It does not seem like a huge dosage of Klonopin. And I kind of doubt you get dementia from it. But yes, it can affect memory and functioning. If I take the max dosage of my benzo too long, it actually makes me forgetful and a bit dumb. But backing down on dosage a bit helped, which tells me it's not a permanent thing. When I have cut down to half my max I am pretty normal memory wise, but recently, because of anxiety I have to take 75 % of my max, which leaves me with some memory issues and some fogginess.

Can't explain the impulsiveness though, I've never had anything like that.