No Stupid Questions

Well, you've already been told the important part, that you can't crowd source this. There's way too much detail that matters to give a good answer without a shit ton more information.

That being said, brain fog tends to be a specific term used by a relatively narrow range of neurological conditions. As it happens, I've been around a lot of people in that narrow range.

So, with the initial caveat in place still, the answer is probably not going to help.

Most of what causes brain fog isn't so much about the things that amphetamines do.

Amphetamines work by boosting dopamine and norepinephrine, basically by increasing the cycle where brain cells pull chemicals into themselves.

Brain fog in most circumstances is caused by damage to the brain cells in one way or another. It isn't going to be helped by a hit of dopamine and norepinephrine. Otherwise, it would respond to those chemicals when administered directly. There are some cases where brain fog is chemical in origin rather than structural or inflammatory causes. But, again, in those cases, there are better options.

Take MS as an example. The brain fog there is from demyelinization. The outer layer of some nerve cells gets attacked my the immune system. The signals no longer get carried properly, and a side effect of that is decreased responsiveness in the brain. A brain fog. It's a structural issue where cells are damaged, and there's an inflammatory response that amplifies the effect.

You can dump all the dopamine and norepinephrine you want into a brain like that and all you'll get is a jittery, stressed out person with brain fog. Wouldn't matter if you took those chemicals, or an amphetamine, it just can't patch over damaged cells. Best case, it slightly decreases the fog by having healthy cells improve function, but it isn't likely, and there's no telling if the improved activity of those cells could bypass the damaged ones and do anything useful.

If your friend is dealing with any of the usual suspects, chances are that it would be a waste of time. It's been tried, and never really does anything useful, or they would get prescribed more often

Now, I have heard that some Parkinson's patients have had a degree of improvement of the brain fog from amphetamines, but that's a dopamine based disease to an extent, so not a big surprise there.

If her doctor isn't willing to prescribe them for her, then there's essentially zero chance it would do any good because they will and do prescribe them for conditions where it can be helpful.

Tbh, I'm not surprised she had trouble finding anything. Most of the diseases where brain fog is an issue, amphetamines were tried so long ago that the journals and publications the data was in were all in print. A lot of that stuff isn't digitized, and you won't find it outside of a medical library. I think the last time I read anything about studies done with them for MS in particular was back in the nineties. And that would have been in back issues of stuff.

It sucks, but she may not ever be back to her old self. She may get better, but never quite back to before. At least, not unless some new stuff comes along. Again, using MS as an example, there's been some attempts at repairing the damage to the myelin. There's been some success with it, and it does come with a decrease in disability. Combined with a disease modifier, that can potentially reverse the problems caused, and keep them from coming back. But that's likely a decade or so away from being ready for patients to have access to. Iirc, it's still in animal testing.

Other conditions have similar attempts ongoing, so it isn't hopeless. But amphetamines have been around long enough to have been tested against pretty much every disease out there. They just aren't viable for brain fog usually