Dark Emotions Mod is a CAS trait located in the emotional category. Give your Sim this trait and they'll start to randomly experience hopelessness, bitterness, feel fucked up, and emotionally numb.
These were made for EP01 - Get to Work retail stores. They are retail displays with a inventory so that you can store items inside and then stock them directly to surface to set for sale. They will also keep items, like fish, from spoiling as fast. I created these to make it easier to sell all those harvestables and fish at a farmers market or grocer.