If we take your position and apply reductio ad absurdum, we could say that cocaine is a highly effective treatment for anxiety, although of course we know that in the not-so-long run it has the opposite effect.
The reason amphetamines are used for ADHD but not depression is that they've been studied to show that the ADHD improving effect can remain for many months, while the mood-improving effect will taper off quickly if you take them every day. Almost everyone who takes ADHD stimulant, feels a mood and motivation boost ("so happy I could cry" is the common phrase) and then is disappointed when that mood boost stops happening after a few weeks or months will learn this. Attention enhancement is less prone to tolerance, though it still accumulates tolerance too. There are some studies showing that the effects of stimulants in ADHD diminish substantially on a multi-year time frame, and it's probably not a coincidence that many people (though not all) who take stimulants discontinue after several years.
It's pretty reasonable to expect reversing DAT and inhibiting VMAT2 increases oxidative flux, the question is really how much not if. Methheads certainly get "brain damage", but is nudging the average loss from 5-10% to 7-12% "damage"? Is it meaningful? Over 30, 40 years that could very well add up.
A typical legitimate therapeutic methamphetamine dose is around ~20mg (up to maybe 60mg a day). A typical dose used by addicts is around 1 gram. And it's usually smoked, resulting in immediate bioavailability.
These days formulations like lisdexamfetamine and extended release methylphenidate are preferred because they have all-day efficacy with typical duration of action of around 8-12h which carries lower abuse potential.
I am all for people doing however much cocaine they feel they need. In broad daylight - let's just drag that into the light and let people go to the dispensary for cocaine hydrochloride, metered, measured and with warning labels.
Because the war on drugs is a stupid waste of time and lives, but no doctor or medical professional has to justify your own stupid actions.
“People should be allowed bodily autonomy to take whatever chemicals they want” easily and dangerously turns into “People should be able to advertise and sell miracle cures that don’t work as long as their victims are gullible.”
Every snake oil fraudster hides their fraud behind principles like bodily autonomy.
