I want to start with blog entry by saying Happy National Awareness Month to readers in the United States!

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This month, we are going to talk about whether behavioral interventions and/or therapies for autism can change the brain. In 2017, I wrote a review paper about this topic and wanted to discuss it here as well. There is a large amount of evidence that behavioral interventions can change behavior in autism. Most interventions focus on social behaviors with the goal of increasing social communication (such as eye contact, initiating social interactions, being responsive to social behaviors from others, following another person’s eye gaze, etc). It’s great that these interventions have been shown to improve behavior, but since the scientific community generally agrees that autism is a brain-based disorder, studies have started measuring whether these interventions can change the brain.

The basic question is: can brain activity change from behavioral therapies alone? If yes, this has exciting implications for how we think about ways to help kids with autism. Because there is no for the “core” symptoms of autism, we must rely on evidence-based behavioral interventions. And if those interventions can change how the brain works, it might help us make more individualized interventions, or be able to intervene earlier and more effectively.

To draw an analogy with other brain-based conditions, let’s consider how we think about and . Generally speaking, we think about depression and anxiety as brain-based, and although behavioral interventions (such as ) are very helpful, we largely rely on the combination of medication and therapy for the most positive outcomes. The reason we think of medication as an important piece of the puzzle in depression and anxiety is because we understand that these disorders are brain-based, and know that it is difficult to change the brain through behavior alone—especially if a disorder is (in part) due to an imbalance of chemicals in the brain. On the other hand, since comparable medications do not exist for autism, it becomes more important to understand whether behavioral interventions can change the brain.

For the sake of time and space in this blog, I will discuss just one study that measured brain activity before and after a behavioral intervention. The authors used an evidence-based intervention called PEERS, which is designed to help with autism make and keep friends. This intervention involves weekly 90-minute meetings for 14 weeks, and includes both parent and child groups. The researchers measured brain activity from 3 groups: teens with autism who received PEERS, teens with autism who were in a waitlist group (meaning they received PEERS after the first group was finished), and neurotypical teenagers who did not receive the intervention.

The researchers measured brain activity at rest (which essentially means participants were told to look at an image on a screen for three minutes). Of particular interest was the difference in brain activity between the two halves of the brain--the left and right hemispheres. Over the past few decades, studies found that people who have more left hemisphere activity than right tend to be higher in approach and positive emotions. On the other hand, people with more right hemisphere activity than left tend to have more negative emotions and withdrawal. In autism, researchers have observed less left hemisphere activity and more right hemisphere activity compared to neurotypical individuals.

The researchers found that teens who received PEERS showed a significant decrease in right hemisphere activity, and an increase in left hemisphere activity. Teens with autism who did not complete the intervention did not have this brain activity change. Also, teens with autism who received PEERS had similar brain activity to neurotypical teens after receiving the intervention. Before receiving PEERS, both the waitlist group and intervention group had markedly less left hemisphere activity compared to neurotypical teens. Another exciting finding was the relationship between brain activity changes and behavior. Teens who had the most left-hemisphere activity after PEERS showed fewer parent-related symptoms of autism and more social contacts.

Overall, these results suggest that teens with autism who received the intervention had significant changes in brain activity, that those changes made the intervention group look more like the neurotypical group, and that those changes related to symptoms of autism and social behavior.

These results are very positive, but more research in this area is necessary. There are always more questions to be answered, but I think these types of studies are a huge leap forward in autism research, and excite me both as a and a clinician!