A very timely topic. Burnout was exactly what I was thinking about when I opened LW minutes ago.
Three major burnouts here. Two of them were caused by creating and running startups. I'm still going through the third one, but I think I'm on my way to recovery.
The longest burnout, which I went through in my early to mid thirties, was about two years long. The cause was a five-year long software project where I was the lead developer and the CEO. The burnout was pretty severe -- I couldn't bring myself to work, so I had to force myself -- which, of course, sustained the burnout. The key ingredient of the cure, I believe, was a 45-day vacation (yes, forty five full days away from work and without any computers).
(I know a guy who went through a similar burnout -- he's also a startup founder / CEO, here in Russia. He couldn't bring himself to work for several years.)
My current burnout, about five months long so far, was also caused by creating another startup from scratch (inexperienced team, unfamiliar tech, new areas of expertise, full administrative and creative load). The peak was about two months ago, but I think I'm recovering.
As for the root causes, I think I just set the bar too high and compare myself with the leaders way too much. Another contributing factor, I think, is my social obligations, mostly to co-workers / employees -- I take this too seriously. Plus, perhaps, a chronic decision fatigue -- it's not easy to find people to delegate some of the tasks I work on.
Also, I never burned out when playing with stuff, as opposed to working on stuff. If the thing in question isn't a goal I set for myself, and if allow myself to drift freely and explore stuff, I don't burn out.
Edit: And yes, I also trained myself to feel guilty whenever I relax. I have to do something about this.
I have to do something about this.
The irony of this sentence is an important part of a healthy breakfast.
When I try to figure out how to balance personal happiness with saving the world, I think a lot about burnout. If I make a major change - e.g. changing careers - what are the chances I'll burn out and become a lot less useful as a result?
I've never burned out, so I don't know where that edge is for me (plus I suspect the edge moves around depending on circumstances). I'm obviously biased on the topic: there's the temptation to tell myself "This will prevent burnout and make me more effective in the long run" every time I want to do something.
Some things people here have described as causing burnout:
Going through the motions of a religion you don't believe in
Training yourself to feel guilty whenever you relax
Pursuing altruism too exclusively (That post suggests Bostrom's parliamentary model as an antidote).
Do you have more examples? Have you burned out? Are there things that you think have kept you from burning out?