Nmda antagonism is inherently neurotoxic iirc
Also, THH is an MAOI not SSRI, unless there is new literature. These are both antidepressants which increase the amount of serotonin in your brain but have very different mechanisms. Monoamine oxidase is an enzyme that breaks down many endogenous chemicals (monoamines) that are in food, inhibiting them allows the dopamine, serotonin, tyrosine, etc. In your food into your blood. SSRIs stop (slow) the reuptake of serotonin leaving more to bind to ht2. You probably already knew this and shit but I don't think THH is ssri.
I'm quite familiar with MAOIs personally, THH is a RIMA but it's also an SSRI according to this citation: Morales-García JA, de la Fuente Revenga M, Alonso-Gil S, Rodríguez-Franco MI, Feilding A, Perez-Castillo A, Riba J (July 2017). "The alkaloids of Banisteriopsis caapi, the plant source of the Amazonian hallucinogen Ayahuasca, stimulate adult neurogenesis in vitro". Scientific Reports
NMDA antagonists also aren't inherently neurotoxic, but most that are recreationally used are. Arylcyclohexylamines and diarylethylamines for example, but I don't believe memantine, bromantane nor agmatine are, just off the top of my head. I also don't believe nitrous oxide would exhibit neurotoxicity if it didn't plummet B12 levels, so if there's an analog of it that doesn't ravage B12, maybe that too.
Oh and what you guys are thinking of in terms of nmda antag is rychnophilline (spelling?) It is in cats claw too.
I have smoked cats claw and drank it as tea and experienced what I'd refer to as the most barely noticeable dissociation possible, similar to agmatine in high doses. It was oddly effective for getting chores and shit done. This was during a period of my life where I was using a ton of random ethnobotanicals, my "ayahuasca era". I found cats claw much less impressive than high potency kanna extracts, blue/pink lotus, b caapi and its extracted/isolated alkaloids, psilocybin containing mushrooms, coca, ephedra, and HBWR. Those all kind of won my attention during that point in my life, but now knowing there's NMDA antagonism in cats claw I want to try to figure out the most optimal extraction method here if I can.
I brought up that list because it was everything I found meaningfully psychoactive and useful in the ethnobotanical space, and I made a grid out of them, then trying each in combos with one another, then selecting the interesting two-drug combinations and exploring how to expand them from there. Cats claw I tried with almost everything on that list above, and noticed it synergized with lotus and caapi a little bit, but not to an insane degree, and there's also very little that doesn't synergize with caapi imo.
Have you ever used cats claw alongside kratom? How was it?