To the OP, don't be discouraged by the post I've just quoted. He/she is correct and the Mayo Clinic link just confirms what I said in my previous post. Research, research and research!
Insurance, sadly, does not cover the lights because FDA and The Powers That Be (read insurance companies) are as yet unconvinced that it is not a placebo effect.
To clarify: My own personal experience is that is
not a placebo effect.
Add light. See my previous link. Lots of light, even flourescent and LED! Try any kind of increased light before investing in a really expensive specific SAD light box to see whether even a little increased light has a good effect. If it does help, by all means spend the $$$ for a specific SAD light box. Of course, if you have the money to spare do buy a state of the art box now!
Eh, in *good weather years* I'm off the drugs completely with much increased light. I have a state of the art $$$ light box without the full spectrum bulbs these days.
In really *bad weather years* I'm on half the dosage I was prior to light therapy. If it is a placebo, I'm just happy to be subject to it!
Final caution, some of those fancy $$$ light boxes are just aimed at the Winter Doldrums folk who don't have SAD but do have lots of money to spare. Buy carefully and ask your MD for advice.
All the best, and good luck!