I can see how that would be--I mean, if something drastic is happening in Life, but you're on contract for a light-hearted book, then your angst wouldn't fit with the book and it might be stressful to pretend to be carefree on the page. For me, writing is what I do when I'm extremely happy or down-in-the-depths depressed. I mean, yes, I read during those times--and it is often easier to read someone else's finished, well-organized, entertaining, moving, edited work than to write your own. As a teenager, I kept a journal--I wince reading parts of it now, but it was my truth back then and I seem to have gotten the raw-and-repressed-and-depressed version of adolescence. I used to say that writing has kept me (relatively) sane and saved my life at various stages.
So what do you people do when you're in pain? Do you find your reading varying with your moods? If you write, does getting out your shit on a page help or do you find extreme emotions a detriment?