Another sufferer here.

I've been fine so far, but I feel that that's down to prevention more than cure. I take at least 5,000iu of Vitamin D3, 1g Omega 3s (in the form of fish oil) and 50mg magnesium daily, have regular sunbeds, and exercise every day, and at the beginning of October, I began using my Light Box again, and will probably continue to do so until around April next year.

Having said that, I don't usually start to flag until the end of January/beginning of February, so it will be interesting to see if I've done enough to keep it at bay.