For Roderick Usher fear itself is worse than whatever you actually fear. In fact, fear is responsible for at least one of the deaths in this story. One possible interpretation of the tale is that the fear of some dreaded occurrence actually manifests it in reality; that is, because the protagonist fears his death, he brings about his death.
Roderick only fears fear itself – his fears focus on no tangible ends.
By the end of the story, the narrator comes dangerously close to being as fearful and paranoid as Roderick is.