[seec]

They key word was "radically". Of course, every drug has a typical and general impact on how people behave and you can even notice it in physical movement (everybody expects any drunk person to have pretty bad motor control). But this is just making my point even more, you need to observe the differences between individual behaviors under the influence, not just the difference between their behavior sober and under influence. A drug will amplify certain key aspects of cognition/movement in the same way for everyone, someone who displays extreme specific behavior is just more noticeable because the amplification makes it very obvious, but it was always there in the first place.

I have never heard about cocaine making people paranoid but it is just something that every drug user displays at some point (because of the fear of being found out, judged and maybe having trouble with the police). Even though I am an extremely chill person, I have found myself to be a bit paranoid under the influence of cannabis at times.

And I have a question for you: is it the drug that makes people paranoid or is it that people who are inclined to paranoid behavior are more likely to use drugs, which amplify the behavior.

People regularly using drugs have issues that push them to this abuse, it's not really the drug that are the problem, the root of the issue is really in the people and their personnality/character.