How does one *actually* overcome depression / learn to manage it?

in my experience you don't.. it just comes and goes.. and sometimes i remember that while in the throes.. and sometimes i don't

good fuckin question

maybe a drastic change in material and social conditions. move to somewhere with good public transit and cycling infrastructure with 20 of your friends, where you don't have to worry about food, housing, or healthcare.
a hyper-individualist society will never adequately treat mental illness because it is incapable of addressing the material causes.
- with 20 of your friends
  If you counted up everyone that has been my friend or even just an acquaintance in life I don't think it would hit 20
  
  Were you home schooled?
  
  my list was of impossible things. have some online friends but they're flaking off lately as our shared hobby gets degraded by the company that owns it
- Who the fuck has 20 friends in this current year??? Check your privileges come on
  
  no like the point is that it's impossible. like pulling yourself up by your bootstraps
- I think this is good advice but I’d say do it after doing some therapy that has helped. Of course everyone experience is different. For me, I was in a black multi year depression, did a big move to try to reset things, and basically just fell in my face luckily I got better after doing some therapy and making another big move.
  above I mentioned my experience with therapy & medication. I did some therapy that got me unstuck then scraped together money for a plane ticket to teach English in China for a year. That was a great reset and then when I came back to the states I was able to do more therapy and really get my shit together. (Then I went back to China lol)
  
  i don't really think of what i said as advice because all those things are out of reach, but if therapy and drugs don't help that makes me think the cause (or a major confounding factor) is something they can't help with like living under capitalism.
  shrink can't prescribe me a place that's tolerable to live and 100 people who care and are happy to see me

Do meaningful shit. Join a meaningful movement to make a better world that's willing to train you to be a leader, that in combination with therapy and medication has done wonders for me

I think I accidentally stumbled into the perfect (for me) solution when I became the 'mushroom guy' in college at the same time that I learned about/became obsessed with meditation. i tripped every two weeks for a stretch of ~6 months while developing a meditation habit and consuming every Alan Watts lecture on youtube.
not saying at all that this like fixed me, it still hits from time to time. we're not broken, just fucked up by our environment, parents, culture, poverty, biology, etc. me cramming shrooms and meditation simultaneously for a year just gave my brain a major reset and helped me develop mindfulness tools for keeping my nervous system on an even keel.
there is some scientific backing to this approach, I've learned about later on. psychedelics can help bump you off mental patterns, and mindfulness can help you create new patterns intentionally.
the key though is in the combo.
- I came here to say mushrooms as well but I think for me it's as much a direct pharmacological effect on my depression and adhd as it is the accumulation of downstream effects on my mindfulness toolkit/coping skills. I say this because I can feel my perception change and the effort required to exert my attention climb around 9-12 months after my last trip and these changes evaporate nearly immediately post trip. Maybe I wouldn't experience this if I went back on methylphenidate but the side effects got rough as I got old
  there is some scientific backing to this approach, I've learned about later on. psychedelics can help bump you off mental patterns, and mindfulness can help you create new patterns intentionally. the key though is in the combo.
  100%
- gunna do this but with m*th thanks
  
  I'm gonna do this but with chloroform

Therapy and medication did nothing for me either and I still have my struggles, but doing a lot more physical stuff (not just exercise but meaningful physical activity IE certain types of volunteer work), getting 7-8 hrs sleep as many nights as possible and strategically limiting screen time has definitely helped.
Oh, and weed (and hallucinogens once a year or so).

First, I’m sorry you’re having to deal with that. I know how hard it feels to have your life be unenjoyable and bleak.
I tried meds and the did fuck all other than making me dizzy.
I eventually hit a sort of rock bottom and also almost simultaneously found a therapist and therapy situation that worked for me. Luckily enough it was at my university’s mental health center. CBT methodology worked really well and I still use some of the stuff I learned now, more than 10 years later. If I were to go back to therapy I’d probably look for someone who did DBT. Lots of good evidence it works well for depression.

Can't say this is a "solution", but negative thinking is habitual. Our brains are hardwired to reward repetitive thinking by strengthening the connections we use the most. This is the same mechanism that allows us to get better at tasks through practice.
Unfortunately, our brains don't differentiate between positive or negative thought patterns. It doesn't reward us when we think good things, while punishing us for thinking bad things. it just makes it easier for us to think about things, that we think about often.
This means that negative thinking reinforces negative thinking...making it easier and easier to have negative thoughts. It becomes an automatic function that our brains execute like muscle memory.
The only way to stop this from happening, is to force your brain to think about something else...and repeat it often enough, that the new pattern takes priority over the old one. Eventually the new pattern will become as automatic as the old one, and will no longer require effort to execute.

page me if you find out won't ya

I hear you, I've been in deep bouts of depression since my early teens.
In my case, I started to consistently feel better when I became a part of a community that was doing something. Organising, taking some form of action, and connecting with people who had shared goals and who've been through similar struggles as myself.
Over the years I've worked on my depression by myself a lot, engaging in hobbies, working out, etc. but the improvements were always temporary. It wasn't until I started fighting for something with others that I stopped sliding down into the abyss, even through bad days.
It's just my experience, I hope you can make it out as well.
- My brains broken from years of isolation as a child so I just really hate going out in public and seeing people. I've done volunteer work for a local festival, I've done canvasing for a vegan group, shit like that doesn't help. Having to deal with people all day just makes me want to peel my skin off
  
  Everyone tells me diet and exercise. That would probably help if I did diet and exercise but who's got time for that not me lol. Can you get a puppy? My dog keeps me from the abyss

Running every morning is the hardest thing to imagine doing when you're depressed. The worst part is that it works.
You're right about it being more about management than "overcoming". I've also found, and heard others say, as you get older it naturally loosens its grip a bit.
- Running every morning is the hardest thing to imagine doing when you're depressed. The worst part is that it works.
  cart before the horse. people well enough to exercise benefit from that exercise but they were well enough to do it in the first place.
  
