Behavioural therapy sheds new light on Autism

Happy National Autism Awareness month to all readers! This month, we are going to talk about whether behavioural interventions and/or therapies for autism can change the brain. In 2017, I wrote a review paper about this topic. There is lots of evidence that behavioural interventions can change behaviour in autism. Most interventions focus on social behaviours with the goal of increasing social communication (such as eye contact, initiating social interactions, being responsive to social behaviours from others, following another person’s eye gaze, etc). It’s great that these interventions have been shown to improve behaviour, 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 behavioural therapies alone? If yes, this has exciting implications for how we think about ways to help kids with autism. Because there is no medication for the “core” symptoms of autism, we must rely on evidence-based behavioural interventions. And if those interventions can change how the brain works, it might help us make more individualised 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 anxiety and depression. Generally speaking, we think about depression and anxiety as brain-based, and although behavioural interventions (such as therapy) 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 behaviour alone—especially if a disorder is (in part) due to an imbalance of chemicals in the brain. However, since comparable medications do not exist for autism, it becomes more important to understand whether behavioural interventions can change the brain.

I think recent studies are a huge leap forward in autism research, and they excite me both as a neuroscientist and a clinician

I will discuss just one study that measured brain activity before and after a behavioural intervention. The authors used an evidence-based intervention called PEERS, which is designed to help teenagers 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 three 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 motivation 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.

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 behaviour.

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 neuroscientist and a clinician!