Edgar Allen Poe was a very unique writer. In most of his stories he has some element of strangeness. Three stories of Edgar Allen Poe, The Fall of the House of Usher, The Raven, and The Tell-Tale Heart, all show that the narrators were going crazy. Although each story does not have any similarity in plot, all three have the person telling the story losing their minds. Putting this similarity into theme form, each story has the theme of craziness somewhere in the story.
In The Fall of the House of Usher, the narrator seems to be delirious throughout the whole story. For example, he describes the house in a very eerie manner, but then all of a sudden he says that the description we just read was false and then proceeds to accurately describe the house. This shows the readers that the narrator seems a bit odd.
Then later in the story, the narrator claims that Usher dies with his sister in the house and a twister destroys the house, yet he (the narrator) got away alive. This explanation he (the narrator) gives ties the knot that the narrator is crazy. Therefore, in The Fall of the House of Usher, a theme of craziness arises.
In The Raven, the widower begins to turn crazy. At first he seems fine, but as the story proceeds, the widower begins to become insane. He keeps glancing at the photo of his deceased wife, and all of a sudden a raven flies in (or so I think). The raven tells the widower that he will never see his wife again, and the widower becomes depressed, and then insane. This story was very confusing and it was hard to get the actual story, but I believe the widower became crazy...