Lycanthropy

For the people that don't know what lycanthropy is, lycanthropy is a physical or mental change into a werewolf. A "mental" change is when the person believes that he or she is a werewolf, which was quite common in the Middle Ages. While this is a rare belief today, people with rabies have been proof of werewolves until they found out that rabies is a disease transmitted by animals, not by a curse. To say it is a curse is a bias comment because to say it's a curse is to take sides with the european/hollywood version of a werewolf. In native americans, werewolves and other were-beasts were considered to be good and didn't picture people as "snacks".

What do you think is the most reasonable version of a werewolf?