  I know, I am/have been in the same situation as OP. I don't want to sound like a rise-and-grind guy, but when you get a little relief it's something to keep in mind. It will make that period when you feel okay last a little longer.

I'm going to be trying esketamine treatment soon. I'll tell you if it's helpful. As with other commenters in this thread, I've had incredible periods of relief after psilocybin shrooms. Just 4 trips, but that was followed by months of improved mood and functioning overall. I'm hoping esketamine is similarly effective for me. It's legal and FDA approved now by the way, so perhaps look into a psychiatry practice near you that provides the service.
- I've been doing esketamine treatments for a while. In my experience, they have helped a good bit, but shrooms have been a good bit more effective (probably at least partly cuz I can take a big dose, but with the legal esketanine they just give you a fixed dose)

The book 'unsettled minds, strangers to our selves' , gives four varied examples of how material conditions often cause then exacerbate mental conditions in different ways. I thought it was insightful.

Volunteer somewhere. Getting out and having a scheduled thing helps.
If not, you're still miserable but at least other people benefit from your help and are happy.

My approach has been to lean into hobbies. A few of my favorites include: audiobooks, leather working, and managing a home server . I find if I microdose any of those while the dark thoughts are creeping in, these act as my patronus.
Maybe it's a safety blanket kinda thing? Not sure. Good luck
- I don't have really any hobbies and whenever I try to get into something I lose interest very quickly. I just can't get invested in anything because I have no passion for anything
  
  Might be possible you haven't found the right things yet. There's a lot of possibilities, the challenge could be in getting yourself to try something new every once in a while, with the hope that one day a spark will turn into a flame.
  May the wind be at your back and the sun upon your face, and the strength of your heart carry your foot when all else fails

Estrogen was the solution to my depression. I don't take antidepressants anymore and I'm way happier than when I was on them.

I would post a joking answer "that's the neat part, you don't". But my actual honest serious answer kinda ends up lining up with that anyways in a really depressing way, I really don't know. Like the only thing that has kept me going so far despite my self-hatred, and depression is keeping myself busy/distracted from it.

By having a less miserable life.
It's not all in your head, despite what the CBT nutters say. Nor is your brain chemistry corrupted like a faulty hard-drive. All of this shit was made-up by bourgies so people won't blame the societal structures they live under.
Unfortunately a lot of things that keep us miserable are out of our control, or take an extreme amount of work to try and change your circumstances to something better.
- This is like telling someone with broken leg to walk it off.
  Dangerously bad advice.
  
  well I'm glad it's a completely one-sided matter.
- All the things that make me miserable are pretty much out of my control
  
  I need money and no one will fucking hire me. I even applied and got an interview for a position cleaning up literal shit at a hospital and they still didn't hire me. They won't even let me clean up doo doo feces to make a living
  Can't get SRS without money, can't get FFS without money, can't get out of my shitty ass apartment where they're always cutting the water off without money, this shit sucks
  
  All the things that make me miserable are pretty much out of my control
  Yeah, same here. The only thing I'm certain of is that mind-numbing psychiatric "medications" and learning to hypnotize myself into denying my own thoughts (aka "Cognitive Behavioral Therapy") are not the answer, and that it's mostly about the material causes.

I cut down to one or two drinks a month, became more aware of my own emotions and developed some responses to them that help even things out.
Having a normal routine helps. Like a “normal person” routine where you go to sleep at a reasonable hour, get up at one as well, eat healthily, exercise, wash yourself, spend time outside etc. making it a routine means it’s something you do automatically.
That was really hard for me for decades. Sometimes I’ll still be awake far too late or skip a shower and have to catch myself.
- I never manage to stick to routines, if I have one slip up I spiral and it all goes down the drain. I was doing pretty good routine-wise for some of March but all it took was one bad day and all the progress was washed away
  
  habits take quite a long time to form (i think a ~month normally?), and if random twitter threads can be believed (lol), it is even harder if not outright impossible for people with adhd
  
  I know how that goes. I had to learn to recognize my own emotions and keep from letting them control how I go about day to day life.
  It’s weird to say but the same technique of feeling the emotion then putting it away for later that helped me control acute feelings like anger and sadness also helps me keep from getting disrupted by emotions that slowly well up like depression.
  Of course there actually has to be a later. There has to be a time when that stuff gets expressed otherwise it just builds up and overcomes your ability to function.

I know it is a cliche that doesn’t tend to really help people in a crisis but, I’m being really honest here, the only thing that works for me is to eat well, cut out drugs and alcohol, and exercise a lot.
You need to do more for sure. Work on yourself. Get meds. Do therapy.
But definitely eat well, cut out drugs and alcohol, and exercise a lot.