[mindslight]

24 hours, seriously? In my experience from quitting caffeine cold turkey many times, caffeine detox takes 2-3 weeks. The first 24 hours is relatively easy, on days 2-3 the headache and extreme lethargy really sets in. The worst clears up in 7-10 days.

I think the only meaningful way to run the study is to compare people who are completely free of caffeine, versus people who are steady state a certain level of caffeine per day. Either two different groups, or the same group separated by a month.

This research assumption is right in line with how society ignores caffeine as a non-drug. When asked what drugs I'm taking, I've told doctors things like "500mg caffeine" and they looked at me like I had two heads. Or my aunt who has trouble sleeping to the point of being prescribed benzos, but still has coffee at 5PM. Apparently it's all just "drinking coffee" and not doing a psychoactive drug, because "drugs" are "bad".