If you can actually manage a dosage regimen of ketamine or - if others turn out to have the same mTor related AD potential - other dissociatives at an appropriate AD dosage which is much lower than a recreational dosage for ketamine, the concerns related to abuse (i.e. taking too much too often) wouldn't really apply. So the analogy with kratom becomes irrelevant.
If kratom had a therapeutic potential at dosages that would make it's opioidergic action insignificant, your concerns - while valid in your example - would not apply.
Thus, it's mostly a matter of willpower or, what I would say is a much less risky way, to disconnect one's idea of the drug as anti-depressant from it being recreational, somewhat similar to disconnecting the application as an anaesthetic. You don't want those applications to mix into some grey area IMO which is the point. If you want to use it as an anaesthetic, you do everything to prevent emergent phenomena: you do not want someone on an operation table to be partially aware and have a trip. Separate the applications to avoid problems. If done right, it is inappropriate to be overly concerned about effects that are relevant at a particular dosage level but not really relevant at very different dosage levels.
This is an important thing to realize before outright dismissing therapeutic potential. It is a different matter (maybe theoretical vs practical) that too many people mix up recreational effects and interest in recreational aspect with therapeutic potential or even a therapeutic potential which is highly hypothetical and complicated.
That a lot of people mess that up doesn't mean that there isn't any potential, and again: low dose ketamine actually being used now as anti-depressant proves this... the fact that the number of people pulling this off at home is scarce (i think) proves my other point about self-control and sticking to the principle of only seeing it as an AD medication with discipline.
About DXM: I don't know of good evidence to suggest that it has AD potential via NMDA/mTor like ketamine but it cannot be dismissed as a possibility I guess, any subjective effects suggesting it has AD potential probably come from SRI effects. These SRI effects may require dosages which may be too high to be harmless to take daily. I think the therapeutic effect also has a shorter duration than that of ketamine, rather a la tramadol's SRI effect.
So it does not seem justified to take DXM as AD at this point, more data is needed. If anything, dosages might be tried experimentally which are threshold or sub-threshold regarding recreational effect. Still, this may be not be great for your body.
You offer no reason why ketamine is 'not the way to handle things'. View this
https://www.ted.com/talks/rebecca_brachman_could_a_drug_prevent_depression_and_ptsd . SSRI's are a bad example, despite them being popularly prescribed they offer limited potential. The therapeutic effect when compared to placebo is really not so impressive, like 50% vs 60% or 40% vs 50% iirc. The side-effects and withdrawals also tend to be way more serious than anything known about low-dose ketamine infusions and are worth weighing seriously in pro vs con.
Ketamine offers no lasting effects? Well you're wrong and mainly about implying that other anti-depressants can do better: the benefit of low dose ketamine infusion can last up to the order of weeks while starting immediately, while SSRI's require building up blood concentration which can be quite tricky and sometimes dangerous going up or down (far too often people don't get very slowly tapering doses but just relatively big steps because of the pills usually prescribed of e.g. Seroxat). Apart from the nasty dependency this basically causes, the therapeutic effects of SSRI's nor other pharm AD's i know of don't extend longer or as long as that of taking low dose ketamine infusion... once you stop taking it.
Name one anti-depressant which reliably can cause much longer lasting effects?
I am not disputing anything regarding the use/abuse of the thread starter by the way, and I haven't before. Am speaking more generally. Nobody said this must be case specific, considering whether DXM could have AD potential in the first place is worth discussing and I'm not sure if someone else - you maybe - raised that point as sheer impossibility. Mainly I reacted to "drugs cause mental illness" type claims.
