Acronym for: Post Holiday Depression
This condition develops when one returns from a nice holiday, and resumes their ordinary daily routine. Depression occurs as a result of carrying out boring tasks such as work in place of relaxing/partying.
Person 1: ''how was _____ (e.g. kavos) ?''
Person 2: Sick bro, but I'm already getting some serious PHD. I've got work in a few hours.