polytrip said:No, classic psychedelic's do not elevate levels of serotonin. They cause serotonin levels to drop. If no MAOI's are taken, serotonin syndrome is not a probable scenario at all.
DMT and other classic hallucinogens stimulate serotonin receptors, but as a result of that, serotonin levels drop and serotonergic activity is diminished dramatically. Some psychedelic's like LSD or mescaline increase levels of dopamine on the side. DMT and shrooms do this only in a very modest way when taken in large amounts.
Substances like MDMA increase levels of serotonin, but all of the classic hallucinogens hugely diminish levels of serotonin. Increasing serotonin levels is very likely to reduce at least some of the symptoms of psychedelic's. Especially the psychological effects.
I think you are wrong here Poly. Serotonin syndrome is not caused only by excess serotonin, but by any agonistic action or overstimulation of the 5HT receptors. This "classic" psychs do in spades.
Wikipedia (not a fool proof source by any stretch) says this :
"It was originally suspected that agonism of 5-HT1A receptors in central grey nuclei and the medulla was responsible for the development of the syndrome.[39] Further study has determined that overstimulation of primarily the 5-HT2A receptors appears to contribute substantially to the condition.[39] The 5-HT1A receptor may still contribute through a pharmacodynamic interaction in which increased synaptic concentrations of a serotonin agonist saturate all receptor subtypes.[1] Additionally, noradrenergic CNS hyperactivity may play a role as CNS norepinephrine concentrations are increased in serotonin syndrome and levels appear to correlate with the clinical outcome. Other neurotransmitters may also play a role; NMDA receptor antagonists and GABA have been suggested as affecting the development of the syndrome."
The studies referenced seem above reproach.
Furthermore, on the list of known causes of SS LSD & 5 MEO DPT are both featured along with DXM, MAOIs, RIMAs, Amphetamines, Cocaine, Ginseng, St. John's Wort, Tryptophan, SSRIs, SNRIs, various Opiods etc. It is safe to say that DMT, Mescaline, Shrooms etc. would also be indicated despite not being explicitly mentioned. All the common tryptamines show up on the list.
Individually, even at extreme doses, none of these things is likely to cause a serious serotoninergic toxicity, but in combination... people have died. And, as APOC mentioned, many of the physical side effects associated with a negative trip report mirror SS very closely. Considering that 5HT overstimulation is likely a spectrum, this is not surprising that people would have uncomfotable reactions even well below life-threatening levels. Also, it should be said that people have been diagnosed with SS even from taking only one substance on the list.
It is not a good idea to give people the false idea that simply because serotonin levels drop with certain classic psychedelics that they are therefore free from serotonergic overstimulation issues. The fact that these chemicals are well known to stimulate the 5HT receptors is not debateable.