That’s what I was trying to say though. There are many factors that go into whether or not people get PTSD, including the nature of the trauma, social support at the time of the trauma, the existence of other stressors at the time of the trauma, the severity of the trauma, whether or not the violence was interpersonal in nature, etc. There’s also a good bit that’s probably genetic. But in research studies, the two things I mentioned have the largest effect sizes on whether or not someone develops PTSD. I don’t even know if I can dig up the research but I’ve posted it here in the past, many times.
I have had PTSD for over 25 years, once pretty severe but now it’s subclinical most of the time.
The most effective treatment for PTSD is prolonged exposure therapy. CBT, cognitive therapy and EMDR are also demonstrably helpful. I’ve had two rounds of EMDR and I have done cognitive therapy for PTSD and prolonged exposure for PTSD. They all helped with different aspects of the multiple traumas I have dealt with.
EMDR is an evidence-based intervention but nobody knows why it works and its proponents seem completely disinterested in learning why, which I find problematic. However, the tetris playing might give us a clue. I don’t think it has anything to do with visual memory - I’ve never had a visual flashback, mine are almost entirely somatic. I think it has to do with working memory. One theory for why EMDR works is that bilateral stimulation occupies working memory, which may affect how memories are re-remembered and affects the negative, visceral charge they have. Just one theory, and it’s the only one I’ve ever heard besides “EMDR is exposure therapy” which, having done both, I really don’t think is the case.
Of course that’s assuming a diagnosis of PTSD has already happened. To actually prevent PTSD is another thing entirely, and the only thing I’m aware of that someone can actually control (assuming they have no control over the circumstances of their life) is yes, playing tetris. What probably would also work is hitting hard and fast with cognitive restructuring as soon as the trauma occurs. Guilt and self-blame and helplessness and all sorts of things are typical after a trauma. When the shame and guilt become entrenched, when beliefs about what happened start to form, that’s where PTSD starts to happen. So if you could intervene in those negative thought patterns right away, it might help.
“Debriefing” which involves talking through things in a group when there is a shared trauma, usually makes it worse, probably because other people’s memories become your own memory. 9/11 is a fantastic example of this, we all heard stories after the fact and a lot of us integrated those stories in our own memories, such that 25 years later I was getting pretty upset about it while trying to relate the gist to my kid, and I wasn’t even there. I wasn’t even close to NYC at the time.