I've been thinking about this very topic lately. It seems there's a number of reasons why high monoamine levels are bad.
First, and correct me if I'm wrong here, but sustained and long term levels of a given monoamine lead to post-synaptic downregulation. This post-synaptic down regulation may happen via the autoreceptors reacting to the high levels of monoamine release, due to the fact that there's a lot to release for any given stimuli. Or does it happen that post-synaptic receptors grow in numbers due to the large amount of monoamine activity, or presence of monoamines in vesicles "waiting in the wings," and so monoamine activity is enhanced for any given stimuli? In effect, it seems to me that high monoamines would lead to all the stereotypical symptoms of deficiency for a given monoamine, without there being a deficiency but in fact an excess.
The other potential problem I inagine is that we have little idea about what the actual monoamines do to brain tissue when present in large concentration over time. Does the immune system come into play and create inflammation in responce? Does the brain/immune system destroy neurons in responce, again creating a psuedo state of deficient-like symptoms?
Furthermore, how much does overmethylation play into this? Being able to produce neurotransmitters in great quantity might seem like a good thing, but not if you have defective or deficient MAO, COMT, or VMAT activity.
I have a feeling lots of people (and that includes real academics and neuroscientists) would look at the basic question of low activity of enzymes that break down monoamines and assume that couldn't be anything but a good thing. I also have searched, out of curiosity, to treatments for such a problem and haven't found much in the way of any MAO or COMT boosters.
Edited by Dichotohmy, 23 November 2016 - 06:15 AM.