Thanks for a very interesting article. It seems to me that the brain is a chemically induced electrical network made up of specialised cells and is obviously very complex.
I don't pretend to understand any more than the average lay person but am fascinated by the possibility that we may eventually comprehend the brain's innermost workings.
You say that the brain can easily manufacrure neurotransmitters yet depression is due to, or at least linked to, reduced levels of serotonin so how does this problem occur I wonder? Why does the brain not produce enough? And increasing serotonin seems to work in many cases to relieve depression, by means of SSRI drugs, and such like, so this would tend to support the theory that mental problems are down to some sort of imbalance perhaps?