Best Stress/Sanity Mechanics (Aside from Alien, CoC, and Mothership)

Are there interesting mechanics you've come across for PCs dealing with the immediate and long-term stress of experiencing horror-centric stuff, outside of Alien, Call of Cthulhu, and Mothership? Emphasis here on interesting, meaning not just that the game has the usual, totally binary mechanic—characters are either totally fine, and then at some point they're mentally incapacitated. There are lots of examples of that sort of approach, or ones where mental and physical health are wrapped up in a single, abstracted HP-like track. But anything more innovative out there?

What I'm mostly looking for is something that could be grafted onto another game, for example to replace the very boring optional Sanity stat in Traveller. But I also think this is just an interesting topic and design challenge, particularly since a lot of modern games are understandably careful about gamifying and demonizing real-life mental illnesses.