The only time I've ever been "depressed" was when I was also addicted to high reward behaviors. I know these high reward behaviors are linked to both depression and a lack of short and long term memory. It sounds like high reward behaviors (ie: addictions), small hippocampus size, spatial awareness and time awareness could all be interconnected. Or maybe they're separate causes for the same phenomena. I don't know, but it's worth taking a closer look.

I wonder how much it costs to get my brain scanned.