It would appear that games like Tetris may help in the treatment of PTSD – there’s apparently a six-hour period in which traumatic memories become consolidated, so something like Tetris, in effect, allows the brain to be distracted for a time, thus reducing the consolidation.  Hence

[p]laying “Tetris” after viewing traumatic material reduces unwanted, involuntary memory flashbacks to that traumatic film, leaving deliberate memory recall of the event intact.

There’s a bit more on this via the BBC.  And, reliably, posters to the b3ta community have been quick off the block doing intelligent and witty stuff with the story.  This one is by Bela Lugosi’s Dad.