I really am trying my best in life and trying to ignore this thought by focusing on getting better with treatment, but this thought still keeps on bothering me anyway.

This thought is that if you have depression, will the shrinkage of the hippocampus cause you more depression? Since the hippocampus is responsible for the creation of new neurons and sends those neurons off to the feel-good parts of the brain (as well as other areas of the brain) and that too much cortisol kills these newly created neurons in the hippocampus, will that cause more depression?

Or even if you have untreated depression, does the hippocampus even play a role in depression and that even if it were to shrink, that it won't make your depression worse?

Finally, is it debated by many scientists that if you have untreated depression, that a shrinking hippocampus (atrophy of the hippocampus) will even make your untreated depression worse and that if it even plays a role in depression at all (arguments against the hippocampus playing a role in depression)?