Uncontrollable Urges allows the Keeper to force an Investigator to do an action where the Keeper makes all the choices.
The attacks all seem to state "Attack a monster" but I'm wondering if Uncontrollable Urges overrides this and allows one Investigator to attack another.
It looks like the answer is no. From page 2 of the FAQ:
Q: Can the keeper use Uncontrollable urges to make an investigator attack another Investigator with a weapon? What about spells?
A: No. This only allows him to use a spell, equipment, artifact or tome card. If he forces an investigator to cast a spell, he must choose a legal target. To clarify, if a spell says “choose a Monster”, it may not be used against an investigator (even if playing Story 5). As another example, the Keeper may not force an investigator to use the “Sedative” equipment on an investigator who does not have a Trauma card.
