"I don't give a shit" syndrome is the vulgar term for senioritis and other times in a person's life when he or she does not care about the given task or topic.
Although it is mainly for seniors about to graduate college (or high school), it could be used by any student at the end of the semester, or others who are just not interested in the given scenario.
Professor: "Good luck with finals"
Student 1: "Thanks. I'm gonna need it. I have ID-GAS Syndrome."
Professor: What's that?
Student 1: "I don't give a shit syndrome".
Professor: "Oh..."
Acronym for "I don't give a single fuck". A variant of idgaf and idgf, for when the amount of fucks you give are so few that you don't give not even a single one.