Are Anxious Kids' Brains Wired Differently?
Research demonstrates stronger fear signals in the brains of anxious kids.
Posted May 04, 2020
If there’s one thing I’ve learned treating anxious kids, it’s that the anxious brain is one of the most creative forces on the planet. Anxious kids can think of things to worry about that wouldn’t even occur to most of us. It’s like anxious brains are wired differently.
Using functional MRI technology, which allows researchers to see exactly which parts of the brain are working during a particular task, the researchers pinpointed a difference in the brains of anxious children and their more typically developing peers. The difference lies in how the "fear center" of the brain (the amygdala) communicates with an area of the brain called the dorsolateral prefrontal cortex. They discovered a much stronger “fear signal” coming from the amygdala of anxious children. (For an explainer video demonstrating how fMRI works, click here.)
Procedure: or, How to Stress Kids Out for Science!
The children were recruited from a much larger study of social and emotional development. All of the children were from a low-income population that often faces high levels of adversity. All of the children were between 10-11 years old, and approximately half were male. While only 45 children were ultimately recruited, due to the study design, this was considered an adequately sized sample. The children were administered some standard anxiety and stress self-report tests, and then introduced to the task.
While under fMRI monitoring, the children were exposed to neutral images, such as the picture of a person strolling outside, or aversive images, such as the picture of a car crash. The children were given instructions while viewing the images. For all the neutral images, and half the aversive images, they were asked to look at them and respond naturally. They were asked to rate their emotional reaction after each one. For example, after seeing a picture of a car crash, they were asked: On a scale of 1-10, where 1 is “not distressing at all” and 10 is “very distressing,” what number would you assign this picture?
After that, the children were trained in a cognitive reappraisal technique. They were told to tell themselves a story that would make the image seem less threatening. For example, “the car crash looks bad, but the airbag inflated, and no one got hurt.” The children were then exposed to new aversive images, and asked to cognitively reappraise them, then rate their emotional reactions. (For more about how cognitive reappraisal is used in anxiety treatment, click here and here.)
All the children reported less intense negative emotions after being directed to reappraise the images. However, the anxious children’s brains were doing something different than those of their peers. The fMRI data showed the strength and direction of interactions between the amygdala, the “fear center” of the brain, and the dorsolateral prefrontal cortex, the “reasoning center” of the brain. In all children, the amygdala and the dorsolateral prefrontal cortex were communicating. The amygdala was sending out fear signals, while the dorsolateral prefrontal cortex was trying to regulate the fear.
In the anxious children, the amygdala was sending out stronger and more intense signals to the dorsolateral prefrontal cortex, but the dorsolateral prefrontal cortex was not sending more intense signals back. Metaphorically, it’s like the amygdala’s “shouting” was drowning out the attempt of the dorsolateral prefrontal cortex to reason with it. The dorsolateral prefrontal cortex was losing the battle to regulate the brain’s fear response. We can think of the amygdala’s signal as “bottom up,” and the dorsolateral prefrontal cortex’s signaling as “top down.” So the “bottom up” signal was stronger than the “top down” signal.
In addition, the anxious children reported more intense initial reactions to the aversive images, less ability to regulate emotional reactions to those images, and more impulsive reactions when trying to reappraise the aversive images.
How Worry and Stress Reactivity Work Together
Worry is a cognitive tendency. Some children tend to worry more than others. Their brains seem to conjure up more “worst-case” scenarios, and they tend to think about those worries more. Stress reactivity is a temperament trait. Some children are born reactive. When they see something new, or aversive, they have a strong reaction to it. For example, their hearts begin to race. Stress reactivity is not something we have conscious control over, it’s how our bodies and brains are wired to respond to stress. (For more about how temperament predicts stress reactivity, click here.) Researchers have long posited that both worry and stress reactivity need to be addressed in treating anxious children.
Children with high levels of anxiety—who report more frequent and intense worrying—reported more intense reactions to the aversive images, less ability to regulate their emotional responses to those images, and more impulsive reactions during reappraisal. Children with temperamentally high stress reactivity tended to have less controlled, more impulsive reactions when trying to reappraise aversive images. That means that both worry and stress are much more intense for kids with anxiety disorders.
The current study supports the Attention Control Theory, which suggests that excessive anxiety tends to amplify “bottom up” signals from the amygdala. This eats up a lot of the bandwidth the dorsolateral prefrontal cortex has to regulate emotions. As we said before, the bottom up amygdala signal is “shouting” at the dorsolateral prefrontal cortex. It’s kind of hard to reason and regulate emotions when someone is shouting at you, right?
Implications for Practice and Parenting
We know that anxious children can use cognitive reappraisal strategies. It’s not a deficit in understanding or ability. I’ve had patients tell me “I’ve talked myself through it, but I still feel the anxiety.” Unless we also work on helping patients regulate their initial stress response, we cannot expect anxiety to ameliorate. It’s not enough to teach positive thinking or mindfulness. Both have to be taught together, in conjunction with one another. The child must learn to regulate stress reactions—to mindfully lower heart rate using techniques such as deep breathing or progressive muscle relaxation—while at the same time engaging in reappraisal.
In addition, this study suggests that we need to intervene with reactive children before they reinforce their worry tendencies. Neuroplasticity can be our enemy when it comes to anxiety because behavior that is rehearsed is reinforced. Negative thinking and worry are automatic to reactive kids, but positive thinking and reappraisal must be taught, rehearsed, and overlearned before they can be effective. Teaching reactive kids how to reappraise their worry thoughts when they’re very young, practicing those skills with them, and helping them lower the intensity of their reaction might help prevent them from ever developing anxiety disorders in the future. We can literally parent preventatively. (To read more about parenting to prevent future disorders, click here and here.)
© Robyn Koslowitz, 2020
Warren S.L, Zhang Y., Duberg K., Mistry P., Cai W., Qin S., Bostan S.-N.,Padmanabhan A., Carrion V.G & Menon V., Anxiety and stress alter decision-making dynamics andcausal amygdala-dorsolateral prefrontal cortex circuits during emotion regulation in children, BiologicalPsychiatry (2020), doi: https://doi.org/10.1016/j.biopsych.2020.02.011.