Who Gets PTSD and Why?
Approximately 50-60%
of people living in the US report having at least one traumatic event in their
lifetime1. These traumatic events usually cause symptoms in the days
and weeks that follow. These symptoms might be flashbacks, nightmares, feeling
numb and detached from people, and avoidance of trauma reminders. Obviously,
people who work as first responders (soldiers, police, paramedics,
fire fighters, etc.) are more likely to experience traumatic events and develop Post
Traumatic Stress Disorder (PTSD).
Fortunately, for many
people these initial PTSD symptoms decline naturally in the 3-6 months
following the event. However, research shows that anywhere from 5% to 30% of
sufferers will actually develop chronic PTSD.
In the movies,
characters who have PTSD (like a soldier home from war) are usually startled by
loud sounds, or the director might show jumbled images that are supposed to
represent flashbacks to the trauma.
These movie scenes are
true and accurate, but come nowhere near the real range of intrusive thoughts
and memories that get triggered in those with PTSD
First, there are the
more ‘obvious’ memories and thoughts associated with a traumatic event – seeing
a dead body and blood, or hearing gunshots. However, it can sometimes be the ‘less
obvious’ things that get traumatically remembered - gasoline, smoke, article of clothing, someone’s facial
features, or even common smells like cleaning products (accidents and crime
scenes need to be cleaned and sanitized at some point).
When getting robbed at
gunpoint, someone with PTSD might remember a facial feature of the criminal
(“I’ll never forget his teeth and smile”) as much as they remember the gun.
The point is that
traumatic events can “burn” memories into the brain that cause unwanted
thoughts and images to pop into the person’s head. It also makes them want to
avoid things associated with the memory.
Not only does PTSD
produce memories that are highly disturbing and intrusive, but it also tends to
change the person’s fundamental beliefs. For example, they might have negative
beliefs about:
·
Themselves
(“I will never be the same person”)
·
Other
people (“People are dangerous ”)
·
The world
(“Unless you stay alert, this world will eat you alive”)
·
Work
activities (“The risk of dying in my job is very high”)
·
Basic
activities (“The risk of dying while driving is very high”)
It is this combination
of haunting memories and new beliefs that play a large causal role in someone developing
PTSD.
In the past number of
years, scientists have been working to develop treatments that would erase
traumatic memories. They have had some initial success in studies with rats.
For example, one recent study showed that exposing rats to a gas called Xenon appeared
to erase their fear memories. This type of research is still in the early
stages, and there are no treatments at this time that allow us to erase the
traumatic memories of PTSD sufferers.
However, psychological
treatments can have large and positive effects for those with PTSD. For
example, psychologists have learned a lot about the causes of fear and traumatic memories, based on hundreds (if not thousands) of research studies. They've used this knowledge to develop and hone certain treatments for PTSD.
One of the findings
from this research is that we never really erase memories through therapy. During
a traumatic event, the brain seems to create a number of very strong
connections between fear/trauma and various things present during the
trauma (ex: image of a gun, smell of smoke, sound of someone screaming, etc.).
For example, a police
officer who witnesses a suicide via gunshot to the head, might develop a whole
memory system that links the following things with fear:
·
Guns
·
A type of
sweater (similar to the one worn by victim)
·
Blood
·
Certain verbal
expression (if the victim said “Life sucks” or “I’m outta here” just before
pulling the trigger)
·
A
particular facial expression of squeezing eyes closed (victim did this before
shooting)
Now, the police
officer has intrusive thoughts about the trauma whenever his son squeezes his
eyes shut or when he sees someone wearing a certain sweater.
He also is more likely
to avoid things like TV shows with violence.
Arguably the best
treatment of PTSD is a type of therapy called Cognitive Behavioural Therapy (CBT).
This type of therapy requires the therapist to use a procedure called “exposure.”
When psychologists use
exposure they have the person face the very things that remind them of
the trauma. They look at images, watch videos, smell objects, and hear sounds that
cause them to feel anxious.
Sound cruel and
unusual? That is sometimes the reaction of some of my clients – “why would I do
that when I am trying to forget this stuff?”
We use exposure
techniques because we are trying to build a new set of memories – what many
professionals call a “safety memory.” Let me explain.
Think about the police
office from the previous example. Prior to the trauma, things like guns,
sweaters, facial expressions and even blood didn’t bother him. In fact, these
things usually don’t cause much fear in most people. This is where we want to return
– to having all the things in the “fear/ trauma memory” go back to normal.
The research shows
that we do this by using exposure therapy in safe settings (ex: therapists
office) and in a particular way that allows new memories to form. Over the
course of sessions and repeated exposures to all kinds of feared stimuli, things like the
sweater develop new and strong associations with safety and normalcy.
Now, does the old,
fear/trauma memory disappear? No, it does not2. What seems to happen is that the
new “safety memory” that gets developed in therapy inhibits or prevents the old
memory from getting activated. In fact, over time and in certain settings the
old memories might get triggered again, even when therapy is successful. This
doesn’t mean therapy has failed – in fact, most experienced psychologists
anticipate these situations and develop a plan with the client.
In terms of the PTSD
beliefs that get developed after the trauma, part of CBT involves working to
change these as well to something more healthy and adaptive.
So, for those first
responders suffering from PTSD, science has yet to find a treatment that allows
us to erase those memories. but there are excellent treatments available that help rewire your memory
systems and change beliefs. This allows PTSD sufferers to get rid of those difficult symptoms and finally start to recover.
References
1. Shipherd & Salters-Pedneault (2008). Attention, memory, intrusive thoughts, and acceptance in PTSD: An update on the empirical literature for clincians. Cognitive and Behavioral Practice, 15, 349-363.
2. Craske et al. (2008). Optimizing inhibitory learning during exposure therapy. Behaviour Research and Therapy, 46, 5-27.