Early in the story, Poe's narrator compares his arrival at the House of Usher to the crash into reality that comes after an opium trip. He twice calls this "the bitter lapse into everyday life." He also compares his arrival to the dropping off of a veil.

The narrator tells us he comes to the house after riding on horseback all day through a "dreary" tract of land. It is evening as he arrives, and the scenery continues to be dismal and very depressing as he approaches the house. From the context, it would seem that contemporary readers would understand taking opium as putting a person into an intoxicating dream state that is better than everyday reality. The narrator, they would understand, has apparently been able to use his imagination to envision the House of Usher and its surroundings as beautiful and alluring, like an opium dream. Now faced with the dismal reality, he has crashed. Readers of his time would have understood that crash as harsh and miserable.

A modern reader, whether using drugs or not, would know enough about opium or other opiates to have a similar reaction as a reader from Poe's day. Reality does not compare well to the dream world produced while an opiate is in effect. A modern reader would respond by thinking the house and its surroundings must be especially depressing.