What is most depressing that can happen to a person?

Never experiencing anything significant except for abuse.

That that person gives up on himself/herself

Losing everything you know and love?

Losing a child

The loss of loved ones. Some people never quite recover.

Well, one thing is when family is too busy to come to your second wedding when you have found the time to go to theirs.
That's depressing.

Many things all related to loss I'd think.

Forced to eat donkey balls

Depends on the person, right?

Betrayal by a loved one.

Losing hope.

Death of a child