As of right now its literal only purpose is for a few crafting recipes. Why not try to give it some external use like the rest of the stats. I'm really here looking for ideas of how to make it better but have a few of my own ideas.
1. It's called psyche and for that reason alone make it so that it increases the affect that drugs have I.E. how quickly Tobacco reduces weariness, how long you remain high on Opium etc.
2. Make it so it increases the amount of XP you gain from XP events (Since XP is used in magic, it would sort of make Psych increase the amount of magic you can cast since you get more XP, which makes sense for psych to me)
3. Make it alter Quests, but not in the same way Charisma does (Charisma gives you better rewards, so maybe make Psych give a small chance on double rewards based on how high it is.)