That’s a lot of questions lol.

So, the current model of addiction leans towards neurotransmitters being the triggering factor.

That means that whatever a given addiction is to sets off an interaction with one of the chemicals that make the brain go “WOW!”. Exactly which one varies by drug and activity.

As an example, cocaine works with dopamine as the primary neurotransmitter. It causes a lot of it to release at once, and you get high.

All of the addictive drugs do something similar, it’s all about which ones set off which NT/s.

The big ones that get that job done are dopamine, serotonin, norepinephrine, oxytocin, and the endorphins (there’s multiple types). There’s other factors in getting high, but the shit that will dig into your brain and take hold in addiction tend to either trigger those to release (singly or multiply) or bind to receptors for them.

However, that’s not the only thing that causes addiction. Addiction is a more complicated disease than can explained away as only chemicals. The person’s psychological history, social factors, genetics, and state of mind during use contribute strongly to the process.

There’s other chemicals we get from external sources that do the same things, but they tend to have a much lower risk of triggering an addiction by themselves. Weed is an example of that. The addiction threshold is much higher than most recreational drugs, and that’s in part because the receptors they bind to don’t have as strong an effect.

But! The there’s that connects all addiction is that at some point, neurotransmitters are involved. That’s why you can get addicted to things other than drugs. Sex sets off a release of all of those aforementioned big NTs. Thrill seekers tend to get hooked on the norepinephrine. Gambling hits dopamine the hardest.

The key factor is that if something makes you feel good, our brains are hardwired to seek that feeling. The more intense the good feeling, the higher the chance of addiction being formed.

And, yes, the reason different drugs give different highs is that the exact chemicals involved vary, and the proportion of them varies as well. Something that’s more dopamine focused is going to be a more energetic experience, whereas endorphins tend to come with a more relaxed and euphoric vibe.

I gotta give my usual disclaimer though. Other than a quick search to make sure of spellings , I’m pulling all this out of memory. And I’m fucking old, so I never trust my memory 100%. I’m also not willing to write a book here, so I’m leaving out a shit ton of detail in favor of hitting the questions you asked in total. Plus, addiction isn’t high (hah) on my list of continuing education as a hobby, so my shit is likely out of date. That may or may not mean it’s wrong, just that it isn’t cutting edge info. So, grains of salt needed (though hopefully not “bath salts”).

Fwiw, I will add that there’s a misconception about addiction, that there’s a difference between “physical” and “psychological” addiction. There isn’t really. It’s all tied together, it’s just that some chemicals do have an extra oomph because they give a much bigger boost to the NTs involved. There’s also a misconception about specific drugs not being addictive just because they aren’t as fast to trigger it, and the factors like one’s mental state and history have a bigger influence. But they’re still addictive, just lower risk

I can explain regarding opioids. The human body produces it’s own opioids in small amounts, which dock to specific brain receptors (those work like key & lock), which makes us feel good by releasing dopamine and has a slew of other body-wide consequences like changes in core body temperature and slowing down the digestive tract.

Using opiates floods those receptors with more and more fitting keys that stay in the lock for far longer than the body’s own opioids. This is an high that is not reproducible by anything else. But it has the consequence that now the body reduces the amount of receptors/keyholes because the reaction was so intense, creating tolerance.

After a short while of usage, the bodys own opioids are not enough anymore to create a meaningful response - the external opioid addition has completely overwhelmed the miniscule potiental of the bodys own signal cascade. Not adding opioids now leads to withdrawal - the gut starts working like crazy and cramps painfully, you feel cold the entire time, you are depressed, your nose runs constantly, and all this time your whole body and mind scream to get the next dose.

It takes a very careful approach to get the opioid system back into balance. Substitution works as an external opioid regulation mechanism, where the “keys” don’t fit the lock perfectly, but also get “stuck” there for a while, leading to a lower activation and blocking out any additional opioids from doing their work. After stabilizing, it can take pretty long to reduce the substitution to a level where withdrawal is easily manageable, so that the natural system can take back it’s function. People who are predisposed for addictive behaviour might even just keep taking the substitution to prevent relapse.

The “buzz” or high is just the body’s response to an abnormally activated hormonal or neurological system. But dependent on which system for the affect. Maybe a good feel system is extra activated, maybe a bad feel system is suppressed, or some other path.

Alcohol artificially activates your gaba system(calms or excites lots of processes which gives the alcohol buzz/relaxation) which causes it to dysregulate as it adjusts to the presence of alcohol over months and years of regular use. Withdrawals are that you feel depressed and anxious (your brain cannot chill), your judgment becomes impaired (as much as if you were drinking) and you learn alcohol is a great cure for the experience.

Other drugs have similar mechanics on dopamine, or seratonin, or other hormones. And the highs along with hangovers and withdrawals are correspondingly different.

The heightened presence over time dysregulates the body’s affected system. Then short term sobriety leads to drug seeking behavior because the body learned that it’s easier and less painful to take the substance than to wait and doing nothing while suffering and letting the brain learn to restore a baseline.

Do drugs sparingly, and if there’s one you struggle to do sparingly, don’t do it at all.

Lots of edits sry

I don’t know any of the details you’re asking about.

But I can say addiction is defined by behaviour. It may not be exactly what you mean.

You might be thinking of chemical dependency. That’s how nicotine, opioids, and alcohol work. Those are specific to each drug.

Things like gambling and sex addiction are based on different chemical processes, and largely work the same, whatever the addictive behaviour may be.

But again my knowledge here is pretty limited.

I’m going to be very little help here, I’ve spent a short amount of time working on tangential research, but I don’t think your are going to get answers that will be satisfying, because the molecular/emotional aspects of addiction are INSANELY complicated. Hoping someone can step in with an elegant digestible set of answers for us.

I’m no expert, but I do know that dopamine, the reward neurotransmitter, can play a big role in psychological addiction, as opposed to physical addiction to the chemical itself. With respect to physical addiction, your body adapts to having the chemical and craves it, such that you get withdrawal if you cut it out. Some drugs, like cannabis, aren’t physically addictive, but are psychologically addictive. You don’t get physical withdrawal symptoms when you cut out the drug, but you do miss it and your mind refers back to it, which is what makes you want it. I’ve found that smoking weed is far more psychologically addictive than consuming THC gummies, because there is a strong link between the act, smoking, and the effect, getting high, because smoking puts the drug quickly into your bloodstream via your lungs. Conversely, it takes 30-45 minutes for edibles to kick in, so it weakens the link between the action, eating the edible, and the high, which doesn’t come for a while afterwards. Gambling, porn, etc., are psychological addictions that rely on the dopamine (reward) connection.

We don’t understand how the brain functions. Neuroscientists know that serotonin has something to do with it because some drugs effect serotonin production/ absorption/ re-uptake and they also effect mood, but they don’t understand the mechanism.

Even the idea that consciousness and the “self” are located in the brain isn’t as well founded as you might think. It might be a continuation of the concept of “duality” where the body and “mind” are separate. Same idea behind a soul.

Anyway, we don’t understand consciousness which would be prerequisite to explain altered consciousness.