Yesterday my spellcaster's potion-brewing went wrong and he became cursed. It was called "Curse of Uncleansable Stench". It makes a sim's hygiene need bar always low (so he'll always have bad moodlet)...
I'd like to share a tip here. If you take a look in rewards store, you can find a curse cleansing potion for 500 satisfication points. It has really helped me with new spellcasters.