I know it will not "solve" every case of depression, however, I really wish people who don't already, would try going outside and/or exercising regularly.
Anecdotal I know, but it seems like nearly every person I know who does both are rarely if ever depressed.
While the people I've known who do struggle with depression rarely if ever leave home.
Again, I know this isn't a catch all for all cases, however, I've seen far too many people turn to meds/substances when lifestyle changes could be all that's required.
It's also a couple of things that only have positive side effects as opposed to most of the medicated approaches people take.
Do you think perhaps it is possible that you have cause and effect reversed?
When suffering from depression lifestyle changes are HARD, especially when dealing with co-morbid mental or physical illness. Conversely a healthy adult of sound mind and body shouldn’t have too much problem deciding that exercise and going outside is beneficial, then just… doing it.