Poe certainly had a sad life. He was a typical struggling writer who even burned his furniture at one point to stay warm. He found success with the Raven but then lost his wife a year or so later. If Poe had the medical advancements of our day, i bet he would havebeen diagnnosed with paranoia and depression; both for which I think he self-medicated with alcohol.
The character of Usher is totallly paranoid as well as depressed and superstitious. Put all three of these mental illnesses in an old neglected and possessed house and the combination clearly leads to insanity.
Usher was lonely like Poe must have been. Usher's mind obsesses over circumstances he either cannot change or is too despondent to address; possibly like Poe too.
In the end, a life like that isbound to crumble just like the house did.
Thank You . This has helped a lot .