Well, I can can tell you that I basically don’t have a depression problem anymore and it took about 30-40 years for me to get over it.
For me the cure was 1) no condemnation (cured the self-rejection), and 2) the consciousness of his ever-present love every moment in my life (cured the bleak-present/future thinking).
It was a process and I had to learn to wait on the Lord for the answer but it is now behind me and I am grateful.
I can only imagine what life would be like without the Lord.
Scary.
I don't know if this is just my opinion, but there are some very depressing things about life. The possibility of hell being probably the greatest among them. I still worry about friends and family re: hell, but there's nothing I can do for them but pray (I have tried talking but that doesn't seem to make a dent).
I know heaven is going to wipe away every tear, but I can't imagine how it will wipe away what we know about loved ones who don't make it.
I wouldn't see amnesia as a solution of course.