What happens in the brain when we feel anxiety and fear?

When we feel anxiety or fear, the body’s autonomic nervous system is activated. Our hands sweat more, our pupils dilate and our heart beats faster. This can be measured experimentally. Researchers also study what happens in the brain.

text ANNICA HULTH photo MIKAEL WALLERSTEDT

There is a structure in the brain called the amygdala, which activates when we see something potentially threatening. It signals to other parts of the brain, we experience subjective fear and the body’s fi ght-or-fl ight response is activated.

“There are other parts of the brain that also assess the situation. The prefrontal cortex, for example, signals that it may not be so dangerous. ‘I've seen this before and I can handle it.’ The prefrontal cortex regulates the activity of the amygdala and alleviates the fear experience,” says Andreas Frick, docent in psychology.

With PET and MR cameras, researchers are able to monitor how different parts of the brain interact as well as which signalling substances are present in the brain during anxiety.

This works differently at different ages. During adolescence and up to the age of 25, people seem to have more diffi culty learning that something is safe after previous experience of it as threatening.

This is partly due to different parts of the brain maturing at different rates.

“The frontal lobe is not fully developed until the age of about 25, while the amygdala matures earlier. Therefore, teenagers have stronger fears but more diffi culties in regulating their feelings,” says Frick.

The most common treatments for anxiety are drug therapy or psychotherapy with cognitive behavioural therapy (CBT). Researchers are studying if it is possible to determine in advance which treatment is best for different individuals – drugs, psycho therapy or a combination of the two.

“We hope this will lead to better treatment choices in the future, so that people get help for their anxiety more quickly.”

A research collaboration with GO Adventure, a company that organises roof walks at Uppsala Castle, will provide additional knowledge about anxiety and fear. As many people are afraid of heights, research ers want to fi nd out what factors make some people brave enough to step out onto the roof while others are not. In turn, this could lead to methods that can help people suffering from anxiety disorders to attempt something that is scary but that they want to be able to do. ●

THE LIMBIC SYSTEM

Frontal lobe

Amygdala