 male rhesus monkeys with low sociability and compared them with 15 rhesus monkeys with high sociability. The experiment was conducted again in another group of 30 male monkeys.
The findings of the experiment were that the monkeys with low sociability had much less vasopressin in their cerebrospinal fluid compared with the monkeys with high sociability.
The researchers then tried the experiment on 14 boys with autism and seven boys without the disorder. The results were the same, in that the boys with autism had lower levels of vasopressin compared with the boys without it.
Why Finding An Autism Biomarker Matters
Identifying an autism biomarker will be a valuable discovery, as it will allow doctors to diagnose the disease early. Autism diagnosis is currently done with a behavioral checklist, but it is usually too late for behavioral interventions to affect the disorder's defining features of communications difficulties, repetitive behaviors, low social skills, and aggression.
If an autism biomarker is determined, it will enable a physiologic test that will determine at very early ages whether a child has the disorder, as well as its severity. Researchers may also be able to find new autism treatment.
"These are preliminary data that are compelling and interesting, but we still have a lot of follow-up to do," said Karen Parker, the leader of the study and the director of Stanford University's Social Neurosciences Research Program.
"What we consider this to be at this point is a biomarker for low sociability," said senior author John Capitanio, showing that there is much work to be done to be certain that vasopressin is an autism biomarker.