As someone who has suffered from major depression, I know all too well the negative health effects it comes with. Anxiety too, don't even get me started, but the anxiety is tied to past events which when thought of, cause me distress.
I was hospitalized twice for my symptoms, once over several months I lost over 50 pounds from being unable to eat or get proper sleep. I just slept all day and wouldn't get out of bed unless I was thristy or found something to watch and then I'd be tired again and go right back to bed, sleeping for 16 hours a day without being able to help it.
I'm doing much better now, have a more healthy weight, but sleeping patterns are still and ongoing issue.
Peace!