A depression room is an excessively messy room that's a result of months or possibly years of neglect due to mental health, usually depression. Common objects you can find in this room are rotten or molding foods,
plastic wrappers, used dishes, mountains of clothes, bugs/insects or
small animals (yes, it is very common to find little creepy crawlers in depression rooms), general trash and cluttered things.
The reason it's neglected to be cleaned is because the person who has depression or other mental health issues finds no motivation or
better reason to
clean their room. It's going to get messy all over again, so what's the point?
There is no
shame in having having one of these. People with mental issues are going to find themselves in one of these at some point.