This article was just shared on my FB feed, although its dated January 2015.
It suggests that depression could be an allergic reaction to inflammation
http://www.theguardian.com/lifeandst...-immune-system

This would certainly support my theory that IIH (http://www.iih.org.uk/what-is-iih)and depression are linked; I get heightened symptoms of anxiety and increased lethargy when my other IIH symptoms are present.
Anyway, I thought it was rather interesting!