Alternate ending theory
There is a theory to the end of the movie that explains alot of the disconnect with reality. The theory goes that Carolyn did die during the overdose and the whole end of the movie was her escaping her living hell into Heaven. That is why/how Kent survives the car wreck, and the unrealism to alot of the ending sequences: like the fight, the intervention scene, the dinner scene, the weird house off campus, Jeanine's sudden acceptance of Pumpkin, etc. If you notice all these odd things happen after she overdoses.
I know it is a dark comedy and there is the obvious overtone of satire present, but just food for thought!