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You Actually Need Anxiety to Survive

Your brain's responses to stress are pretty smart.

As a non-writer and consummate procrastinator who doesn't do well with deadlines, it took me damn near three days to quell my nerves enough that I could sit down and write this article. A meager 500 words and I still found myself in the same high-alert mode that our ancestors faced when fending off beasts or scavenging for nourishment. Puts my ass to shame, of course, but also brings to mind the evolutionary origins of the anxious feelings rampant among modern young people. Sometimes it's helpful to reflect on a) why these feelings exist in the first place and b) the actual utility of anxiety. Yes, it can be useful.


There are three modes of anxiety that correspond to structures in the brain. The first form, known as preconscious anxiety, is most directly correlated to the perceived object of danger. For example, when a person sees something, like a rattlesnake, a neuronal signal is transmitted to the area of the brain known as the amygdala. The amygdala essentially functions as the brain's alarm system, responding to that signal as a control center that ropes in other body systems: pupils dilate, so you can better see the object of danger, heart rate goes up and blood flow increases to your peripheral musculature so you can get your ass out of there. Basically, your amygdala responds before you're conscious of what's going on. Preconscious anxiety is the fast track—it allows us to respond ultra quickly to a sometimes life-threatening danger.

The next form of anxiety is more removed from the object of danger. We call it anticipatory anxiety, and anyone who's tossed and turned while worrying about an important meeting the next day knows it well. With anticipatory anxiety, you feel anxiety at the conscious level while thinking about a future event. The conjuring of anxiety-provoking situations activates both the amygdala and also the cortex, the more complex processing center of the brain. The two brain regions battle it out, the former instilling a fear response ("I'm going to blow it!") while the latter tries to rationalize those unfounded fears ("I've held successful meetings before…"). While this kind of mental ping pong probably isn't the way you like to spend your time, some anticipatory anxiety can be beneficial because it can actually improve performance.

Interestingly, our anxiety around certain events is bound to our ancestral evolution. This is known as evolutionary anxiety. Several studies show that images of snakes and spiders, for example, elicit a somewhat universal fear response, more than other images. This is in part because the amygdala houses volumes of evolutionary memory where is an automatic fear of things that, historically, could have caused our ancestors' demise. (Plus, given that snakes are more of a predatory threat to primates than spiders, studies show that humans detect snakes more rapidly—supporting the idea of amygdala "memories" in which the level of anxiety corresponds to the evolutionary threat at hand.) To bring it a little closer to your everyday life, other research has shown that people can detect angry faces in a crowd much faster than happy faces. Evolutionary anxiety primes us to act in accordance with self-preservation—and ultimately to our own benefit.

Anxiety can appear to be useless at best and paralyzing at worst. But understanding both the mechanism and origins of this feeling allows us to be more aware of the function it serves. And in realizing that it can, in fact, serve a purpose, the hope is that we can accept our own anxieties and fears—maybe even enough to allow ourselves to sit down and write a few hundred words in time for a deadline.

Anita Rao, MD, is a psychiatry resident at the Northwestern University Feinberg School of Medicine.

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