If you don't think it's okay that people undergoing low dose ketamine infusion therapy as AD gain benefits because you somehow on principle judge that dissociatives are by definition no good, that seems - pardon me - ignorant and closed-minded. Apparently you have made up your mind that euphoria mediated via NMDA+serotonergic effects among other things, at recreational doses, must mean that something like ketamine is a fake anti-depressant as bad as taking mephedrone as AD. This is false, you clearly are not aware that there is a more subtle mechanism (NMDA+mTor) that does not rely on something like euphoric effects at recreational dosages, is produced mainly by specific metabolites of ketamine and requires only low dosages. It apparently has to do with neuroplasticity - my pet theory to go with that is that dissociative effects may disrupt rumination / overconnectedness in the brain that may often underly depression.
Quoting the DSM shows that yes there are substance induced psychiatric issues. However that was not the point: such states (like substance induced psychosis) typically stop when the drug wears off and are not truly mental illness. If you are talking about e.g. psychotic episodes triggered by psychedelics there is virtually always a pre-existing condition that may or may not have been latent until then. What you claimed: drugs causing mental illness, means drug use by itself producing an illness, an actual disorder, where there was none.
A recent pretty large study showed no connection between psychedelics and mental illness and as was already said: correlations between mental illness and drug use say nothing because you don't know which was cause and which was effect. People with mental illness have symptoms that make them feel bad or dysfunctional (the definition of a disorder roughly), which is usually a pretty good reason for people to take drugs.
Read your DSM / '9 Substance-Induced Disorders' source again (did you actually read it properly in the first place) but now realize the distinction which is made right away between temporary effects and underlying illness. Yes here they consider the temporary induced symptoms disorders and illness but this is not to be confused with what is normally meant with the majority of mental illness (those underlying conditions they mention). What is discussed here is a small portion of mental issues, in a way you should consider these exceptions and not confuse them with the true disorders that these temporary forms may mimic.
I quote your source here:
This is because while psychoactive drugs are in effect, they change mental function. Sometimes this causes symptoms which can
look very much like (look up the definition of mimic and induced please) those encountered with mental illnesses. This does not mean that once the drug wears off (beyond acute + induced effects), this continues! You are pulling such conclusions out of your ass and clearly don't understand properly what you are talking about there, nor apparently what you are quoting.
The difference is: people with a mental illness have associated symptoms at their baseline state. Drugs can cause symptoms and effects but explicitly NOT at baseline. You cannot draw conclusions from what a drug does or imitates during the effects, because people return to baseline after the drug wears off (with the caveat of possible toxicity or damage which this is not about). You would have to research the chronic effects, not make assumptions based on acute effects - it doesn't work like that.
Once drugs wear off, problems can indeed arise: withdrawals caused by the brain having become dependent on the drug (which are often opposite of the acute effects of the 'intoxication'), or toxicity and damage as a result of the drug's activity. I never disputed this (toxicity / damage being real risks), but it is not the same as the classic mental illnesses such as you list. E.g. dissociative abuse tends to cause cognitive impairment which after a while 'heals' on it's own as your NMDA household is spontaneously restored. You would have to have poor understanding to draw the conclusion that dissociative abuse is the main cause of cognitive disease, with a huge portion of such patients having had this from birth. Did they do too much K in the womb? Please. Yet this is the exact same reasoning you use.
Notable exceptions, which exist as I said before - but being exceptions have nothing to do with 'main causes'... do include cannabis triggering psychosis particularly in people with a known genetic trait. I don't know about the bipolar, never heard that - source?
You must always evaluate this on a case to case basis and resist drawing hefty conclusions from associating toxicities and damage as being basically the primary source of mental illness, which is as hefty a conclusion as is possible here, talking about blanket statements lacking any nuance.
The fact that drugs can cause troubles in the brain in particular ways is not the same as drugs being the main cause of mental problems. What kind of logic is that? Please brush up on your logical fallacies in particular this one:
https://en.wikipedia.org/wiki/Association_fallacy for shame
The mistakes made are quite basic and pollute the rest of your reasoning. You assume you understand yet seriously misinterpret some of these matters. I don't come here and act stern for anyone's fun, but that is a problem that someone must point out to you.