Va denial - MD updated a letter now?

I was denied secondary service connection of migraines to unspecified depression… I told my neurologist and she updated her original nexus letter. I have resubmitted. Thoughts?

To Whom It May Concern: I provided a letter to xxxxxxxx on 1/13/2036. I noted that he developed a mood disorder (depression) which has been noted to be directly connected to his service in the United States Military (Army). This mood disorder has caused depression, resulting in chronic pain and poor sleep. Therefore he then developed chronic refractory migraine. At that time, I wrote that in my expert medical opinion, his chronic refractory migraine headache is directly related to his mood disorder. It is my opinion that it is more likely than not that his mood disorder caused the development of his chronic refractory migraine headache. I read the opinion of the examiner. While it is true that multiple factors can contribute to migraine in the general population, in this particular person it was the mood disorder and then the chronic pain and poor sleep which caused his particular medical condition of chronic migraine. As his treating neurologist, I have observed that his mood directly correlates to his migraine burden. Thank you for allowing the opportunity to clarify my reasoning in the case of this particular individual.