What drugs are those people screaming and talking to themselves at the train station on?

I need to know which drugs those crashout homeless people that live near the train stations or generally in the seedier places of the town are on so I can avoid them. Which drugs usually causes these people to lose their touch with reality and start speaking to themselves or always annoy others. Is it any specific drug class? Some seem alcoholic, some seem like meth psychosis but idk. I’m high asf so idk if this question even makes sense tbh