YSK if you've seen something traumatic, playing Tetris for a couple of hours afterwards can drastically reduce the chance of it becoming a deeprooted memory and causing PTSD
A single dose psychological intervention, which includes using the computer game Tetris, can prevent the unpleasant, intrusive memories that develop in some people after suffering a traumatic event.
Downside is, every time you play Tetris to prevent PTSD, it causes you to remember all the traumatic shit that ended up tucked away in the back of your brain from all those previous times you played Tetris to avoid PTSD.