To paraphrase a musical once performed by the students of Riverdale High: "What's your damage, Jughead?" In Season 5's episode "Lock & Key," we get a peek into Riverdale's resident writer's psyche, and, as it turns out, he is coping with more than his slew of small town with pep drama.
In the episode, Jughead meets with a doctor who studies UFOs in order to make some sense of why he blacked out on the night that the Mothman specimen disappeared from Pop's Diner. The doc not-so-subtly suggests that maybe Jughead wasn't dealing with an alien encounter at all, but some repressed trauma boiling over. Jughead shoos her away (he'll keep his trauma repressed, thankyouverymuch) but later, he admits to Tabitha that his days of binging on Jingle Jangle and whiskey left him losing a lot of time in New York. In fact...it's possible that he lost so much time, he wasn't able to remember a very important, very bad, situation.
We don't know anything else about what Jughead is dealing with, but we sure can speculate about how bad it must be — if only because Jughead has already dealt with a lot of terrible things.
During his time as the king of the Southside Serpents, he was beaten to a pulp and nearly murdered by the Ghoulies. He was nearly murdered again solely because he was (*checks notes*) a decent writer in an an advanced English class at a prep school. He even faked his own death, virtually attended his own funeral, and had to watch his girlfriend at the time, Betty, be potentially framed for his "murder." That's to say nothing of the serial killers he has tracked down, people he's seen die in brutal ways, and also that one time he became so obsessed with a board game, he almost lost complete touch with reality.