Before the database troubles somebody (sorry I can't remember who) posted a thread about their ideas for house rules on sanity in 5e. I left up a window on the thread, intending to read it through but never got around to it. If I remember correctly, the idea was something like Sanity being 3 times the character's WIS and then being slowly eroded by the usual experiences and alien researches. I forgot what the mechanism to regain Sanity points was. I did see that the original poster had made an update but I hadn't read that either. Any possibility of the original poster putting it out there again?