n. The depression, worry, frustration and angst resulting from a friend or loved one's own depression, centering around your desire to help and their rejection of your help, and the feelings of sadness and helplessness you feel as the relationship suffers or even ends as a result.
v. The process of destruction of a friendship or relationship with a loved one due to their intolerable and miserable attitudes and behavior resulting from their long term, untreated depression.
"I'm starting to feel defissioned because Sally is mad at me again for not being supportive and attacking her when I suggest that maybe it's not that people are being mean to her all the time but that her perceptions are warped from her long term depression and she really needs to treat that to solve the problems."
"Joe and I aren't talking anymore, everything is defissioning because he refuses to get his shit together and go to the frickin doctor!" (colloquial)
"Dude, you have two options: defission with all your friends, or go get help."