On a very important level: it doesn't matter. If you're depressed to the point of non-functional it doesn't matter if changing your situation would help because

On a very important level: it doesn't matter. If you're depressed to the point of non-functional it doesn't matter if changing your situation would help because you're non-functional--you can't change your situation. Getting on antidepressants, or getting into counseling or therapy can (obviously no guarantees) get you out of the trough so you can make the changes you need.