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.
These links appear to be about something possibly related but slightly different. These involve treating traumatic memories that already rooted themselves. The post above is about preventing the memories from being rooted in the first place. Sure, they could be related concepts and mechanisms, but they are different.