[cpncrunch]

A lot of the time with depression there is no logical "reason" for it, and no negative thoughts at the time. For example:

- running multiple ultramarathons with too little rest can cause depression, even if you love it. - working very hard in a job you like with too little sleep for a long time can cause depression.

In both cases it's likely your brain it just telling you that you're pushing too hard.

Some people -- like me -- find it easier to get into these mental overdrive situations, and some people might be more likely to suffer depression from the same stressors, but ultimately it seems to be the same factors at work.