No kidding on Serotonin Syndrome. I've had this 3 times, though it mixes with my psychosis so I can't really separate all of it out. Basically put I think it causes an elevation in symptoms in general, and puts you in a manic psychiatric crisis mixed with whatever else you have wrong with you.
First time (Zoloft) I had exacerbated my existing non-diagnosed psychosis into the point of not knowing what was real and what wasn't at all. Like I didn't know if chairs were real, nor if the alien voice I was hearing was real, nor what my real name was or if the nurse was a government agent. Eventually this led to a diagnosis of Schizoaffective Disorder through emergency psychiatric evaluation and like 2 months worth of work to bring me down.
Second time (Celexa) I thought everyone was wearing these white masks and I was a ghost haunting them by becoming an enraged spirit, then the official above-God like leader hated me. I wandered around in the woods in the hail and almost got sick.
Third time (Geodon) I was put on suicide watch since I felt there was an urgent need to end my life to save the world.
Then again, this isn't even getting into how screwed up the rest of my brain and other false beliefs can be, so typical Serotonin Syndrome may vary. Although I can confirm I've never gotten Serotonin Syndrome from LSD, the most I've ever done is 2.5 tabs at a time.
