Hello Ruby I can tell you from my own experience that I have a 0% rating for Breast Reduction (related to back and neck during service recommended by Dr.) and I have a SMC (K) for FSAD as a secondary...the craziest best thing that ever happened to me by the VA cuz I didn't even request it. I was just going in for my breast exam...I answered a lot of questions about current pain and depression related to it that was in 2015... NOTE: (turns out I never should have gotten a breast reduction, two years later I went into another physical therapist for my neck and back, and that therapist was appalled that the Dr. said I should have a breast reduction...according to her it was a core (abdomen strength) issue)...that was back in 2008...
Yes, you can get secondary to 0 rating...