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Scientists Found Autism Signs and Symptoms Linked to Brain Chemicals

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In a time where there is still much to learn about autism, new breakthroughs and knowledge are always exciting. This week, autism has been in the headlines twice thanks to the results of more studies being released. The first one reported that women who took antidepressants during pregnancy were more likely to have children with autism, though that study is already being discredited since it was widely exaggerated. The second study, which is much more promising, revealed that a neurotransmitter in the brain could be tied to autistic behaviors.

Earlier this week, captivating headlines suggested that women who took antidepressants during their pregnancy were 87% more likely to have children on the autism spectrum. People lashed back immediately, calling the study results damaging to women who truly have to take medication during their pregnancies to function. A closer look at the numbers revealed the claims to be quite exaggerated. Just 31 out of 2,532 children whose mothers had taken antidepressants (specifically, SSRIs) during their second or third trimester had autism. That’s compared to 40 children with autism out of 4,200 whose mothers had taken antidepressants in their first trimester and 1,008 autistic children out of around 140,700 without any exposure to the drugs.

More research will need to be done, of course, but it appears that pregnant women who have been prescribed antidepressants do not necessarily need to worry. Pregnancy can be a very stressful time, especially for women with mental conditions. Causing unnecessary panic or guilt does not help matters. As an autism specialist, it is best not to jump to any conclusions before getting all possible facts.

The second study results to be released this week look more promising. Scientists are claiming that they’ve discovered a specific chemical in the brain they believe is linked to autism. The Harvard University researchers found that autistic behavior is associated with a breakdown in the signaling pathway used by a major inhibitory neurotransmitter called GABA.

This is the first time in history that a neurotransmitter in the brain has been linked to autistic behavior. This theory, that the GABA signaling pathway plays a role in autism, has been shown in animal models, but never humans. While GABA has long been suspected of being a factor in autism, there was no proof that it was, until now.

Using a visual test that is known to prompt different reactions from autistic brains and normal brains, researchers have shown that those differences were associated with a breakdown in the signaling pathway used by GABA, one of the brain’s primary inhibitory neurotransmitters. The study was described in great detail in a December 17 article in Current Biology.

Autism is typically described as a disorder in which all the sensory input comes flooding in at once, so the idea that an inhibitory neurotransmitter was important certainly coincided with the clinical observations. There is also the fact that a lot of people with autism have seizures, and seizures are most likely runaway excitation in the brain. After the tests were conducted, researchers used magnetic resonance spectroscopy (a brain imaging technique) to measure the levels of certain neurotransmitters in the brain. Those with autism did show normal levels of excitatory neurotransmitters, but GABA was much lower than expected.

This study is promising for many reasons. If the findings hold true in children as well as adults, this could lead to an earlier diagnosis of autism. As of right now, it is impossible to diagnose autism in children who cannot speak yet. But that is when early intervention would be most effective. Children can obviously see before they can talk, so using visual tasks to screen children would allow for an earlier diagnosis.

It is important to note, however, that understanding the signaling pathway for GABA will not be a cure-all for autism. While this study is promising, there are many other molecules in the brain, and many of them are associated with autism in some form. While looking at the GABA story, we must also screen the autistic brain for other possible pathways that may play a role.

Still, scientists are very excited about this recent study. Autism is believed to be caused by a combination of genetic and environmental factors. This means that not every case will be able to be prevented, so the key to people on the spectrum leading a normal, fulfilling life will be early detection and proper treatment. With each new promising study, we get closer to that goal.

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