alt Hacker NewsThere are some indications that specific beta-carbolines (harman/norharman) could be a causative factor in genetically predisposed people. Coffee, tobacco smoke and fried/grilled food are the most significant sources.
See e.g. https://link.springer.com/article/10.1007/s12311-015-0751-z
OK but as a high school student I never drank coffee or smoked and I wasn't the type who eats out/unhealthy foods often.
My grandfather on the other end of the spectrum and who also had it didn't do those things either.