Hey everyone, whilst I was at VidCon I had the pleasure of filming a video with the wonderful
Kati Morton Kati: I am a licensed marriage and family
therapist and I have a mental health channel on YouTube where I talk about all things mental
health!
In case you didn’t know, as well as talking about science I also care a lot about mental
health, and we had quite a long discussion on the topic of PTSD, or post-traumatic stress
disorder.
When researching the “Here’s Why You Can’t Trust Your Memory?”
video, I learnt that whilst PTSD is actually usually diagnosed and treated as an anxiety
disorder, there is also some evidence for it potentially being a memory disorder.
So today we’re going to talk about what that means - and why I think it’s interesting
research!
[Intro by Cristina de Manuel & Caro Waro]
Now before deep-diving, I think the best thing is to hand over to Kati to explain what PTSD
and trauma is in a nutshell:
Kati: PTSD really is when we fear for our lives in a situation, it could be something
that we see someone else happen where we're like "oh my goodness, something terrible is
going to happen to them!
they could die, they could be in extreme danger, or we're in a situation where we feel like
we can't escape, we fear for our own life - that's essentially a trauma.
And when we have a trauma, the response that our body has after it because it's too much
for our brain to process, we experience PTSD.
And it's an anxiety disorder and it can be something where we have flashbacks of the
experience, we may have memory loss around the time, we may have memories that we feel
in our bodies that we're back in the experience...
In essence, some of the hallmark symptoms of PTSD such as the memory loss and consistent
flashbacks show a lack of memory consolidation by the brain.
And so I asked Kati to talk a bit more about the effect of trauma on declarative memory.
Kati: and the best way I find to describe traumatic memories are by comparing them to
happy, normal memories.
So let's say Inés and I go on a vacation and we go skydiving, and we eat wonderful
food, and we go on bike rides, just have the time of our lives - and we come back - my
brain, as I'm doing this is like, writing pretty stories and putting all these files
in files and putting them in the family cabinet and shutting the drawer.
It all makes sense, it's filed away nicely - beginning, middle, end.
Clear.
Wonderful.
When we have a trauma- this is why I love Inside Out, have you guys seen the movie Inside
Out?
If you haven't, I highly recommend it, because then I picture those little nice memories
as those marbles in Inside Out and so we file them away and we're rolling them into our
long term memory - when we have a trauma it's like someone has thrown the marble and it's
splintered and it shoots into all of those other memories, all those other file folders,
it's like chaos, it's like the papers have just gone everywhere and we have to slowly
put them back together in a cohesive story: beginning, middle, end.
We actually talked quite a bit more about PTSD, different forms of therapy, treatment
and certain controllable risk factors from childhood - so if you want to find out more
about that, I encourage you to watch the whole thing over here on Squeak Code.
However, I wanted to pause on this topic because I want to focus on the relationship between
PTSD and memory.
One of the key symptoms in PTSD is that the traumatic memory is not properly processed,
which amongst other unpleasant symptoms leads to the intrusive flashbacks, as if the memory
were constantly being relived in the present.
And not only that, but people with PTSD often report having difficulty recalling other events
properly even if they were unrelated to the trauma itself, which has led to the hypothesis
that people with PTSD may process their memories differently.
There is actually some neurobiological evidence for this as well: severely stressed animals
have higher levels of glucocorticoids, which are the stress hormones, in their hippocampus,
which is the part of the brain that processes memory (well, does part of the processing)
and they actually perform really badly on memory tests.
And, adults, although not children, with PTSD have smaller hippocampi than those without.
And in fact, there are two different models which aim to explain this relationship between
memory dysfunction and PTSD and they lie at the opposite end of the nature vs. nurture
scale.
One model suggests that developing PTSD is what leads to the abnormality in memory, meaning
that the memory problems could be environmental.
The other model suggests that there are inherent genetic factors that lead to certain memory
and cognitive deficits that predispose someone to PTSD, and currently I’d say there’s
more research supporting this model.
For example, there are actually studies that looked at identical twins where one was a
war veteran with PTSD, and the other one had never been exposed to a traumatic event, and
researchers found that both had similar memory deficits and smaller hippocampi.
Other studies have shown that those with a poorer performance on tests such as working
memory, processing speed and verbal intelligence, were more likely to develop PTSD symptoms
following a natural disaster, and both of these suggest that there may be pre-existing
factors or genes that can predispose someone to develop PTSD.
It is thought that perhaps a lower availability of cognitive resources is what prevents traumatic
memories from being processed properly, thus leading to PTSD.
And this of course has consequences in therapy, as it means that the memory deficits could
also affect or impair how well people respond to therapy.
However, I personally think it's a really exciting new avenue for research because it
could be evidence for neurobiological markers that could be assessed to perhaps a) detect
people who could be at greater risk of developing PTSD and provide them with more resources
to prevent it and b) to provide new ways of therapy that could target memory processing
and reconsolidation, such as by targeting drugs and therapy at specific times after
trauma which could help specifically with memory reprocessing.
The research is definitely in its early steps, but I’m hopeful it will lead to better treatments
in the future!
I really hope you found today’s episode interesting and thank you so much Kati for
helping me out!
We also made a video over on Kati’s channel on the differences and similarities between
Tourette’s and OCD, which I get asked about a lot, so do go check that out!
Our full chat about PTSD is on my mental health channel, Squeak Code.
And, if this is your first time on Draw Curiosity - then welcome!
I make videos about the interesting bits of science that draw my curiosity and it is great
to have you here - you can see some of the videos I’m most proud of here and that other
people seem to like the most over here!
All videos and research papers that I've talked about are linked in the description, and as
always, thank you so much for watching me and I’ll see you in the next one!
Bye!
[MUSIC: Thastor & CryoSleepKitten]
[ART&ANIMATION: Caro Waro & Cristina de Manuel]
[Hosts: Kati Morton and Inés]
[Translated by {your name} into {language}]