[ A little bit of both, with an addition of his own fears of being like his parents. Sick, like his mother, or an absent coward like his father? None of it is all that appealing. ]
Perhaps both. Perhaps neither. The event that caused his fall is, ah... it has more to do with your mother. In the BAU we call it a trigger, a defining event that makes a person... well. Snap. Sometimes it's a death in the family or losing your job... in Anakin's case it's a little more complicated than that.