It is, together with stress. You build it up over long period of time because you want to overachieve and you skip on sleep and do other stupid shit to get more out of life. The effects aren't immediate or you think you can be just tough to overcome it but then comes the meltdown which might take literally dozen of years to heal even with therapy. Trust me, I know something about it.
The tricky part is you might not even be able to recognize it. Just like with hunger (I'm not talking about having a midnight snack, I mean The Real Hunger, which is closer to a horrible disease) or thirst. Think about those people who were found lost dead in the desert with their water bottles full, because they thought until the last moments of their lives they still weren't as thirsty to drink their water. No one knows how those kind of borderline experiences feel, so it's hard to recognize them early.
