Getting moving restores vitality. Getting moving is hard without vitality.
That's it in a nutshell.
It's like, when you're alive you have that natural momentum. You're eating regularly, consuming fuel, you're plugged into the world, part of something, immersed in that causal, sensory, experiential, interpersonal soup. You're active, you get tired, you sleep and recharge and heal, you wake up and carry on the next day. Life is the aggregate of all the moving parts, vigour that arises from the biological machine being active, perpetually-refining itself. Life is a dynamo. You keep pedalling and the light stays on.
Depression for me was the momentum of life grinding to halt and the vital essence of living becoming stagnant. The momentum stopped. Routine activity stopped. I was unplugged from the world for too long. Suddenly you look around and the world has moved on without you. Everything is further away, everything is harder to do. It's like being paralysed and having to learn to walk again. Things that came naturally and unconsciously take on a daunting and impossible shape, or slip away entirely. Things that you didn't previously need to think about, now must be thought about and concentrated on to even begin. It's exhausting when even the smallest of tasks become gruelling, and where there is no joy or meaning to any of it. Just cold logic and narcosis.
It is possible to start the momentum up again though. It took a long time for me. I needed lots of help. As trite as it is to say, it was nevertheless so very true: the first step was the hardest, and it did get easier.
Depression is in me now. Maybe it has been there all along. But my momentum is going strong again, affording me all those options and avenues I enjoyed carefree once upon a time - energy and ambition, joy and pain instead of apathy and numbness, appetites, interests, optimism, meaning, honour, dignity, self-esteem, expression, confidence, destiny. I sometimes wonder if it'll all come crashing down again, if it's all just a sham, a precarious conceit, just piecemeal self-help mantra and contrived coping mechanisms, a finite exercise or experiment, not the real me, not my real mind. I don't allow myself to indulge those thoughts, though. That way lies insanity. Whatever this is, I'll take it. This is good enough for me, more than I could have hoped for. When those demons come for me, I'll make sure I'm ready.
Topic: Andrew Solomon: Depression, the secret we share