https://en.wikipedia.org/wiki/Paradoxical_reaction#Caffeine https://en.wikipedia.org/wiki/Paradoxical_reaction#Caffeine This absolutely happens to my father, w

https://en.wikipedia.org/wiki/Paradoxical_reaction#Caffeine https://en.wikipedia.org/wiki/Paradoxical_reaction#Caffeine This absolutely happens to my father, who uses coffee as a sleep aid but the science is sketchy. It is documented but I don't know if it is scientifically valid https://en.wikipedia.org/wiki/Attention_deficit_hyperactivity_disorder#Paradoxical_reaction_to_neuroactive_substances https://en.wikipedia.org/wiki/Attention_deficit_hyperactivit... I can't find it now but I once read that people who report the "paradoxical reaction" to stimulants have a significantly better outcome from stimulant medications, and both those values seem to have higher heritability than ADHD as a whole, possibly even linked to a single gene.