I suspect the dosing might explain the equivalence. I’ve not come across the study, but if the conclusion was “a 1/100th of the normal dose of cocaine is equivalent to 3 cups of coffee equivalent” I could believe that.
here is a very old one, but oral not i.v.: https://pubmed.ncbi.nlm.nih.gov/4900434/
5mg/10mg amphetamine sulphate vs 300mg and 600mg of caffeine (all oral). The study scales ended up being skewed because one subject had paradoxical response and felt relaxed instead on amphetamines, lol.
If you have access to the full text, check out page 89: fig5 and fig6.
Volkow's lecture may have referenced multiple studies, I've heard that in the context of her lecture on various findings on psychostimulants. amphetamines and cocaine have been fairly repeatedly shown fairly consistent substitutes, so it may have been a study on amp vs caffeine.
She just loves to study and talk about cocaine for some reason, has literally a hundred+ papers on it.
That happens to me and I want to research what it means but your link doesnt seem to work
Being calm and relaxed on amphetamines can potentially mean there is some arousal disorder: sleep apnea, narcolepsy, delayed sleep syndrome, or just chronic sleep deficit. Maybe concussions (mild TBI), amphetamines work for that too.
ADHD is most likely because it’s so common, with sleep apnea being close second. I would rule out ADHD and sleep disorders first.
Potentially also, UARS, which is also form of sleep disordered breathing but not commonly detected with current technology (and also not easy to treat), some physicians do a full nasopharyngeal endoscopy under propofol anesthesia. I believe it’s incredibly undiagnosed and probably accounts for more than 10% of apnea cases, but most patients are thin instead of obese and so nobody suspects apnea-like disorder. If you needed braces or needed corrective jaw surgery UARS should be ruled out.
ADHD can be somewhat objectively measured with some tests like CPT, but that would also show abnormalities in sleep disorders.
If your measures of attention, and sleep study, along with wakefulness maintenance test, if warranted, are all normal, and your blood pressure is normal - maybe you are just a mutant.
See a good neuropsych that specializes in sleep disorders. Stanford is one of the better centres for that.