Very rarely...when I'm too stressed out about things, I will get tanked so that I can game without feeling guilty about taking some time out to relax. Of course, I have to restrict myself to games that require no thought whatsoever....varieties of RPGs, especially action RPGs, like Fate, for instance.
Drinking heavily really sucks, though. I do it less than once a month (ahem...last night) and I just feel like shit the next day...headaches don't bother me, but wanting to puke my guts up all day does. I don't know how people do this on a regular basis. Ugh.