I know I would go absolutely crazy if I could not go outside to do things like ride a mountain bike, eat some ice cream or simply just not sit in front of a monitor every day.
If you are feeling stressed, take a break. :)
Edit:
I know it can be hard, and I know people who suffer from depressions can seem perfectly fine.
A girl I went to school with recently killed herself, much to my surprise, as through my very limited contact with her these past years she seemed very happy in a relationship and about to finish school. The next thing I know she had ended her life. Depression is not something to be taken lightly.
I wish I had known, and I wish there was something I could have done or said.
Correct, no job/task does.
But burnout can, and any task/job/what-ever can cause that if you let yourself get into an unhealthy cycle while performing it. Development seems to be a task that is more prone to this though, I think because with many other tasks (that are more physical) other parts of your body tend to give out first and you have to take a break (if only to sleep or (eventually) pass out if you don't sleep voluntarily) before the point where your brain jumps track.