In terms of risk factors for PTSD, what the research has shown us is that, first of all, we understand about half of what they are about. There's a lot that we still don't know, but out of the risk factors that we do understand, generally they tend to be divided into three groups.
The first is the pre-trauma group of risk factors, which includes things like people who have had a previous mental health problem and people who were abused or neglected as children. Interestingly, another pre-trauma risk factor is lower socio-economic status.
Then there are the risk factors that occur during a trauma and they tend to be, again, how severe the trauma is and whether it's repetitive.
Post-trauma, there are also risk factors. Those risk factors, which are also significant, by the way, include lack of social support—which is a big one—and being re-traumatized.
The good news about this is that we can't change what happened to people when they were children, but we can change what we do after the trauma. I guess in a lot of ways that's where our efforts are being deployed.