Sounds like both are losing situations. You don't know how a paranoiac who thinks you're going to mug him will react. He can run away or he can try to deal with you.
At least in the second hypothetical, you are doing the responsible thing and staying at home high, in which case wouldn't you also stay at home drunk?
And for alcohol...
"And the aggression and stupidity wore off as the drug left the bloodstream."
Now, would I rather deal with a paranoiac who thinks I'm going to mug him, or a pissed-out-of-his mind dude, in a dark alley?
Would I rather sit there baked and go "dude, is there someone at the door?" for the millionth time, or go out and have a fist-fight while drunk?
Hm.