Fascinating @scienceblocks! There are indeed many pathways to depression. I was particularly interested in the disturbance of dopamine synthesis due to inflammatory cytokines. Mostly because it considers and clarifies the kick start of depressive symptoms resulting from both internal and external stimulus (e.g. stress, inflammation).

The energy expenditure hypothesis explained by means of negative thoughts prompted by interfering with serotonin reminded of the principles of evaluative conditioning: the change of feeling towards a stimulus after pairing it with another that carries a stronger or opposite response. It is quite clear!

A truly comprehensive means to address depression and its signs :D
Very enlightening indeed! Thank you @scienceblocks