My husband was admitted today for a 72 hour?

he was admitted today iton a 72 hour (at the least) hospital...he called me last night at 2 in the morning, thinking that he saw me and my dad out in his parents drive way getting ready to killl him. this is just started this past two weeks, thats why were ( me & kids) are at my folks and he's at his.... he is delirious. what ? why? will he ever be normal again you think?