I'm in a similar situation. First, you got the interview, so that already tells you they are willing to overlook the blemish. The gap can be explained with a ton of things. Volunteering, classes, travel to a foreign country or even any odd jobs that seem trivial to you but can be seen as opportunities to learn new skills or a trade like car repairs that saved you a bunch of money. Things you might take for granted just as easily be veiwed as you taking the initiative to broaden yourself, be constructive and not just lay on the couch all day. But even if you can't think of anything, don't beat yourself up over it. You don't have to apologize to anyone for taking time off. It was just what you needed to do then, and now you need a job. As in newgal's example, be confident, succinct and as honest as you can. Just doing that says to the interviewer that you can handle what might be a touchy question, take ownership of your actions and not get flustered.