My friend's dog, Sussi, a springer spaniel, had 5 weeks with me while he moved house. Her arrival was fortuitous as I was in rather a low place at the time. But, quickly, I appreciated that taking her walking across miles of beach every day was doing both of us so much good. We're both built for movement, and, in her case, at considerable speed, especially when a bit of fruitless bird chasing is involved.
But, I also really saw how we were both built for connection. She didn't want to bother me but she always wanted to be where I was, whatever room I was in. Then she was happy. But, the thing is, so was I. I wonder if social isolation is, perhaps, the greatest destroyer of mental health and wellbeing. Yet, a depressed mind is such a lonely mind. What a paradox it is that making connection when we least want to do so actually can lift our mood to make it easier to build more connection.
If you don't have a dog but like the idea of one, well, maybe you can find one to walk, borrow someone's, or help at a rescue centre. If you don't like dogs, well, maybe go walking anyway, preferably with another human. And, of course, there's always cats!