Had a dwarf do that recently, it was immediately announced that he became a vampire. I'd recommend walling them off somewhere with some food and booze. I don't think werebeast infections happen unless they bit someone while transformed so recruit is probably okay, but better safe than sorry.
If it's a vampire, do I what I do. Dig a new section away from fort, with two chambers, closed with floodgates/drawbridges opened from outside. Make a nice little room with a bed, chests, stands, table and chair. Overlap, designate the area as tavern/meetingplace/temple/office/barracks. Have some chests. After this is done, put the vampire in the farther chamber seal the gate, open the other side. Leave supplies, like booze , some stone, fresh clothes. He's now your new bookkeper.
Next time someone throws a tantrum, send him in airlock, close the bridge after them, open the parts connecting to vampire. Assign his new bedroom as the airlock. Designate him as a tavernkeeper, and put them in the same military squad. He will forcefeed your vampire booze, thus alcohol withdrawal is solved, does a few military exercises with the vampire, he's now practiced a martial art, socialised, and tell the vampire to carve a coffin and a slab, his creativity is sorted. When he goes missing, seal the vampire again and haul off the coffin/slab and bloodless tantrumer, refill supplies until no more tantruming dwarves are left.
Tantruming dwarves are interchangable with tantruming citizien poets in case you run out of unhappy dwarves. Works great for Mayors who ban exports of barrels/bins too.