How do I handle a long gap on my résumé? - any advice?

I have been out of work for 6 months and worry about the gap. I am nervous about being filtered out. What do you say in interviews?

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.

I listed the volunteering and course under the same dates and kept the explanation to a sentence in the cover letter.