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About 10% of people who go through a traumatic experience end up developing post-traumatic stress disorder, or PTSD. This condition is characterized by periods of intense fear, intrusive memories, and feelings of helplessness.

And while there are ways to treat it, it would be awfully nice if we could just prevent these symptoms from developing in the first place. I know, I know. Right now, you're probably saying to yourself, “Wishful thinking, Anthony!

Let's just get rid of all the trauma in the world!” But hear me out. According to some research, there might actually be a way to prevent PTSD from developing — without totally changing society. It's not quite ready yet, but there's some promising evidence in its corner.

And maybe the best part? This treatment is one of the most common drugs in the world. It's called hydrocortisone.

It's a medicinal version of the human stress hormone cortisol, and it's been used for decades in everything from allergy creams to arthritis medications. But even though it's been used for years, we didn't know it might be helpful for PTSD until the late ‘90s. Around then, a researcher noticed that hospital patients who had received hydrocortisone for septic shock also seemed to have better mental health outcomes.

And eventually, a follow-up study backed this up. It looked at people who had potentially-traumatic major surgery. And it found that those who'd received hydrocortisone had fewer PTSD symptoms and a higher quality of life six months later.

Since then, many studies have investigated this with similar results. But, unfortunately, this doesn't mean that psychiatrists can just start giving out hydrocortisone shots to all their patients. Based on the research, these injections are only particularly effective during a tiny window: They work best within about 12 hours after someone experiences a trauma.

Still, if you can hit that window, you can potentially reduce or prevent future PTSD symptoms. The reason why this window exists — and why hydrocortisone seems to help at all — might have to do with how our brains make fear-related memories. When we experience something scary or traumatic, certain parts of our brain — including the amygdala and hippocampus — get to work.

They start making new connections and short-term memories about what scared us and what we were doing at that time. Then, later, the brain solidifies these short-term memories into long-term memory. This process is known as fear conditioning.

Of course, when something scary happens, our bodies aren't just making memories. They're also going through a physical response, which includes producing stress hormones like cortisol. Cortisol helps suppress non-essential functions, like digestion, during life-or-death scenarios.

But it also has another job — one that might be a little counter-intuitive, given its role as a stress hormone. It's a key part of a negative feedback loop our bodies use to turn the stress response off. Among other things, it helps the brain chill out and stop creating or storing those new fear memories.

And that's where PTSD comes in. This condition is often understood as a kind of runaway fear conditioning. The idea is that the brain associates certain cues with fear too strongly and initiates an extreme response.

And according to some studies, that might be because a person had low cortisol levels when they experienced a trauma. Without enough of this hormone, their brains might have had trouble turning off their fear circuitry. They'd just keep building and storing those fear memories, until their brains initiate an extreme response whenever they recall what happened.

Now, there have been some inconsistencies in this research, and not every paper supports this hypothesis. But this connection has popped up enough that scientists are seriously investigating it. After all, it would explain why a timely injection of hydrocortisone would prevent PTSD symptoms from developing.

We'll need to learn more before we can say anything for certain, because exactly how stress hormones affect memory can be complicated. But the more scientists have looked into it, the more there really does seem to be something there. That said, hydrocortisone isn't ready to be commonly used for PTSD just yet.

We still need high-quality trials to replicate previous findings, investigate inconsistencies, and nail down things like dosage, timing, and administration. And even once we do that, there are some logistics to figure out, too. To work, hydrocortisone would need to be given to people really quickly after they experienced trauma.

So it would need to be ready and available in places like emergency rooms or ambulances. That would require some extra logistics, like specialized training to identify and follow-up with people at risk of developing PTSD. After all, you wouldn't want to just give this stuff to everyone who walked in the door.

Cortisol is still a stress hormone so it has a lot of effects in the human body. High levels have been linked with sleep and digestive problems, and anxiety, for instance. But, even though there's still a fair amount to learn and unpack, the idea of being able to prevent PTSD at all is really exciting.

And it gives us something to hope for. Thanks for watching this episode of SciShow Psych! If you want to help us make more content like this, there's an awesome team of people that makes SciShow possible: our patrons on Patreon.

Without them, we couldn't make so much free educational content. So if you're a patron, thank you! You really do make all of this happen.

If you want to learn more about supporting the show and joining our patron community, you can go to patreon.com/scishow. [ ♪OUTRO ].