I'm not here to argue with anyone about anything. Especially neurotransmitters. Because I have an education and background in neuroscience and, frankly, for all your online reading most of you haven't a clue as to how neurotransmitters actually work. And I'm too old (senior citizen) and too tired to educate anyone. You'd anyway have to start with college zoology (human anatomy and physiology) classes and end up in some senior level neurophysiology classes. It wouldn't hurt if you also had some neurochemistry/neuropharmacology classes under your belt. Anyway, I will give you these few pointers:
There are far more neurotransmitters that affect mood and thinking than the three everyone likes to cite whenever talking about these things.
How a neurotransmitter actually works depends as much on what part of the brain it's active in as what it is. Meaning, that a neurotransmitter can have an excitatory effect on neurons in one place, and inhibitory effects in another. Which is why it's dumb as a bucket of sand to spout off about this one or that being a so called feel good neurotransmitter or to say (or believe) that any neurotransmitter has a blanket effect globally in the brain.
And this is the one that annoys me the most: opioids work the way that they do because they mimic natural neurotransmitters called endorphins, enkephalins, et. al.. Therefore opioids are working in a sense as neurotransmitters in their own right, producing their own cascade of effects in neurons that have nothing to do with serotonin or dopamine or any others. Trying, as most of you do, to frame the discussion in terms of only three neurotransmitters, you know, the pop ones, the cache ones, the meme ones, only shows how little you actually know. It's far, far more complex than you seem to realize. You're not really helping anyone with such discussions. You're only jerking each other off.
Feelings hurt? Like I give a shit. Want to challenge me on opioid neurochemistry? If you don't know who Solomon Snyder is or what he did, don't bother. You see, almost fifty years after I graduated from college I still read neuroscience for entertainment. Only I read texts at such a high level of academic complexity that even with my education I only barely grasp a lot of what I am reading. But hey, that's how you learn. And because I continue to learn, it's probably the only reason I'm not drooling into a bib in a home for people with Alzheimer's, which runs heavily in my family.
Having said all that, I will offer this tidbit of anecdote. In the discussion over tramadol, anybody who says that tramadol can't induce serotonin syndrome or can't cause seizures is a complete fool, even if he has an M.D. Like many other idiots I gobbled handfuls of tramadol for years, back when you could buy it online in quantity with no problem. I've only had two grand mal seizures in my entire life, and there's no history whatsoever of them preceding. Both times it was because I took huge doses of tramadol mixed with other drugs that I later learned were highly contraindicated. Because I was a dope fiend looking for an opioid buzz and not taking tramadol for a bona fide medical reason under the supervision of a doctor. One of them was Paxil, an SSRI. Bang. Grand mal seizure. In my home, at night, by myself, immediately after eating a huge meal. When I came to I was on my back. How simple would it have been to die right there, if I'd thrown up, as many people do in the grips of a seizure, and asphyxiated on it. I'd have been found blue and dead by my wife when she returned home from her night shift at work. Diagnosis was exactly that, serotonin-induced seizure as a result of taking two highly serotoninergic meds at the same time. I had a second a few years later, this time from mixing tramadol and a no-longer-available opioid called Darvon or propoxyphene. I had no idea that it too was serotoninergic because I thought it was, you know, just an opioid. But that's another lesson I hope others will absorb: no opiate or opioid is just an opiate or opioid. Every single one of them have knock-on effects that most people don't even suspect. People who take tramadol should never mix it with anything else, recreational or prescription, except under the strict supervision of a doctor. I had friends who were on the same tramadol train to shitville that I was on. Most of them had seizures of their own as a result. One of them behind the wheel of a car moving on the highway. It's a dangerous drug and it's shit recreationally besides. If you're taking it in the huge doses required to get any real fun out of it, you're a seizure looking for a place to happen.
And, like Forrest Gump, that's all I have to say about that.