Is a Nihilist a Sociopath?

A true nihilist, the answer would be no. There's no meaning, no purpose for anything. If nothing has any meaning whatsoever, then there wouldn't even be motivations that would drive any human behavior. One of the reasons people are drawn to nihilism is that there's some sort of a comfort in it. It's this idea of like you can care about everything all at once all the time.