postmodem bipolar depression
Unlike the previously mentioned in Urbandictionary 'postmodem depression' which is the feeling you get when you haven't had access to the internet for a long time, like several minutes. Postmodem bipolar depression is the feeling you get when your internet connection keeps going off: when it's up you feel happy and excited; when it's down, you feel sad, lonely and helpless. This can happen several times in a day.
I haven't seen your sister for days: I've heard she's suffering from postmodem bipolar depression.