Abstract

In this chapter we review the interactions of oxidative and nitrosative stress (O&NS), immune-inflammation, tryptophan catabolites (TRYCATs) and suboptimal mitochondrial functioning in driving changes in the melatonergic pathways in major depressive disorder (MDD). We propose that such interactive biological processes provide a framework for the development of a number of novel pharmaceutical and nutriceutical treatment targets, with relevance to a classification of MDD that is based on biological underpinnings rather than on subjective phenomenology.