A phrase that a depressed person utters when his/her friends are inviting them to do something fun. It can be used as an excuse for getting out of doing something shitty, or, it's most commonly just a sad, honest response to the invitation.
Gary: Hey man, let's go watch monday night football tonight, then we can go play some intramural flag football afterwords.
Steve: I have to work tonight.
Gary: Wow, you must be depressed.
Steve: I have to work tonight.
Gary: Wow, you must be depressed.
by JoeyRogue77 October 5, 2009