“All successful psychological therapies for PTSD work basically the same way – through fear extinction,” Richard Bryant, an Australian expert in post-traumatic stress responses, told a symposium in Wellington last month.
We acquire a fear response through conditioning: when a conditioned stimulus (the bell ring in Pavlov’s studies with dogs) is associated with an unconditioned stimulus (food for the dogs, or something hugely traumatic), we’ll come to respond to the conditioned stimulus in the absence of the unconditioned stimulus.
So, when something bad happens – say a bomb goes off or there’s a car crash – you’ll associate other things in the environment with that something bad. Smoke, sounds, anything that could be a reminder of the bad something can trigger re-experiencing the traumatic event.
“Extinction” involves allowing a person to experience or think through those smells and sounds to learn that they don’t mean the bad something is happening. Extinguishing the fear response.
The current popular kid on the block is eye movement desensitisation and reprocessing (EMDR). Over a series of sessions, a therapist will prepare the client to work through the traumatic experience and, when the session comes, distract their working memory by getting them to follow a moving finger or light while they talk through the event. The distractor means your brain is too busy to bring down the mental shutters, and extinction begins. In the sessions that follow, talk therapy is used to help the person reframe their thoughts and behaviours.
Bryant, a professor of psychology at the University of New South Wales, says these therapies work for PTSD at least as effectively as anything else we have to deal with mental distress. But before we get too excited, they work for about half the people who reach the therapy room.
One issue, shared with a fair number of other forms of mental distress, is that a lot of combinations of symptoms can lead to a diagnosis of PTSD. The American psychological bible DSM-5 lists the eight criteria needed for a diagnosis of PTSD.
Criterion A requires that you have directly experienced a traumatic event, or witnessed an event, or learnt that someone close to you experienced a trauma, or have been indirectly exposed to traumatic details. Criterion B requires that you experience at least one of five symptoms of intrusive thoughts. Already, that means 20 different combinations of symptoms, and there are six more criteria, each with one to seven symptoms.
Not only has Bryant done the maths and shown there are literally “636,120 ways to have post-traumatic stress disorder”, but he has also looked at how people actually get a disorder, to show this heterogeneity in symptom profiles that all end up with the same label.
Unsurprisingly, our box of successful therapies, all based around the same mechanism, probably works for the 50% of people who have a relatively similar set of PTSD symptoms.
Bryant gave a few suggestions for how to improve efficacy. First, make these therapies more effective for more people – and one way he’s researched to do this is through getting people to do 10 minutes of intense exercise immediately after a therapy session. This appears to promote the production of particular brain chemicals that enhance therapeutic effects. But again, this won’t work for everyone.
So, the strongest recommendation he makes is to tailor therapy to the person in the room – don’t treat PTSD as a one-size-fits-all, and modify your approach to fit who’s in front of you. As part of this, Bryant says therapy should be dynamic, and we should change what we do over the course of therapy to help how someone is in each session, rather than moving through a fixed laundry list of “Session 2, do this”, “Session 3, do this”, etc.
Now, all we need to do is to train more people to do exactly this. Easy!
