As someone who struggles with chronic illness and depression, I believe you're right.

I'm not a psychologist, but I've spent a lot of time with them learning about depression and how to live with it. It's all about incremental change. When I realize I'm slipping back into a depressive funk, I have to figure out what I did to dig this hole and start addressing that to get myself out. It's a matter of days or weeks. I'm not special. If I was special, I wouldn't get depressed. I just found what works for me through trial and error.

On the flip side, I have a friend who has been mired in depression for years now. He doesn't try to change his behavior. He has an inconsistent sleep schedule, rarely goes outside his house, eats poorly, doesn't exercise, plays video games 12+ hours most days, and, what I'd say is most important of all, won't see a therapist to deal with his current and early childhood issues. He seems to think that playing more video games, sleeping more, and avoiding any and all unpleasantness will make him better.

I've run into a few people like this and they seem to reflexively write off helpful advice for incremental change. You suggest something like starting out with a 5 minute walk, once a day, just to establish a healthy habit. The response? "A five minute walk isn't going to cure my depression". No shit, no one suggested it would. It's just a start to managing it.

Yeah the thing that is so hard is that none of the individual actions feel successful. But overtime they pay off. You have to build a guest house for happiness and keep it clean. So the next time he shows up, maybe he'll stay awhile.

As someone who spends 10+hr a day working outside I can assure you that being outside and doing physical activity does very little to aid my depression.

mhm... and what if you just had a kid and moved away from helping family to a country which thinks that paid medical leave or reasonable parental leave are luxuries not worth having? have you ever tried to get more than 3h of sleep in a row while taking care of a newborn? good luck going for a run after that! if it also happens to be a winter you may need to wait until spring for that sunlight too. good that we at least have parental groups to socialize... unless you are stay at home dad that is, cause trying to talk about restarting your career after the break might not sit well in a group that mostly connects on how their childbirth went...