I'm a sorta-hoarder, which means I haven't cleaned my house or invited anyone over for about 13 years. I just don't attach sentimental value to objects like some people do.
My problem started after 9/11. I felt like the world ended and I just kind of gave up.
Recently I found out that I'm an empath. I've come to believe that people with depression, agoraphobia, hoarding disorder, and many other problems are actually empaths. We're sensitive to other people's feelings to such a degree that we can't function. We often can't watch the news or violent movies because it traumatizes us. We often just want to hide.
Here is a link if you're interested: http://www.empathtest.com/
Life's getting better for me, finally. I hope this helps a lot of you.