In a one-shot my DM ran, one of the other players decided to play as a high elf that thought they were a cat and ended up being a drunk 'cat'. I asked if I could use Lesser Restoration to cure the drunkenness (mainly because the player was being very annoying with the drunk cat), under the argument that alcohol could be considered poison – but after hearing the spell description, the DM asked me to cure the whole thing about thinking they're a cat.
I'm not asking if this was allowed in that context, since the DM explicitly allowed it, meaning it was fine then. I'm asking if this would be allowed when the DM hasn't explicitly said that I can.
The description of Lesser Restoration states:
You touch a creature and can end either one disease or one condition afflicting it. The condition can be blinded, deafened, paralyzed, or poisoned.
I was thinking maybe it could fall under the 'disease' portion of the spell, but I needed to make sure.
For added context, this was level 3 and I'm pretty sure the player didn't even ask the DM if they could do that, hence why the DM asked me to fix it.