I live in the pacific northwest where not only does it get dark around 4pm but it rains. All. The. Fucking. Time. Living at sea level means low atmospheric pressure anytime the clouds are here, so on top of no light there's also no physical energy. Stagnation happens easily. I really hate this time of year, it's one of the reasons I'm getting the fuck out of here. I visited the interior of this province in September and as soon as I left the coast, all my physical pain went away, along with my migraines.
Vitamin D, rhodiola, regular exercise (especially cardio), stretching, and trying to eat as well as possible are the only way to keep me baseline. If I slip at all and don't do upkeep, I get such fatigue that I can't go to the gym, and then it's a downward spiral. This weather makes everyone here anti-social so on top of everything, it's harder to connect to people at this time of year.
Honestly I think it's lack of light and low atmospheric pressure that causes the insane dolldrums. Vitamin D will never replace sun. Sometimes I go to the tanning salon and it helps, even if I just do the stand-up tanning for 6 minutes or so.
I don't believe humans were meant to live in these conditions. We need warmth, light, and clearer skies. Anytime the clouds roll in it feels totally oppressive. I try to explain this to people but some don't believe me. Everytime the barometer goes down, I get way more calls from people to come for therapy. All their health issues act up... arthritis, fatigue, depression, insomnia, etc. The only people, and I mean ONLY people who seem to enjoy this time of year here are people with high blood pressure. Once the rains come, they sink to baseline and feel great about life. Everyone else wants to off themselves.
I really need to GTFO of here.