I have a busy mind. I also have a busy life which doesn't allow me to quieten my mind.
I find it very hard to switch off, always on the go and thinking. Not necessarily about anything pertinent to my day or anything. I could be laying in bed thinking about anything between what the Queen the ate for breakfast all the way to complex subjects like the origin of the universe. I'm often irate and distracted because of it.
This has allowed (read: forced,) me to slow down. Today I was able to lay in a backyard and read a book with a beer and switch off. I haven't been able to do this for ages.
I'm the opposite, when my mind slows down it allows all the thought I struggle to keep out to enter and I find it very difficult to keep out of the spiral of depression. I am really struggling with the lack of mental stimulation, though to this point I have managed to keep my mind active, the longer this goes though the harder that is going to be!
I'm the other way around, it's very loud inside my head. I'm constantly overstimulated and overwhelmed by it which in turn contributes to my depression. I hope you manage to keep preoccupied though and stave off the black dog. Best of luck with it.
Yeah, my mind doesn't switch off, so I find when I can't fill it with something else the negative thoughts take over. It's why I have been sitting on here so much as it is an input into my head that is mostly positive. Even this morning I got myself into a disagreement with my wife because my mind has had too much downtime. Halfway through cooking breakfast I literally had to walk out of the house to settle my head down. I have been trying to keep my mind active but that is getting harder and harder.