[Ulzgoroth]

Well, "constant compulsion" isn't far wrong, but I question what makes that a "psychological extreme".

I'd generally be okay with giving more or less 'normal' people such disadvantages with easy Self Control numbers...but that's because there's a certain rules passage I generally ignore:
"You never have to try a self-control
roll – you can always give in willingly,
and it is good roleplaying to do so.
However, there will be times when you
really need to resist your urges, and
that is what the roll is for. Be aware
that if you attempt self-control rolls
too often, the GM may penalize you
for bad roleplaying by awarding you
fewer earned points." (Characters p121)

According to that, no matter how easy self-control is it's inappropriate to even attempt it except in rare and critical cases. Which means that while the Disadvantage might not ruin you as an adventurer because you can overcome it when you really need to, it would dominate the rest of your life.

I think that's dumb, and would allow/use self-control rolls any time the character has any reason to keep their impulses on a leash. But that's a house rule really.