Jonah-what did he do?

Hi all, I'm new to the group and haven't followed the family all that well until recently. I'm trying to figure out what Jonah did that his parents feel a grown man needs a babysitter. I think he was hospitalized once for doing a drug one night?----but anything else? I just don't see 1 mistake as a good reason for being so overbearing with him. Then again- they are overbearing with ALL of their kids. It's like none of them get to just BE adults. SO odd!