What happens in the brain when we experience a panic attack?
—Davide Razzoli, Italy
Paul Li, a lecturer of cognitive science at the University of California, Berkeley, explains: Before going onstage to give a presentation, you notice your breathing becomes heavy, your hands tremble and you feel faint. Though frightening, these symptoms are not life-threatening; rather they are indicative of a panic attack.
We know a fair amount about the physiology of a panic attack, but we have only recently started to understand how it affects our brain chemistry. Panic attacks are episodes of intense fear or apprehension. Sufferers often report thinking that they might be dying, choking or going crazy. They may also feel like they are experiencing a heart attack or about to black out. These episodes usually begin abruptly, reach their peak within 10 minutes and end within half an hour.
When people feel stressed, their sympathetic nervous system typically revs up, releasing energy and preparing the body for action. Then the parasympathetic nervous system steps in, and the body stabilizes to a calmer state. If the parasympathetic nervous system is somehow unable to do its job, a person will remain fired up and may experience the heightened arousal characteristic of a panic attack.
Recently researchers have identified certain regions of the brain that become hyperactive during a panic attack. These regions include the amygdala, which is the fear center of the brain, and parts of the midbrain that control a range of functions, including our experience of pain. A study performed by scientists at the Wellcome Trust Center for Neuroimaging at University College London used functional MRI to locate which specific brain regions kick in when a person senses an imminent threat. They found activity in an area of the midbrain called the periaqueductal gray, a region that provokes the body’s defensive responses, such as freezing or running. Dean Mobbs, the lead author on the study, wrote: “When our defense mechanisms malfunction, this may result in an overexaggeration of the threat, leading to increased anxiety and, in extreme cases, panic.”
By identifying brain regions involved in panic attacks, such studies can improve our understanding of anxiety-related disorders and in turn help researchers find better treatments.