Eyeing a cure

PTSD has so many possible symptoms that a one-size-fits-all approach to treatment is impossible

- Marc Wilson

'AIl 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 bad something is happening. Extinguishing the fear response.