Comment · Wed, March 20, 2013
Coffee and serotonin
Original post in this thread
Pedrovsky · 33 points
Today I was taking a look at the relation between coffee consumption and serotonin levels. Apparently coffee increases your serotonin receptors and their sensibility, but it also seems to decrease serotonin release.
So the question I want to ask is: On the long term, will coffee be benefitial or detrimental to my serotonin system?
What they were answering
pheedback · 2 points
Maybe. The problem is upregulation can be a sign of a deficiency. When not enough of a neurotransmitter is present, upregulation can occur in an effort to use as much of the available molecules as possible. The opposite of this is when plentiful supplies of a neurotansmitter is around down regulation occurs.
This is why 5-HTP can cause down regulation.
u/MisterYouAreSoDumb
This would not be a sign of deficiency, since 5-HT stores go up when caffeine is used. Did you read the studies I linked? Caffeine causes 5-HT stores to go up, but does not increase 5-HT production. It also reduces 5-HT availability at postsynaptic receptor sites, causing up-regulation. This means that caffeine is just slowing the release of 5-HT.
EDIT: http://www.sciencedirect.com/science/article/pii/0014299971900343
Either caffeine prevents the release of brain serotonin or is able to increase serotonin synthesis.
Since the first study I linked showed it did not increase synthesis, it must prevent the release of 5-HT. This fits with the fact that it causes 5-HT receptor up-regulation and reduces postsynaptic 5-HT availability.