Here is Fiona’s final post on the subject of depression. You can find Fiona online here.
Feelings of spite remain hard to contain. I like to pretend that nothing bothers me, I know this is a lie. Things get under my skin. When something does lodge there, I find myself obsessively engaged with it, turning it over in my mind.
It is like a splinter in the roof of my mouth that I cannot resist tonguing. I hope sometimes that I inflict the same on others. I recognize this as suboptimal behavior.
The concept of a parting shot is weird; the attempt to inflict something while leaving and to remain unassailable because you left afterwards. This behavior is suboptimal because it’s impossible to respond to other than by obsessing, as it is intended. Letting go is the hardest thing because I’m not wired to do so. Petty slights become magnified sometimes—especially by depression—and even the detachment I can feel about physical pain doesn’t do much for irritation and anger. Giving in and lashing out is clearly the rationale behind this, you make someone look weak and irrational.
Some creatures in the Depression Dungeon produce additional petty irritation by being defeated. They scar the victor with a reminder that the engagement is anything but simple. These lingering curses cannot be lethal but are sprung when the player thinks of them again.
GLASS TEETH

“Glass Teeth” Art by Alex Mayo
Glass Teeth (a Spiteful Death Curse)
Upon killing an enemy (such as Mirror People) with this ability, roll a willpower save or 1d6 of your teeth transform into a glass replica. When you next speak ill of them or their kind one of your glass teeth explodes for 1d4 damage breaking your jaw. They cannot explode again until you are healed and they cannot reduce you below 1HP. Many adventurers harden themselves to the depression dungeon by tearing out their teeth—more witty ones use allusion and doubletalk to avoid triggering their curse, proudly displaying their jaw full of iridescent glass teeth.