In the case of serotonin, the most potent releasing agent is the drug ecstasy which basically drains your brain of not only serotonin but also tryptophan, the amino acid precursor. This is why, unsurprisingly, you feel rather depressed after an ecstasy “trip”. As a side note, next time someone tries to tell you that depression has nothing to do with serotonin, you can helpfully point out ecstasy, where serotonin depletion causes a perfect analogue of depression (albeit for a few days only).
