Like Better Party Syndrome, in that a person who suffers from Party ADD will rapidly change the party they are at. It results from a compulsion for something different, rather than something better. Sufferers become bored at a given party very quickly and may even rotate between several parties in close vicinity.
Guy #1: Hey, man let's find a new party.
Guy #2: But we just got to this one 15 minutes ago!
Guy #1: Yeah, but I'm bored.
Guy #2: Man, you have such Party ADD.