This story seems to caution readers about the dangers of alcohol. The narrator says that he suffers from the "Fiend Intemperance" and describes the incredibly deleterious effects on his character as a result of his alcoholism. When he is inebriated, he goes into rages, enacting terrible violence on other living creatures. He seems to lose all sense of who he is, and he even describes the longing to make a loving creature suffer by his own hands. Poe himself had a somewhat addictive personality and struggled with alcohol abuse in his personal life.
Further, the story also seems to illuminate the idea that the weight on one's conscience, created by wicked deeds, could very well cause them to reveal their own guilt. The narrator is so careful to conceal the location of his wife's corpse, and yet he feels compelled to draw the police officers' attention to the precise spot, an action that result in his own capture. It is, perhaps, his own sense of guilt that compels him to risk self-sabotage in this way.