Totally anecdotal, but I wonder if it's related. Two nights ago, I was out with friends drinking and playing pool. We normally go home at 3AM, but this time we went to another bar after and stayed there until 10AM. At some point, maybe around 8AM, I became incredibly happy. Euphoric is actually the word I used to describe it at the time. I wondered if I'd been slipped ecstacy or something, since I was so happy beyond anything alcohol usually does.