Does Alcohol consumption deplete Serotonin?

I have been reading how Serotonin helps regulate our moods. It occured to me that the alcoholics I know are also chronically depressed. And so I was thinking that it might be a vicious circle: Drink to escape depression - and then deplete Serotonin so you become more depressed.

Does anyone know if it really does work that way?

That’s the short version, according to a 1991 study:

Though it is hard to determine serotonin levels in the brain from blood chemistry, because it does not pass the blood/brain barrier.

I thought so too until I looked it up on Wikipedia, which implies the exact opposite happens (see:Causes). I know it is sometimes innacurate but actually increasing serotonin production jibes well with the warnings on St John’s Wort and other known or suspected serotonin-affecting drugs: namely, one shouldn’t take those if one habitually takes 3 or more alcoholic drinks a day (as opposed to usual warnings about not taking drugs with other drugs.)

The warning makes sense when combined with the Wiki article since if customary alcohol use increases serotonin production, even not having any alcohol at the exact time of antidepressant consumption won’t help, and could still lead to serotonin syndrome (a dangerous overcharge of serotonin) since your body is still pumping it out.

Now, who should we believe: Wikipedia, or a study published by the National Institutes of Health?

My cite does not necessarily contradict Fear’s cite: consumption of alcohol can temporarily reduce serotonin production, which the body then compensates for by making more of it. Of course, if the reduced serotonin production lasts longer than the euphoria of alcohol, the same effect as the OP posited could still happen, albeit caused by the lingering effects of alcohol rather than serotonin “depletion”.

Again I must state that to be fair, I also was of the theory that alcohol and many other substances were addictive due to serotonin depletion before looking it up.

The important thing with serotonin, is to keep it at steady levels. The medicines that raise the level of serotonin in the brain do so by slowing the reabsorbtion of serotonin. The alcohol increases the availible serotonin for a bit and then it drops off quickly, leaving the depressed person feeling worse, and they tend to not take the medicine correctly when they feel badly or are drunk. High serotonin levels do not mean somebody will feel happy or good, It makes it more likely that they won’t feel realy bad.